5/12/12Automatic LED Emergency Light Circuit Home About Datasheets Lab Manual Testing Components Electronic Circuits and Diagram-Electronics Projects and Design Search Custom Search Ads by Google LED Work Light LED Power Supply LED Lamp LED Light Bulbs Automatic LED Emergency Light admin February - 23 - 2008 223 Comments Songyang Mach. & Elec. High-quality step motor, BLDC motor ISO 9001, CE, UL certified and RoHS Tunable Diode Laser Single Mode, Narrow Linewidth Highly Stable, 372nm - 9500nm LED Lighting Reduce high utility bills Call us before you buy www.wecogreen.com www.cnsoyo.com www.sacher-laser.com LED Emergency Light We have developed three circuits under Automatic LED Emergency Light. Two of them are designed by Mr. Seetharaman, a very valuable and important contributor of this website. We have ease of reading. If you have any doubts; please comment with circuit name or circuit number. 1. Simple Emergency Light using LED 2. Automatic Emergency Light using LM317 IC 3. Modified Version of Automatic LED Emergency Lamp using LM 317 1. Simple Emergency Light Circuit This is one of the most cost effective (cheap) and simple emergency light circuit developed for CircuitsToday – This is an automatic emergency lamp with day light sensing, means it sense automatically. Similarly it senses day light and turns OFF automatically. A simple emergency lamp which does not require any special equipment; even a multimeter to assemble and use. Any individual who can do a good quality soldering must be able to build this easily accommodated in the defunct two 6 watt tube National Emergency Lamp or any PL tube type emergency lamp. The difference will be in the working; it will work non stop for more than 8 care by the LED characteristic and over charge protection is taken care by the fixed voltage regulator.This uses a simple 3Pin fixed regulator which has a built in current limiting circuit. The only r which has to be set to ensure the LEDs just light up (it should be left at that position). The 5mm LDR is just mounted on top of the emergency light as shown in the photograph. LDR is used t time or when the room lights are ON. 2 LEDs are used in series; the dropping resistance is avoided and 2 LEDs light up with current that is required for a single LED, by which energy is saved t Note: This circuit is developed by Mr.Seetharaman for readers of CircuitsToday. This particular circuit has been kept so simple for people who has limited access to components or in other that you can build with minimum components. In addition to circuit diagram, He has shared photographs of the prototype he made in National emergency light and a PCB design. Simple Emergency Light Circuit Diagram: www.circuitstoday.com/automatic-led-emergency-light 1/31 5/12/12 Automatic LED Emergency Light Circuit Photographs of prototype made in National Emergency Light: Emergency Light Circuit PCB Design: www.circuitstoday.com/automatic-led-emergency-light 2/31 5/12/12 Automatic LED Emergency Light Circuit PCB Design 2. Automatic LED Emergency Light NOTE: Considering the doubts raised by many of our valuable readers in our Comments section, this circuit has been modified by Mr.Seetharaman, one of our valuable contributors. circuit here: Automatic LED Emergency Light Modified. Description: This is the circuit diagram of a low cost emergency light based on white LED.The white LED provide very bright light which turns on when the mains supply is not there.The circuit has an charging when the battery is fully charged. The IC LM 317 produces a regulated 7 V for the charging of Battery.Transistor BD 140 drives the out put.Transistor BC 548 and Zener diode controls the charging of the battery. Tips: It is always better to connect a heat sink with BD 140.Before using the circuit out put of LM317 must be set to 7V by adjusting the potentiometer. Automatic LED Emergency Circuit Diagram: www.circuitstoday.com/automatic-led-emergency-light 3/31 circuitstoday. 3. Street Light Circuit – Want to build a street light application? This is the one you are looking for.please take a look: 1. LED Ramping Circuit – An interesting LED application with help of a ramping circuit.hobby and more of a fun circuit where you can turn OFF an LED with a puff.com/automatic-led-emergency-light 4/31 .How an LED Works You may also like: LED driver IC LED driver circuit Water level Controller LED lamp circuit from scrap Automatic night light We recommend: Car Stereo Amplifier Circuit Diac Applications 5 channel radio remote control Battery eliminator circuit Top 5 Mobiles of 2009 www. 5.5/12/12 Automatic LED Emergency Light Circuit Note: R3 to R14 are all 100 ohms We have more interesting Lighting circuits for you. Puff to OFF LED circuit – A simple. Flashing LED Unit – A circuit application to flash many LED’s. Light Activated Switch – A circuit application to make a switch activated when light falls upon (and vice versa). 4. 2. If you are interested in knowing How an LED works ? Take a look at our article:. 5/12/12 Search Custom Search Automatic LED Emergency Light Circuit Posted in Home Circuits. 2012 at 8:03 am Hi Sarkar you have to use rectifier capacitor etc refer to my mains operated LED. http://www. I want apply only 220v on 50 Leds set (3v 50mA high bright leds ). Santu Sarkar says: April 17. I was going through with the circuit diagram and wanted to work on it. that is once power fails. How to make a 50 leds set. Santu Sarkar says: April 9. I have required any diode or resistor? Plz explain me. Lighting Circuits Tags: circuit design. 2012 at 9:47 am Hi Sarkar you can use my earlier project with 50LEDs of 25mA bright white variety (instead of 3volt 50mA high bright 4 pin variety)replace 1uF capacitor with 0.com/automatic-led-emergency-light 5/31 . Most Popular Circuits. hence it is fully automatic.68uF 400volt polyester required. circuit diagram. This point is taken care in the simple emergency lamp (first circuit). 2012 at 8:27 am Respected sir. it should not glow in the daylight or in the near visinity. hobby circuits.This is not Emergency. if it is dark without any other light source in the ne on automatically. That is on by 220v. seetharaman says: April 10. So I asked you that I have required any diode or resistor? seetharaman says: April 15. Simple Electronics Projects Leave a Reply Name (required) Mail (will not be published) (required) Website Submit Comment 223 Responses to “Automatic LED Emergency Light” Sadiq tobi says: May 4.2uF 400volts no change in other components. Home Circuits.circuitstoday. 2012 at 5:17 am Respected sir. sir i want to know what exactly Automatic means in this project i mean what is the process of its charging and how d complete informations related to this circuit in detail sir i’ll be highly thanks full to you if you reply me for all of my queries and asks i want your support for it because this projects is very m please reply me on my mail address Thank you Santu Sarkar says: www. 2012 at 8:08 am Hi Sarkar automatic means the light should come on once the supply fails (this happens in the second circuit even during day light). 2012 at 5:29 am Hi Mr Seetharaman Plz sir i need d lists of components in d construction of an emergency lamplight using remote control i also need the circuit diagram of dis device.circuitstoday. http://www. hope you want it for 220volts 50Hz operation.com/mains-operated-led-circuit Santu Sarkar says: April 15. hobby projects. Still for automation.com/mains-operated-led-circuit the same circuit you have to use by increasing the value of 1uF as 1.circuitstoday. 2012 at 9:49 pm Respected sir.plz send it to my mail Seetharaman says: April 18. Seetharaman says: March 6.4 v 4. 2012 at 7:52 am I want to know what is the color code & watt R1 to R15? Please mention it. Plz suggest Seetharaman says: March 3. My Main concern is “Should i retain R15 resistor and T2 BD140 transistor in the circuit or not” for Solar powered emergency lite. how m RICK says: March 28. it was made by using 3. so. Day time the light will be off and night it will turn on automatically. i want to discuss something about my project. 2012 at 9:57 pm more useful to me.i want to see the full write up of the simple emergency light circuit pradeep says: March 6.7v. 2012 at 9:21 am Hi Prasad sorry not addressing your name. 2012 at 9:20 pm sir please tell ur mail id. it was made using 8 bataries 4 in series and parallel connection. pradeep says: March 6. Maximum of how many LEDS can be connected in this circuit to get high brightness and good battery back up. can you help me to arrange an Automatic LED Emergency Circuit for me.com/automatic-led-emergency-light 6/31 . 2012 at 7:51 pm Hi sir you replied for my question like below— Hi just buy a solar panel capable of 500mA at 12 volts.i want to contact with you vaideesh says: March 8. If you donot want the facility you can do away with R15 an switch with LEDs.circuitstoday. 2012 at 12:24 am Hi sir.. Seetharaman says: March 1.. 2012 at 2:28 am Hi prasad it is required for the light to come on automatically. raju says: March 30. 2012 at 9:34 am Hi Prasad you can use 24LEDs for a bright and long time lighting.Nice Design.2200 mAh samsung li-ion battaries..M says: March 2.5/12/12 Automatic LED Emergency Light Circuit April 9. www. The 11watts energy saver light and it will give you 7hrs non stop with fully charged battery. Prasad. connect it through a scottky diode(2N5819 or similar)to LM317 input by deleting X1. 2012 at 4:52 pm Really like the Auto Emergency Light. 2012 at 8:15 am Hi Vivek my contact mail id
