It is an SMPS design, and it will work for 12V 2 amp applications also. Can i use BC 547 transistor instead of BD 139? pls help me, Pavan, you can try and modify the following concept, https://homemade-circuits.com/smps-2-x-50v-350w-circuit-for-audio/. .the opto zener will also need to be changed appropriately. OK thanks for the updating the info, however I think inserting a paper between the outer arms of the E cores can be an easier option…. The transistor was TOP201Y and I checked for an equivalent that was TOP223Y but all were discontinued so I couldn't get it in any shops but data sheet says it's a 50w switching transistor so can u suggest me any switching transistor for this purpose. https://www.homemade-circuits.com/how-to-design-a-flyback-converter-comprehensive-tutorial/, Dear Swagatham, I request you to publish or send me a pcb layout for 60 vdc electric bike charger. Dear Swagatam, We are not finding the 5D11 NTC. 13. But can i replace ba159 with 1n4007(standard recovery)? SIR , I WANT MAKE 12V /10A POWER SUPPLY FOR INDUCTION HEATING CIRCUIT,PRESENTLY I AM USE TRANCEFORMER IT TOO BULKY,MY AIM IS MOBILE INDUCTION HEATER (WEIGHT LESS) SO ONLY OPTION REDUCE SIZE OF THE TRANCEFORMER ,COULD YOU HELP ME? The above action induces a voltage across the auxiliary winding of the transformer which results in a feedback voltage to the mosfet gate via the 2n2/100V capacitor forcing the mosfet to conduct even harder. Required fields are marked *. Hello What are those points near each coils in the circuit diagram? The zener associated with the optocoupler may be tweaked for getting different stabilized outputs for the desired applications. HiIs there any reason why this kind is switched topology can't be used as a (constant voltage) power supply rather than a charger? Components of Lead Acid Battery Charger Circuit. HI friend! Sir i want 5V 7Amp smps with 3843IC. there is some problem in my design which is already mailed to you.how to set hiccup mode in this? Here it has been fixed to about 14.4V which becomes the optimal level for charging a 12V lead acid battery. 3 wire strands wind up simultaneously instead of one single thicker wire, this helps in getting better skin depth, higher amp efficiency, and compact winding, TRANSFORMER SPECIFICATION FOR 12V 5Amp OUTPUT AND PLEASE HELP ME WITH SOME EXPLANATION ABOUT THE TRANSFORMER, the winding procedure is already explained in the article, CAN I USE THIS CIRCUIT AS 12V 5AMP SMPS POWER SUPPLY, yes you can, for more options you can check out this link, sir please send me the transformer coil inductance. Could you please explain me how the circuit is non-isolated while you used transformer? can it be tested using variac transformer?? Max current output around 5amps. Automatic 12v Battery Charger Circuit Diagram. At no load output is perfect. But you didn't mention that you can ship one 9V5A converter to my address, via courier? In this circuit green LED is used for indicating the charge of the battery. Another factor could be the use of higher frequencies, because higher frequencies will allow lower number of turns to be used, and vice versa. Thus the output of the capacitor unregulated Dc voltage. For curiosity I assembled this project but it is not working. The main supply voltage 230V, 50Hz is connected to the primary winding of the center tapped transformer to step down the voltage to 15-0-15V. Isolation is not required. can you please help me to design battery charger. I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. you can check it from the datasheet of the IC, or from Google images, it’s just a matter of a minute. When battery charges fully, the zener diode D6 which connected in reverse bias conducts. This battery charger is safety or not? it operates the same way? The 3amp should be at the secondary side not at the primary side, the primary side should not consume more than 0.3 to 0.5 amps…if it's exceeding this value then your transformer could be malfunctioning. 0.2mm gap in thier centeral legs. I have tried one and it produces 203ACV from 12dcv supply just by increasing the secondary turns, I only tested it to power two 100W filament bulbs (not too bright) and two 18Watts energy server light. Devendra, the transformer is quite critical here and will need to be correctly optimized, or else the devices will keep blowing of. of turns are different. Hello Mr Swagatam, I have built the power supply as you have detailed. Thanks. Battery charger circuit diagram with auto cut-off. I = V/R = 12.5/50 = 0.25 amps which looks fine to me. my output is 5.22v, and 1.5 amp of current. Hi Yamin, sorry I do not have a 100 amp smps circuit at this moment. Hello, The SMPS design in this article is truly great! I guess no other changes would be required, by modifying the ferrite transformer winding and the mosfet. Excellent circuit. If we use transformer, the size of 10 amp stepdown transformer is too big for our PCB and heavy too. Irf840 mosfet cannot be used in flyback like u sugested, it has vds=500v(max), a flyback mosfet must be rated @ 2 x bus voltage + marging. is it Okay if i use Ferrite Bobbin Core EE22PL3K /Ferrite Bobbin Core EE25R3K ? yes, the zener diode can be changed to a 30V zener for increasing the voltage, and also use more number of wires in parallel for winding the secondary of the transformer for enabling 