[email protected] AH laptop batery. it suits both the questions you can use solar cell of the capacity indicated.M says: March 5. This will bec ome a solar light (charging the battery with solar energy and use it as lantern during night whenever required) Prasad. how to charge the battary? i want this to use it for the emergency lamp. D1 to D4.com vivek says: March 10. use one more BD140 in parallel (base and emitter in parallel)and to its collector connect another group of 12 LEDs.I Like!!! seetharaman says: March 12. 2012 at 9:18 pm sir i need the charger circuit for 14. 2012 at 6:27 am pis sir i need full description about the above circuit diagram samuel m koroma says: March 7. 2012 at 12:39 am i do not electric & electronic knowledge but when i saw this article i’m interested to do so. i can pay you. 2012 at 9:40 pm please sir. can u help me to do the same charger without a transformer and also protection of battery against over charging in it? David Colin says: February 10. we need to use an off the shelf 12V 1W lamp and so need to increase the battery size 2. 2012 at 12:22 pm I do not understand 1 emergecy light circuit. D1 to D4. Hi Kumar just buy a solar panel capable of 500mA at 12 volts.5/12/12 Automatic LED Emergency Light Circuit Prasad. Email: prasadm1987@gmail. av been searching for a v. 2012 at 6:38 am Hello sir. I have doubt so clarify me plz. Muhammad Ali says: January 12.Please explain me Muhammad Ali says: January 12. 2012 at 8:46 am Hello sir I have a requirement for the above emergency light circuit but with the following alterations. This is an additional protection against over voltage. LDR is used for switching off the LEDs during d available from other sources. please explain sir…. Seetharaman says: February 29. please explain the working of circuit no. Hi Edgardo thanks and I am back to India. rubel dhiman. 2012 at 7:27 pm i need an assist toward my project in the constrution of a low cost-automatic emergency light.i am little confused with working of transistors and lm317. shrikant says: February 3. connect it through a scottky diode(2N5819 or similar)to LM317 input by deleting X1. 1. with very low drop in voltage.com Kumar says: February 28. If its replied for me then should i retain R15 resistor and T2 BD140 transistor in the circuit or not.M says: March 1. Prasad. Can you advise what changes would need to be made please seetharaman says: February 5. 2012 at 10:10 pm Hi Shrikant no need for any calculation you can just go ahead constructing. Mosfet is used for switching the LEDs.. or directly we connect it given in the ckt diagram Seetharaman says: January 14.M says: February 28. connect it through a scottky diode(2N5819 or similar)to LM317 input by deleting X1. 2012 at 9:10 am 1) there is need of calculation for power supply. 2012 at 9:44 pm Hi I need to do Automatic LED Emergency Light using Solar power. 2012 at 1:27 am Was this replied for my question or not.2k and 16k 5watt resistor and i cn’t get it pls can their be mentioned or wherelse can i get it www. Please suggest necessary changes and modified circuit for Solar Emergency LED lamp with good brightness. 2012 at 12:18 pm Hi tony says: January 9. D1 to D4.circuitstoday.com/automatic-led-emergency-light 7/31 . 2012 at 10:31 am Hi Kumar just buy a solar panel capable of 500mA at 12 volts. 2012 at 5:18 am Hi Ali In the first circuit 7808 is the regulator for the charger circuit. In the second circuit 317 is the regulator for charging circuit and BD140 transistor is the LED driver.resistor 2. we would like to see a “charging” indicator LED to confirm the mains are on. 2012 at 9:04 am hi sir…………. Hi Rubel LM317 is a constant voltage regulator to protect the battery against over charge once the terminal vol will bring down the voltage through zener ZD1 and T1.2……. Rubel Dhiman says: February 4. It has no transformer. Afteral for Rs140/. may be in 6 months you have to go for a new battery. says: November 10.that is all you can expect from Chinese.minimum back up time 8 hours…. 2011 at 9:40 am this circuit is outdated. but when battery goes under voltage then also led remains on and damages battery performance by deep discharging Seetharaman says: November 10. nitin says: December 8. All these were taken care during the design. 2 capacitors. one Transistor. Good day and advance HAPPY NEW TO YOU.3 volt hence no conduction LEDs are not glowing plug emergency light to mains for charging. 2011 at 10:59 am hi. and what value also for ZD1 rechargeable batteries.6 volts Nicad rechargeable battery I will charge. ERRATA. 2011 at 5:13 am sir. And maybe I could make use of this circuit for my interne router requiring 5VDC. V. These get into India market due to our greedy t Ramasami.com/automatic-led-emergency-light 8/31 . just for flexibility on use of this circuit.8 volt (In charging condition) ii)Battery is maximum charged up to 6volt. of course I will connect a 5V regulator (LM7805) from battery B+ going to the router powe Can this be ok? Best Regards Edgardo Priyaranjan says: December 30. very simple. 2011 at 5:47 pm Hi Nitin refer the modified drawing it has got the low voltage cut off also.But I have two problems after completing the circuit i)Red LED is not glowing even the battery voltage is 5. It uses a 2+2=4v bty. 1 indicator red Led. 2011 at 8:58 am Hello Seetharaman. 1A supply. all LEDs are turn on when i plugged the mains supply. for the circuit Automatic LED Emergency Circuit Diagram. 2011 at 3:38 am Dear Sir. It works in AC 220v. ankit sharma says: December 28. 2011 at 8:59 am Sorry. HAPPY NEW YEAR inadvance to you Edgardo Edgardo says: December 30. I followed the modified circuit. Thanks. i assembled the automatic LED emergency light but there occurs a problem . switching of this ckt depends on mains power. My inquiry is this.5/12/12 Automatic LED Emergency Light Circuit Edgardo says: December 30. I need a led based emergency light with 12v battery. 2011 at 9:38 am what are the apparatus of this circuit sasi says: December 9. There is a switch by which we can manually operate it. It can auto switch when mains fail. regarding the simple version as there are 2 3volt LEDs in series they will not glow ar 5. Available o the above circuit all are taken care.circuitstoday. which is not available in India at present. IC LEDs. These products cannot enter USA market. You connect to supply for 24hrs and keep it away. I like this circuit. www. Use the light once the LED brightness comes down charge it over night and disconn the battery will get over charged and the battery life will come down drastically. 2011 at 3:00 am Dear SitaRaman. 4 resistors and 6 diodes.plz help sir Seetharaman says: December 19. what value of ZD1 I will connect in the case of 9.7k POT.please post some circuits it’s very useful…. I opened it. Please help. laxman says: December 19.I modified the circuit with 4. 2011 at 12:16 pm Hi Ramasami it is a LEAD Acid Gel cell of 4 volts. The Chinese made emergency lamp failed.. thank you sir. For LM317 see the datasheet on net. http://www.pdf Hi Paras you can use for blinker standard amber 5mm LEDs 5nos in series with 20mA constant current source using simple 2 transistors.com/ds/LM/LM117.(i need to tell the shop owner the ratings.0 volts at 2amps. if you have any old defunct one at home use its en materials from inside. hari says: October 27..but i would like to try this one(automatic led lamp) out.how do i find the polarities of various components like lm317 etc 3. Thanks. be explained?? Light Activated Switch Circuit says: November 10. without battery connected. With 1/2 watts LEDs 8 LEDs (4 in series in each loop) will work for 20hrs non stop. the total cost will be less than Rs500/. i got 12V 7 Ah Battery …… So please explain the circuit changes… how many leds(1/2W) are used for 7Ah battery…? plz help me…. I want to make SERVO VOLTAGE STABILIZER (SOLID STATE DESIGN) for my university project. 2011 at 2:42 am [. If you are using LM317 circuit adjust outpur voltage for 5volts at battery terminal end. 2011 at 6:08 am Hi Umer if you are using Simple emrgengy lamp circuit change 7808 regulator to 7806 regulator no other change is required.national. you need a major design change.2volts Umer says: November 2. for lm317 see the following link.kindly mail me answers of the following queries 1. 2011 at 9:15 am i got 12V 7A battery so can any one pls modify this circuit for it and i need more bulbs too pls help me JAYARAM says: October 26.] Umer says: November 3. hari says: October 27. Automatic LED Emergency Light [.circuitstoday. 2011 at 10:45 pm Dear Sir.circuitstoday. If you have any thesis or any material then Please mail me I realy need this. seetharaman says: October 27.. reduce R16 to 12 ohms and reduce ZD1 to 4.] 2.. how do i rate the led’s. use 3 LEDs in series with 50mA constant current source. 2011 at 9:28 am Hello Seetharaman.7A lead-acid battery? seetharaman says: October 28.com/car-battery-charger appeared earlier in this column M Sikandar says: October 27.excluding box. For head lamp use super bright white LEDs 4pin volt. regards jv www.appropriate cost of each components.. if you get 3 volt LED driver ICs use them they SMPS can take wide range of in put voltage and drive high currents the most application. 2011 at 2:24 am I m using LM317 circuit. 2011 at 12:43 am sir how to modify charger circuit to charge a 4V 0.com/automatic-led-emergency-light 9/31 . 2011 at 12:46 pm Hi Jayaram ask for high Bright white LEDs.. is’nt ) 2. Seetharaman says: November 2. 2011 at 6:17 pm Hi Hari for 12volt 7AH attery you require an output of 14.5/12/12 Automatic LED Emergency Light Circuit Can that cct. 2011 at 12:59 am i am not an electronics engineer.i don’t have any idea of selecting led’s for the circuit. You can use the charger http://www. how to reduce 7volt.If power fail go to battery mode. But most of the LED switching off can be done through some timer ICs?. 2011 at 10:36 pm sir. the emergency light goes on with full power when main power fails (LDR function will of course work) and remains till power returns.circuitstoday.5v. syed says: August 18.But I like to have some modifications. 2011 at 9:44 pm www. Benifit – usually the Emergency lights switch on always when power fails. 2011 at 4:26 am HELLO SIR.& also give me the details of material requires…. now switch to full bright mode. all LEDs) by some switch (pull to?) This happen only if there is inhabitant or through PIR sensors!. 2011 at 12:36 am got an idea to repair my own light. we should be able to switch on the same (main. we offanly see this types of lights r now used in forein countries…. 2011 at 12:43 am Hi Amit if you have 12volt 5Amp transformer. all LED’s. 2011 at 10:06 am Add one more 1N4007 diode in series with the existing 2 diodes. This full LED re-lighting has to be linked to auto switch off on power resuming. When ever you go out once you return locating light will not be a problem as it is already lit.. I want 24volt/10amps smps circuit with battery(half an hour backup). Can you suggest?. In the circut. I know linking PIR sensor is bit complicated. After the main LEDs got switched off after 1 or 2 minutes of power failure. amit kumar dev says: May 19. Yours is a wonderful circuit. I am basically a medical doctor but with a strong hobby in electronics Seetharaman says: May 21. 2011 at 10:48 pm Hello sir. use two 5403 rectifiers and a 3. with LEDs… plz help me to design circuit…. this may be due to the 7808 IC.pls reply me.Syed Babu seetharaman says: August 20.com/automatic-led-emergency-light 10/31 . Thanks & Regards S. Bhoopesh says: June 22. the Emergency light should switch on at full power. Abul Hossain says: August 9. This can be carried out through a switch. seetharaman says: June 23.5/12/12 Automatic LED Emergency Light Circuit Paras says: October 23. Modification I like – On main power failure.pls send me circuit as soon as possible. connect only 2 LEDs in normal mode (low light mode) and connect all LEDs for high brightness. 2011 at 7:36 am Hi Seetharaman. battery charging volt is 7. My suggestion will over come this. and stay lit till power returns – even if no one at home/even if everyone is sleeping!. 2011 at 5:06 am Hi Bhoopesh good idea. 2011 at 10:55 am This Is a Interesting and Practical Circuit that is useful to have around the House Even If You aren’t Crazy about Building Stuff!! syed says: September 2. RICK says: October 19.3 ohms 20watts resistance in series to limit the current to charge the battery. this my project .. expect 1 or 2 LED in there be LDR function included). Can you give some suggestions? And about me. But after a while – say after 1 minuter or 2. I want to modify my kinetic honda’s blinkers & tail lamps. almost all LED’s should switch off. I hope u will reply me soon.? Seetharaman says: April 14.? I did correctly. left as emitter. 2011 at 5:51 pm One more doubt…I am basically new to electronics.i have 5 amp transformer. shorting the collector and base makes the LEDs glow when connected to the mains. Thank you Seetharaman says: April 23.5Ah range.i think its my bad luck that it is also not av transistors that can be replaced in the place of BD140. Its nt available in any of the shopes in my area. Do I need to change the variable resistor to 4.5/12/12 Automatic LED Emergency Light Circuit hi its amit. when i connected to main power supply. 2011 at 12:03 am how to get reports in u r site telme thx Gaurav Jindal says: April 22. 2011 at 12:02 am circut of emergency light with ac 220v regience use not use transformer ok reply plz thx Roshan says: April 14. How did you do that.org/datasheet2/f/0c695lq7ut3hjriqzff0kfs5i8wy. I also tried for 2N2905. go throug http://www. 2011 at 12:51 am Hi Roshan I forgot to tell you for BD140 center collector right is base and left is emitter . What is wrong…? Roshan says: April 13. i modified the circuit as on your comment. You have said that you had to forward bias the transistor T2. it wont glow..wt more other devices are required to build its charger. But what happens now is. 2011 at 9:49 pm its good project for my edc… Seetharaman says: April 28.pdf Roshan says: April 13.i have a yb5l lead acid battery used in bikes of 12v.or how can it be charged using ho soon.7k.I took. if i short BD140′s emitter and collector. Did you replace the 1K resistor purpose? Roshan says: www. 2011 at 1:04 am Sorry Seetharaman.circuitstoday. I got all the parts expect BD140.datasheetcatalog. I would like to try this circuit. which is BD140. jojo says: April 23. even if i short those terminals. 2011 at 11:15 pm hey there. aswin says: April 27. Gaurav Jindal says: April 22. Otherwise it will be off. 2011 at 2:12 am Hi Aswin you can use 8550 instead of BD140. ot remove from mains. center one as collector and the right most one as base… Do you have the pcb layout of the modified version of the circuit.com/automatic-led-emergency-light 11/31 . 2011 at 11:24 pm hello Seetharaman. kindly correct it it will become alright. 2011 at 7:58 am Hi Roshan kindly inform me which circuit you are following so that i can give my comment.i want to use it as inverter fahad irfan awan says: May 12. This is just different from other plastic transistors. 2011 at 1:08 am What reports ? please explain your needs. the leds glow. 2011 at 7:43 pm sir. 2010 at 2:13 am Hi Sandy Go ahead constructing the modified version. But if I short the 1&2 or 2&3 terminars of BD140. Is there something wrong.com/automatic-led-emergency-light 12/31 . sandy says: December 12. 2011 at 12:06 am This is good circuit. you have referred to a ‘common negative’ . But didn’t work. use a good heat sink for LM317 as it has to dissipate extra 3 watts. the led 2) After the first time. i want to add a buzzer which will make sound whenever current is going and coming(like an inveter). 2011 at 5:11 am Hi Seetharaman. Seetharaman says: March 29. I have tried this circuit. choose ZD1 as close to 6.. we will try to build a few samples for evaluation. I need all ur help to complete successfully www. Please help me correct it. if i connect the main power supply. Following are the status of my circuit:- 1) after assembling the circuit and connecting the battery. Please help. 2010 at 6:05 pm hey dude thanks i may start asap Seetharaman says: December 13.Please give a repley Seetharaman says: January 4. 2011 at 5:36 pm Hello Seetharaman. but.circuitstoday. the leds are still off even after disconnecting from the mains. 2011 at 4:55 am Can I use 12-01-12 1A transformer for the 6V 4.2009. 2011 at 8:51 am Hello. 4) When I checked the voltage across ‘anode of D1 and R15′ or ‘cathode of diode D3 and R15′. 3) I dont know whether the battery is charging or not.com/automatic-led-emergency-light-modified-version Roshan says: April 13. Please Help me!! neenu says: January 15. you are sure to suceed.circuitstoday. the leds turn off.5/12/12 Automatic LED Emergency Light Circuit April 13. 2011 at 8:18 am Hi Ravi you can use 12-0-12 1Amp. the leds glow. 2011 at 4:28 am I want a circuit to illuminate a lamb and if cut off it switchs another lamb autumatically enersystec says: February 18. Ravi says: January 4.8volt as possible. Adel says: March 29. 2011 at 8:56 am Hi Imran you can use 2N2905 or the recent 8550 transistor. IMRAN says: January 29. I don’t know why. the voltage shown in the multimeter is very low.Is that the common ground of the ‘lamp section’? Seetharaman says: April 13. But shorting the terminals of the BD140 turns it on. Can I replace BD140 PNP transistor with any other transistor? I didnot find this in my local market. 2011 at 9:55 am Hi Roshan kindly refer to my comment of Dec 27th 2009 and also refer to my modified emergency light appeared in circuits today http://www. In the comment of December 29. thanks for the quick reply.5Ah SLA Battery? sandy says: December 14. 2010 at 8:51 pm hi friends this sis sandeep i am planning to start this project on my own. I made this circuit. Thanks for the help shreya says: August 22.com/automatic-led-emergency-light 13/31 . Pls respond.com/automatic-led-emergency-light-modified-version Achin Jain says: November 8. please tell me what modifications are required for making this? tell me all changed resistors values. and also tell that.4 v. i need to glow more lights for more hours. if u could prepare a circuit which would house about 50 to 60 leds would really appreciate. 2010 at 10:04 am Respected sir. I am a student of engineering.circuitstoday.circuitstoday. 2010 at 9:15 am Hi seetharaman subject: 100watt sub-woofer i shorted R9 & R10 the temperature of transistors decreased but Q7 is getting hotter than Q5 why ? patrick vaz says: August 18. For good brightness use hi bright white LEDs.com Thank you rishaan says: November 8. Seetharaman says: September 19.5/12/12 Automatic LED Emergency Light Circuit Seetharaman says: November 9.with lead acid battery of 6v give light? plz reply soon. sir i want to know what exactly Automatic means in this project i mean what is the process of its charging and how the complete informations related to this circuit in detail sir i’ll be highly thanks full to you if you reply me for all of my queries and asks i want your support for it because this projects is ver please reply me on my mail address i. i need wattage of all the resistors used in the circuit.com/automatic-led-emergency-light-modified-version#ixzz0wy4MjNUk Under Creative Commons License: Attribution deepak says: August 17. if you fell it is not then add one more BD140 with 12 more LEDs with will be equivallent or better than 11 patrick vaz says: September 19..i want to make this circuit with 24 led’s. 2010 at 4:15 am thank you for the reply.circuitstoday. 4Ah li-ion rechargeable battery.tell atleast the lighting circuit. 2010 at 6:30 am HI. 3rd year sir i was going through with the circuit diagram and wanted to work on it. 2010 at 9:40 am Hi Patrick no modofication is required you can use12 volt 500mA transformer and 6 volt 4AH battery. pradeep says: August 6. pradeep says: August 6. 2010 at 5:50 am Hi Admin. 2010 at 3:01 am hi sir…. 2010 at 1:06 am Hi Jain you go through the modified version of this you get the full details including calculations http://www. but the Brightness is very poor. 2010 at 9:27 am Sir. Read more: http://www. 2010 at 8:59 am Hi seetharaman subject: 100watt sub-woofer www.e
[email protected] would like to know how much does constructing this full project roughly cost? because im planning on doing this project as a low cost product… abhishek says: September 23. Normally 12 LEDs are sufficient. 2010 at 7:32 am i want to know how it will stop charging after full charge?? please write how voltage changes and all that for working of this ckt. shreya says: August 4. I Have a 0-12V transormer 500ma and the battery is 6v 4ah will any modification be required in the circuit. 2010 at 4:18 am i am having 14. 2010 at 2:53 am waterlevel alarm seetharaman says: August 3. 2010 at 11:36 pm how much time it will works when battery is fully charged? seetharaman says: July 23. 2010 at 10:07 am Hi Pradeep around 10 to 12 hrs. instead of 12 hrs it may charge in 8hrs or so. 2010 at 7:16 am can i use 6v 9AH battery for the circuit? what are the things i should change? in the above circuit what is the wattage of resistance used? what will be the power output of the circuit? seetharaman says: July 29.5 X 16 that is 4watts dissipation so higher wattage is preferred hence 5w wattage resistance less than 4 watts it will get cooked up. geetha says: July 23. That is 300 mA the lamp may work for a maximum of 2hours only.5 amp rating. 2010 at 7:45 am yes it will improve. think of solar rec Sunny says: August 2. So i want to make a LED LAMP which i want to light up from a dry battery. 2010 at 7:09 am why we use the 5W resistor?what will the effect by using high wattage rating of resistor? seetharaman says: July 26. 2010 at 5:57 am if i use 1amp transformer will the battery get charge quickly?? seetharaman says: July 25.in my village there is too much problem of light.5/12/12 Automatic LED Emergency Light Circuit i shorted R9 & R10 the temperature of transistors decreased but Q7 is getting hotter than Q5 why ? logeshwaran says: August 4. adnan says: July 26. pradeep says: July 31. seetharaman says: August 1. Normally the high bright white LED requires around 25mA at 6nos LEDs for enough brightness to read using as a table lamp. 2010 at 1:23 am got an idea to repair my own light adnan says: July 21.5 X 0. 2010 at 11:17 am can i use 9-0 v 1A transformer for the above circuit???? adnan says: July 21. think of alkaline cells quite expensive. 2010 at 3:45 am Hi Pradeep you can use but the charging circuit has to be modified. will work for 10hours.circuitstoday. That is if you draw 50mA from it. A power transistor to be added to LM317 IC as it can handle a m to be changed to 2 ohms 20watts. 2010 at 9:57 am Hi Adnan you can use.5amp is flowing through 16 ohms resistance then the power dissipation by that resistance is Isq X r = 0. 2010 at 8:45 am If 0. Because in night we have much diffculty in studying by usin tell us how to make led-lamp by Buying what materials from market.com/automatic-led-emergency-light 14/31 . 2010 at 3:56 am Hi Sunny You can use D size torch cells will give you 500mA hour. The transformer to be replaced with 2. adnan says: July 29. 2010 at 11:17 am www. pradeep says: July 24. 2010 at 7:15 am Sir. you have to use a charger suitable for the battery. 2010 at 5:35 am we are using 7ah battery seetharaman says: June 26.I’m asking this kind familiar with electronics since i’m an IT student. 2010 at 11:12 am can i use 9-0 1A transformer for the above same circuit??? seetharaman says: July 19. saravanan says: June 28. www. normally lead acid cells should work for 500 charge discharge cycles.Sir.it working inverter mode only 10 miniutes and then cut off automatically.we are seperately installed 50w inverter ( output 1) 230v ac 2)12v dc ) .Can we use mains for charging as well as lighting purpose simultaneously?. that is 7. seetharaman says: June 15. 2010 at 10:30 pm Dear Saravanan You can use a battery which can sustain for the required hours (battaery AH capacity) say in your case the battery is 12volt and watts is 50 if the inverter efficiency is say 80% you require battery is required.25 amp will take a very lon g time to get charged.35 ampere current to a 4.it will be cut off after 10 minits ( if power cut inverter mode is on ) seetharaman says: June 16. actually i confusing at bd140 transister i.m not getting output from bd140 why? i tried as like the same above circuit onlr bt i didn’t getting outpu connect the bd140 circuit.But i like to do in electronics section.customer was very un satisfied. 2010 at 5:21 am i want automatic cut off circuit for 50w inverter. 2010 at 11:14 am if i give more than 1. 2010 at 6:37 pm i am working in mnc company.. kindly refer modified circuit of this.main is on normal working cotinusely on.5 amp charger. For R16 you may use 4. Check whether the built charger is capable of charging at the rate of max 2.5/12/12 Automatic LED Emergency Light Circuit can i use 9-0 1A transformer for the above circuit???? adnan says: July 21. saravanan says: June 25. 2010 at 6:07 pm Thank you sir for your kind reply. 2010 at 2:44 am Hi Aji yes you can use. Try the above checks and give a feed back for the solution. AJI says: June 15. i’ve tried this circuit bt i didn’t get result. 2010 at 3:44 am Hi Aji you can use 2200uF. 2010 at 1:24 am the battery will get heated up and it cycle life will come down drastically. by the flip of the switch the light will glow during charging. as the built in charger of the inverter will n saravanan says: June 26.com/automatic-led-emergency-light 15/31 . 2010 at 8:05 am Dear Saravanan with 7AH battery it should work for 45 mts to 1hr. if cotinues working 1 hour battery is try. mahesh says: June 16. ligh will back up 20 miniuts. adnan says: July 18. plase give modulation circuit for above problem. Hi Mahesh modify your circuit as per the modified version it will work. say for 5hrs you require 25AH battery is required. Check with a fully charged battery.I’m very honoured to hear from a great person like you. 2010 at 12:06 am hi. 2010 at 11:16 am can i use 9-0 1A transformer for the above circuit adnan says: July 21. if power will come operation. and charging above manu and deep discharging the batteries will get their life shortened.7 or 5 ohms resistance 5 watts so that the battery charges within 12 hrs from discharged level. Automatic LED Emergency Light Modified.circuitstoday. by over charging. connect the base of BD140 through a 220 ohms resistance to negative by using a switch. if power is cut the inverter mode is on.5AH battery what will happen??? Seetharaman says: June 28. 2010 at 2:44 am Hi Tutul yes charge completed and under voltage cut off is also included in the modified version refer the following page http://www. John Faraz Khan says: May 23.what could be the problem sir? Please give me a solution and circuit diagram if possible. Another question i want to ask that i want some leds about 36 in number. I know about the BD140 that it will not handle the current so i gue parallel to the first one. Thanking you sir. from each BD140 base you connect one no. this will enable all the three BD140 to share the current equally.i tried to make this circuit. 2010 at 1:34 am Hi Faraz Khan Can you give the full DC side requirement. 2010 at 6:47 am I want these requirements 1) DC Output 2) 0 to 45 and -45 to 0 Volts 3) 5A on both channels 4) It must be transformerless. That is connect all the three BD140 emitters together. whether regulated what is the voltage etc.com/automatic-led-emergency-light 16/31 . seetharaman says: June 7.com/automatic-led-emergency-light-modified-version/comment-page-1 TUTUL says: June 6.circuitstoday. seetharaman says: May 25.circuitstoday. 2010 at 4:13 am Hi Seetharaman So i just have to place 680 ohms resistors in between each base of BD140s and leds circuit to individual collectors..Whether this problems affect my circuit Please reply. I have one CFL emergency light of “Champion make”. 2010 at 12:47 am Hi Faraz Khan You can use 3 circuits of 12 leds driven by its own BD140.5/12/12 Automatic LED Emergency Light Circuit Aji says: June 14. Faraz Khan says: May 16. when mains sup not “cutoff” automatically. collector through 12LED in negative as the above circuit. 680 ohms to negative rail. I’ll check it. john says: May 24.My problem is that. Faraz Khan says: May 15. With regards. which will make current divide. I want to make a transformerless power supply for my projects. 2010 at 9:08 am Hi John one D882 is for invertor and the other one is for voltage regulator for charging the battery. seetharaman says: May 23. I want a supply that can provide me 3A currents both in positive volts searched all supplies which uses a transformer but those transformers are quite expensive. 2010 at 11:56 am Hey Thanks SEETHARAMAN.Resistor with 16ohm resistance is not available to me…Is th these. C9012 & 14 are for auto operation you may check these transtors they are PNP and N on all these transistors. base through 680 ohms from each BD140 base to -ve ra BD140 collector. 2010 at 2:59 am Hi Faraz Khan R15 you reduce to 680 ohms. 2010 at 5:14 pm Sir. This utilizes 2nos of D882. 2010 at 8:40 am Hi Guys i want to know that how can i request here. Is it correct? seetharaman says: May 16..I have got 2200uF capacitor instead of 1000uF. seetharaman says: May 17. 2010 at 5:50 pm hi guys. 2010 at 7:00 pm sir do you includ low voltege discannect circuit? please reply. Is it OK? www. Faraz Khan says: May 22.1no of C9012 and 1no of C9014 transisitors and other components.But there are many problems with my circuit. accordingly. emitter of all BD 140 to positive supply. Two mails sent to your above id failed to deliver. I want to insert a buzzer alarm in the circuit. i want the buzzer.Seetharaman. seetharaman says: May 8.7volt). 2010 at 9:20 pm This circuit to good & working fine. V GOPALAKRISHNA. 2010 at 9:37 pm Dear Seetharaman. P is for full plastic package and pins as per T. 2010 at 2:41 am hi devang you email me i will reply you in depth.. the charger circuit need not used. D2T is SMD package. 2010 at 11:58 pm NOTE: Considering the doubts raised by many of our valuable readers in our Comments section. K is TO3 package similar to 2N3055. If you have any simple inverter circuit please share. Faraz Khan says: May 15. any way i will mail you in your id. 2010 at 5:40 pm Dear Seetharaman.com and also kilndly send the prototype develope LEDs for the LED light through Mains. devang manseta says: May 3. 2010 at 1:08 pm hey can any one explain me tha working of thid circuit? Mr.7 across the sounder add a sounder to block negative voltage. You here: http://www. Rgds. alarm me every time the battery get full charge. one of our valuable contributors.circuitstoday. But with the present design. this circuit has been modified by Mr. i have already devoloped few circuits with pcb etc which are in use.Kindly send the modified circuit to me also at vgkmig1588@yahoo. 2010 at 8:51 am Hi Faraz Khan use an electronic sounder (phezo electric) in parallel with diode D5. At every alarm signal i will switch off the ac main for Power Saving. If dont want negative voltage of 0. if you use amber LEDs you can use two of them in series.com/automatic-led-emergency-light 17/31 . Is it possible to connect CFL lamp? How to hook up inverter circuit to this circuit? please let me know. When the battery is getting charged the sounde around 0. +ve of the sounder to cathode and -ve to anode of D5. Regards and Thanks. 2010 at 9:50 pm Hi Colin yes i agree with you.com/automatic-led-emergency-light-modified-version seetharaman says: May 4. once the battery is fully charged T1 switches on the battery will supply sounder around 4 volt for it to sound. Mails are bouncing back from your ID.com… Also please send me any LED lights working we can save energy a lot if we can replace our existing ‘bulb’ with these LED leights. it can be used. john says: May 4. Regards. so please let me know any other id or send the circuit to my email id –
[email protected]/12/12 Automatic LED Emergency Light Circuit seetharaman says: May 15.2volt connecting the charge of the battery. i have plans to submit soon to Circuits Today for Hi prshanth the standard emergency light PCBs are available in the market using 7/11Watts 2 pin energy saver tube with 6 volt gel cells. 2010 at 11:54 pm My id is seethasub@hotmail. Anand Prashanth says: May 2. with white LEDs the voltage requirement is 3 to 3. www. If you use 4volt batteries the efficiency can be improved or 12 volt with 3 LEDs in series. Prashanth V G KRISHNA says: May 1.circuitstoday. Anand says: May 2. but with discharged battery may not glow at all. Every One. 2010 at 4:32 am Hi. Seetharaman says: April 30.anand please try seetharaman says: May 2. 2010 at 11:06 pm Hi Anand LM317 and T are the same in TO220 package.com. necoz im using 317T. Hyderabad.connecting 560 ohms resistance between the junction of D1 and R15 to common negative and reducing R16 to 4E7-5watts. No switches are provided in the original circuit. I assembled the above circuit. 2010 at 4:37 am Dear Seetharaman. i will recheck the same and get back to you if any help required. Thannx for ur suggesions. If you post or send the revised will help me a lot and also there wont be any confusion for me.. Anand Anand says: April 30. Regards. i need your help! please anyone who reads this and is aware of the problem please answer my question! i have tried the whole circuit leds glowing well but it glows even wen i switch off da mains i dont know wat to do? plz help n how do i rectify the batery is getting charged or not plz plz reply as soon as posssible! Anand says: April 30. seetharaman says: April 30. Thank you for your reply.LM217 LM217K LM217T . 2010 at 10:29 am hello. regards. collector through 470 ohms and an LED (I pre (BC148) emitter. connect its emitter to D5 R16 junction base through 100 ohms resistance to R16 ZD1 junction. To improve charging current as I have mentioned earlier reduce R16 to 4E7 5Watts. rgds. Anand devang manseta says: April 30. When ever there is a higher charging current through R18 the LED will glow brightly and as it tapers off LED will become dim. Anand says: April 30. Subsequently suggested earlier by you by reducing R15 to 560 ohms. India..circuitstoday. Thanks a lot to you. Now I request help from you. Regards. Upon light is coming within a fraction of second. pls let me know . 2010 at 12:17 pm Dear Seetharaman.. V G KRISHNA says: April 29.Gopalakrishna. So kindly suggest for the benefit of me as well as to all users as to. All the 12 LEDs are glowing alright when I swith off the mains but it was taking 5 to 6 seconds for the LEDs to light after the power switch off. Anand V G KRISHNA says: April 30. 2010 at 2:01 am Thankyou Seetharaman for your kind prompt reply.LM217D2T LM317 LM317K LM317T LM317P LM317D2T Hi Anand send me a email seethasu@hotmail. 2010 at 5:06 am Dear Seetharaman. You can reduce For charge indication use BC158 transistor.5/12/12 Automatic LED Emergency Light Circuit Type TO-3 TO-220 TO-220FP D2PAK LM117 LM117K . Could yuou please send me the revised circuits with necessary changes in the components value?? i want to assemle the same from begining in a new board. 2010 at 1:17 am Hi Krishna you can provide the switch between BD140 emitter and battery positive. V.com I will mail you my modified circuit. where to provide a switch for the emergency light portion to switch on/o www. 2010 at 12:51 pm Dear VG Krishna.. could you pls tell me wht is the difference in the pins of LM317 & LM 317T?? i found both are same in the net.com/automatic-led-emergency-light 18/31 . GOOD LUCK. Hyderabad. Kindly advise.5Volt Hence 0. All the 12 LEDs are glowing rich. thanks VG KRISHNA says: April 8. 2010 at 6:14 pm Hello Seetharaman i have tried the circuit and it work.GOPALAKRISHNA. I am a retired (finance) person having interest in electronic hobby projects. the designed circuit is meant for 6volt when we adopt it to 12 volt we have to modify the circuit according Masandhie says: April 19. Vbe forward bias will be 0. when I measured the voltage at the two terminals before connecting to the 6v 4ah battery. Anand says: April 24. unless i) we attach the 6V 4 ah. But two things what I observed are 1) the LED lights are not glowing based upon the supply from the transformer alone. with 7 loops (7 X 3 = 21 LEDs)The current will 7 X 25 175mA and the voltage drop a 11. it is still measuring/playing between zero and 0.the resistor will only get warm get very hot (i can put a fan on it but it will increase the battery life). If it is connected as forward biased diode only this can happen. Pls suggeste me wht will be the wrong. R15 is sufficient to limt Ibe.2v. battery in the circuit.0875 the transistor will be cool running. I want to increase the no. Overall the circuit is good. Thanks to ALL.5/12/12 Automatic LED Emergency Light Circuit keeping the set plugged on to mains on. For increase in the light. 2) It is taking a few seconds (5 to 7 seconds) to the LED lights to glow. I thank S who are participating in sharing the ideas with their expert advice. V.5Watts Hence BD140 will g will be wasting huge energy as heat. it has improved to DC V 5. But I found following problems 1) The output of LM317 can be set maximum up to 2. it was only 0. please check up the assembly of your circuit for any ‘short’ connections and for correct pins of the transisters 1 a for LM 317 and LM 317 T. Hope this will be suffcient to charge the battery. HYDERABAD.com/automatic-led-emergency-light 19/31 . making thus the circuit comlete. 3) I have connected 12 LEds and only 6 or 7 led’s are working and that also not bright. Where to provide an LED light to indicate that the set is under charge. over the switch off of the mains. 2010 at 1:23 am Hello Seetharaman.65 volt.87 DcV and a alterations. 2010 at 8:48 am Hi Figo Vbeo indicates the reverse break down voltage of the trasistor base emitter junction. For your problem.5A is 4. Further more I want to share with you that as per the original circuit. seetharaman says: April 25. India.5 X 0.Gopalakrishna. 2010 at 9:07 am Dear Anand. www. 2010 at 3:56 am Dear Seetharaman. 2010 at 8:58 am I salute Sri Seetharaman for his expert and excellent advices being given by him. 20 led with 3 resistor 27ohm/5w to limit the current and it work. thanks Figo says: April 6. 2010 at 9:53 pm Hi Masandhie Since you are using 12volt with 20LEDs 20 X 25 is 500mA current and the voltage drop across the trasistor will be 12-3=9volt 9 X 0.Gopala krishna. I want more and more such Projects. By reversing the zener will solve all your problems. if it is made to glow when power is available (work as a night lamp) and auto changeover to Battery in case power goes. 2010 at 10:25 pm Hi Anand Please check the polarity of the zener diode. Instead use 3 leds in series with 100 ohms resistance in series. which I have seen from many a circuits. V. as suggested by Sri Seetharaman abaove. I assembled the above circuit and am happy on the success of it. I tried this circuit exactly what you mentioned in the Circuit. V G KRISHNA says: April 24. I think. this can be improved upon based upon the improvements suggested by Sr 2009 above.94 v by adjusting the potentiometer. Thanks to CIRCUITS TODAY. seetharaman says: April 19. can the BD140 changed with other series of transistor which has higher output current?and if it can what series do i had to applied? i have tried some series like TIP2955 or 3055 but it fail. I am getting the maximum voltage pas 6.I have assembled about two LED circuits which are working excellent. India. regarding protection You may Admn to publish it bu which all will be benefitted. seetharaman says: April 6.and ii) only after will be convenient. V.2k is adjusted to maximum by me. The preset 2.20 but when I mesured the DC amps with multimeter set under DC 10 Ah. INDIA.01. I am at loss to unders charge the 6V 4 Ah battery.Hyderabad. in my experiment i use motorcycle 12v lead acid battery. Through these columns. of LEDs also .5=0. I am verymuch interested in the circuit and Thanks to CIRCUITSTODAY for providing the circuit. 2) Out put voltage of the battery charging end shows Zero.circuitstoday.175A = 0. I will request Adm Circuits meet your requirement. I will try.{ fault in LM317(short)}. By the way is it work if I replace present charging part of the circuit with Ni-MH charger (i mean can i still use BD140 if I replace the charging part of the circuit). but I do not know how to share this circuit here. How much current required or what energy they consume.But what be the possible wattage of this circuit. I don’t want to use 6v 4. elex says: April 2.5AH lead acid gel ce voltage and initial current <30%). 2010 at 1:50 am Hello Seetharaman. I mean when LEDs are on. Shenzhen is not only a Battery city. Let me check the circuit again and to see how to improve this circuit to make it perfected. Incase of bulb I don’t have a chanc Thanks and Regards Samba Damerla seetharaman says: March 26. 2450 mAmp AA rechargeable cell.8Volt and the max charge current is <30%. please also share with us here. Its fine if we reduce number of LED’s to six.5/12/12 Automatic LED Emergency Light Circuit I have two comments on this circuit. Samba Damerla says: March 30. Please advice me how can i change the circuit. Samba Damerla says: March 28. 2010 at 3:53 am Hi Samba for Nicad or NiMH batteries constant current charging is important and NiMH cannot be trickled successfully even at 1/40 th of rated current for 40 hrs. Its ok if we reduce number of LED’s to 6. god blis elex Samba Damerla says: March 31. so we need add a 9V zener from base of T2 to GND. you can use Ni-MH battery charger using LT4060 appeared in Circuits today.com/automatic-led-emergency-light 20/31 . www.circuitstoday. 2010 at 5:41 am Thanks SeethaRaman. 2010 at 5:57 am Hi Seetharaman. Please tell me how to change the circuit. 2010 at 6:27 pm Dear. 6 volt 4. if you have any good ideal.5 V. I want this because I want to setup this as buld and sit in a bulb holder. In my mind. The Vebo of T2 is 5V. A good project. Lots of modifications are required to the present circuit. it seems required a voltage comparator to detect the battery voltage. 2. Thanks Samba Damerla Figo says: March 29. an additional sensing circuit to be provided to cut off the load. Charging is taken care. looks like you are also a professional guy in electronics design. Thanks & Regards Samba Damerla seetharaman says: March 30. the terminal voltage is limited to 6. I will add my comments here. If possible could you please let me know once Adm Circuits publish a circuit for my requirements. Thanks for your quick response. charging NiMH are co are available in the net. 1.25volt is end point of 6 volt battery(infact no useful energy is available below this from the battery discharge should be cut off(load should be cut off). you may also suggest your improvement in the circuit.5 AH lead acid cell. I want use 4AA 1. I will search Ni-MH charger circuits. Thaks for your critical view. 2010 at 3:23 am Hi Figo from the Battery city. I have a sketch of discharge circuit to protect the battery.5 V 2500mA rechargeable cell instead of Acid battery. instead of that I want to use four 1. only discharge is not taken care yes voltage less than 5. hehe. I want this change to make a rechargeable torch or a rechargeable bulb (which can sit in a bulb holder). 2010 at 2:21 am Hi Seetharaman. hence T2 will no of LEDs. seetharaman says: March 20. seetharaman says: March 17. that is from BD140. Im very interesting in this circuit. becoz different battery has different charging character.circuitstoday. LED1 to 12 and R3 to R14. the present battery with 4.(T2. 2010 at 1:36 am Hi SEETHARAMAN. 2010 at 5:23 am Hi Masandhie Sorry I have missed. but I have some concerns: 1. 2010 at 2:24 am Hi Lucky you can add similar circuits (with R15.com/automatic-led-emergency-light 21/31 . riddick says: www. Due to manufacturing spread the LED with least resistance will try to pass high current since no limitation limit the current through individual LEDs (safe limit of 25mA each in this case)when connected in parallel. does it function to limit the charging to battery?is it necessary to change the zener diode with the higher value? seetharaman says: March 25. 2010 at 8:25 pm Hi Lucky Kindly check T2. because i built it but it does not works automatic. Seetharaman. Also hope we have more discussion here with guys in the world. So that you can drive 72 LEDs. You can use 3 LEDs in series in each loop(total of 36LEDs).5/12/12 Automatic LED Emergency Light Circuit Figo says: March 25. Ni-Cd or other type of battery.5AH capacity. Can you send me a 70 LEDs circuit configuration.com/#calc will help lucky says: March 21.8volt. For BD140 center collector left emitter and right base. During power on base will be more positive than emitter hence T2 gets reverse biased. How to limit the charging current to avoid damage to battery due to a higher chanrging current when some fault occured. 2010 at 12:19 am Hi Sathika you can add similar circuits in parallel. TR2. i check it. if i use a 12V lead acid battery that will flow to the Emitter of the T2 is it ok if i use a 15V input from my 1A transformer and can i change the ZD1 with 12V or 13V for charging the batte i try to use a 15ohm 5 watt to replace the r3…r14 wich will be connected paralel to my 25 LED…hopefully the current consumption will be 500mA maybe this http://ledcalc. 3. How to limit the discharging current to make the battery will not be damaged due to over-discharging? 2. Hope get your response soon.5watts) Masandhie says: March 25. What type of battery we can used on this circuit? such as Lead-acid battery. But the battery will last fo lucky says: March 20. You cannot paralllel all the LEDs and connect a common single resistance. then its glow and when suplly is disconnenect then its also glow… Why??? whats a problem seetharaman says: March 15. when supply ON. 36 LEDs will glow for more than 4 hrs non stop. LED1 to LED12 and their series resistances R3 to R14) 6 sets in parallel. Please do not forget the good heat sink for T2. This is Figo come from Shenzhen of China. set the voltage to 13. 2010 at 2:35 am its not a complete circuit. for each additional 12 LED the battery is also capable of handling the load. 2010 at 1:42 am Thanks. 12 LEDs and their current limitting resistances in series. 2010 at 10:33 pm Hello Admin. You ca ohms. 2010 at 2:28 am Hi Masandhie yes you can use 12 volt battery and replace with 12 to 15volts transformer. yes you have to increase it to 13 volt zener with the same wattage(0. Masandhie says: March 25. 2010 at 5:30 am Thanks a lot SEETHARAMAN that’s helps me a lot seetharaman says: March 25. 2010 at 7:47 am Thanks seetharam. Masandhie says: March 25. 2010 at 2:38 am What about the zener diode ZD1. lucky says: March 17. I bought few small led’s and one 3W PRO LIGHT LED( approx – 3$). I will test the charger with a battery in the next few days. I mean when LEDs are on. Planning to build few led projects to prepare for the power cuts in the coming su www. Modern emergency lighting is installed in virtually every commercial and high occupancy residential building. for 3 white modern leds (available in india)you require 3. Emergency lights are standard in new commercial and high buildings. i am using this circuit with my existing solar lantern with built in 7 watt energy saver tube’s battery supply.2 X 3 9. Arifuddin Sheik says: February 28. This circuit needs that protection of low voltage. I plan to build the led part.5AH battery you can have a minimum of 16 hrs non stop run. 4.com admin says: February 26. please suggest me vikas billa says: February 25. what should i change? It’s great diagram.it is really workin.But what be the possible wattage of this circuit.circuitstoday.so 80mA is drop across transistor. better set the open circuit voltage at charging terminal to 13. 2010 at 5:25 am How many hours of decent backup will we get using this circuit. 2010 at 11:25 pm Reply to Vikas Billa Current rating of Transformer X1 must be 2A. 2010 at 9:52 am Thanks Seetharaman for your quick reply.as it was our project finally we got good marks… ravinder says: February 1.5/12/12 Automatic LED Emergency Light Circuit March 5. But do we need any other changes apart from the LED current limiting re Arifuddin Sheik arifuddin2007@gmail. I have built only the charger part. I have few spare LEAD-ACID batteries and was looking for a circuit to charge those (6v.5 ah battery is enough. An emergency light is a battery-backed lighting device that comes on automatically when a building experiences a power outage. hence you will have a total of 48 LEDs glowing(lots of illumination)still with the same current consumption of appoximately 250mA. but appreciate if you can tell me how can i add more LEDs (30 or 40) in to this same circuit (With 6v battery). 2010 at 11:42 pm here in the above circuit they used 14 leds. but can’t see the facility with post reply section here.. All units have some sort of a reflector to focus and intensify the light they prod Sathika says: March 3.com/automatic-led-emergency-light 22/31 . You require a series r 12 Volt 4. 2010 at 9:43 am Hi you can use 3 LEDs in series. so pls explain how we can attach 3LEDs in series with same setup(anyway circuit is having 100ohm with 6v bat). The emergency lighting heads are usually either PAR 36 sealed beams or wedge base lamps.The ouput current from transformer is 500mA. I’m very very new to electronics & still i’m lerning. The lights consist of one or more incandescent bulbs or one or more clusters o diodes (LED). 2010 at 12:58 am After a long gap in electronics I have built this circuit. Seetharaman says: March 2. Next. this reply is for md arifuddin sheik’s quiery. the 4.6 volt which will be just correct for lead acid gel cell. the life of battery may decrease. Output voltage is 7v and the charging current is – 200ma.each led takes 30mA so 14*30mA=420mA. such as college dormitories. Sathika says: March 2. also. Now my question i have to connect 40 leds…so what will be the output current of my transformer . I will try. with 100 ohm curren voltage drop across transistor a 12 volt DC supply is required.6 volts at 25mA. We can increase the LM317 o/p to 13v. 2010 at 9:35 pm Hi sathika. Most building codes require that they be installed in older buildings as well.5 AH). 2010 at 7:00 am Hi SEETHARAMAN. 2010 at 1:45 am thanks for makin such a ckt….. How much current required or what energy they consume. yes it is for a 12volt supply. diode and variable Voltage regulator. 2010 at 10:37 pm A good project. 2010 at 11:34 pm hello i want to use 40 leds suggest the corrections in the circuit idris says: February 10.2V. If we use changes we have to make to R16. or are you planing to seetharaman says: March 1. If battery drains below 10. but back up time will be less. fit a small heat sink to BD140 vikas billa says: February 25.whether i have to change the battery. plz do help i need it for my final year project thanks pls e-mail to my inbox
[email protected] i connect the battery the 16 ohm resistace gets burnt the led blink for sometime and then it goes off the resistance gets b Thanks IFTIKHAR says: August 26. BC107.i will like to have more info n details based on AUTOMATIC EMERGENCY LIGHT.pl help THANKS mhanelle says: July 31. Will tranformer of 9v 500mA charger 12v battery? If not should 12v 1000ma transformer be used.. 2009 at 9:37 pm BC148. Am I correct? 2.com. 2N2222 etc gurmeet says: November 4. Yee shin says: October 21. want to know the function and work of each component used..com/automatic-led-emergency-light 23/31 ...I’m making the ckt now………….i do appreciate isaac says: November 17. cause I can buy this can something take place in this place ... By reducing R16 to 4E7 5 watt the charging could be improved to over night in m vivin says: December 16. BC107.i will like to have more info n details based on this project.i do appreciate admin says: November 13. can help me please …………. 2009 at 11:36 pm hello. what changes are required in circuit? 1.. want to know the function and work of each component used.com....... 2009 at 9:45 pm Good ckt but will you please give circuit diagram for same emergency light using npn transistor yeeshin says: October 4.. plz do help i need it for my fin pls e-mail to my inbox snowboy3k@yahoo. I have reduced R5 to 560 ohms and connecte between junction of D1 & R5 to common negative.. 2009 at 10:42 pm hi can i use the BC547 in the place of BC548 cause the store have not this BC548 Please Please I need to know .circuitstoday. 2009 at 9:36 pm BC548 can be replace with transistors like BC148. 2009 at 11:07 pm hello. 2009 at 10:28 pm what can use in the place of BC548 . How much time will be required to charge 12v battery? 3. 2009 at 9:23 am how to make emergency with maximum white led in a 6 volt batt isaac says: November 17. 2009 at 3:05 am hey friends plz help me I am having a problem with this circuit. To make the lamp work I have to forward bias transistor T2..can help me please I’m making this ckt now plz yee shin says: October 20. 2009 at 8:40 pm If I use 12v 9A battery. rohit mukherjee says: October 2. R3-R14 resistor should be 1k each. kunal says: October 7... 2009 at 7:07 am how much time will it need to fully charge befor it stop charging? www. Which made the LEDs come on when power failed.I’m making this now………………. 2009 at 2:34 am hello dears i want a similar circuit with 12v & simple bulb of 50w because i want much more light.5/12/12 Automatic LED Emergency Light Circuit Seetharaman says: December 29... 2009 at 8:48 pm what can use in the place of BC548 cause I can’t by this ... 2N2222 etc can be used instead of BC548 admin says: November 13.. 2009 at 2:37 am Thanks for the very useful domestic gadget during present days of power cuts. Kichler Lighting says: February 25.5K resistor. If the extra LED’s are connected in parallel to the original ones. The circuit was designed for 12 LED’s and not 24. in have several pnp transistors in stock. if a 12V supply is used. 2009 at 1:31 am i assembled this circuit and use 24 led 5mm but problem is that all leds became dim after a few seconds. if any one has suggestion. the chances are that your ba admin says: June 17.2K each. 2009 at 7:05 am how many hours will the battery last? twits4twats says: June 17.48A). 2009 at 4:39 am There is promble of charging of battery it takes 20-36 hrs hyla says: January 12. 2009 at 6:41 pm dEAR TAHIR CHAKE 2. 2009 at 12:22 pm What will happen if i use a 12v rechargeable battery instead of 6v battery shanika says: May 16. TAHIR says: February 6. 2009 at 10:17 am i got 12V 7A battery so can any one pls modify this circuit for it and i need more bulbs too pls help me abhay says: April 1. so you have 2 in every chanel. T2 (BD140) can switch up to -1. 2009 at 9:31 am Can’t i use any other pnp transistors(same ratings) in place of BD140. and the resistors are all about 0. 2009 at 12:07 am If you use a 12V battery instead of the 6V .Double amount of current will flow through the LEDs during battery mode (can cause damage to LEDs).5A so this won’t be the problem (24 x 0.5K each. Im new to electronics a this kind of hobby things. then this fault is most likely caused from the resistor R connected like this.02 = 0. 2009 at 12:00 pm ok its quite fine if the ratings are same peter nyondo says: March 12. try changing the values to 0.5/12/12 Automatic LED Emergency Light Circuit mhanelle says: July 31. General rule of thumb for LED’s is to limit current to 10 of the LED. 2008 at 8:35 pm What will happen if i use a 12v rechargeable battery instead of 6v battery? should i have to change any components? if so then can u give the exact circuit diagram. in other words there are now 24 seperate channels. 2009 at 7:40 am This is great information for anyone whoever wanted to know what the inside of a light looked like. 2009 at 9:17 am good site for hobbyists S Mukherjee says: December 28. Circuit will not work properly. For R3 – R14.circuitstoday. 2009 at 1:49 pm TAHIR Assuming that the LED’s you are using are standard white LED’s with forward volt drop of 2V and current consumption of 20mA. anaz says: June 13. Battery will not get fully charged.use a 1K resistor and therefore for a 6V supply use a 0. please let me know abhay says: January 13. www.com/automatic-led-emergency-light 24/31 . How have you connected the extra 12 LED’s? If they are just placed in series with the existing LED’s.2k vr1[preset] or short by 1k2resistance admin says: March 28. But what be the possible wattage of this circuit. I will try.How it works? Introduction to MPLAB IDE 4 Great Books to Learn Basic Electronics Frequency counter circuit Standard Library & String Formatting for AVR Categories 101-Announcements 555 Timer IC 8051 projects Amplifier Circuits Audio Circuits Automotive Circuits Basic Electricity Battery Circuits Cable TV Circuits Camera Technology Clipping and Clamping Circuits Clocking & Timer Circuits Conversion Circuits www. How much current required or what energy they consume.circuitstoday. I mean when LEDs are on. 2008 at 1:06 am Dear. Regards. Riaz Get Daily Updates via Email Enter your email Subscribe Latest Articles 8 channel light chaser using 8051 Blinking LED using 8051 4 Books to Learn 8051 Microcontroller-Indian editions Push pull amplifier Working with MPLAB IDE What is Real Time Operating System (RTOS). A good project.5/12/12 Automatic LED Emergency Light Circuit riaz says: November 6.com/automatic-led-emergency-light 25/31 . circuitstoday.5/12/12 Automatic LED Emergency Light Circuit Counter Circuits Counters Digital Electronics Education & Training Electronic Components Electronic Keys & Locks Electronics Books Electronics Jobs Embedded Systems Equipment Reviews Events Fan Circuits Filter Circuits Fire Alarm Fun & Game Circuits Gadget Reviews Ham Radio Circuits High Voltage Circuits Home Circuits Industrial Circuits Instruments Integrated Circuits Inverters Lab Manuals LED related Light Related Lighting Circuits Microcontrollers Mobile Phone Related Motor Related Nanotechnology Oscillators Peripheral Interface Controller (PIC) Power Controller Circuits Power Electronics Power Supplies Project Ideas Projects Proximity Detectors Radio Circuits Radio Transmitters Relays Remote Circuits Reviews Robotics Security & Saftey Sensor Circuits Signal Conditioners Signal Generators Speed Controller Circuits State space analysis Switching Circuits Tech News Telephone Related Television Related Temperature Related Test & Measurement Circuits Testing Components Three phase circuits Timer Circuits Tone generator circuits Tools and Softwares Transmitters Tutorials UPS USB Circuits Videos VLSI Voltage Regulators Like Us on Facebook www.com/automatic-led-emergency-light 26/31 . com Designed by Web Design Cochin www. 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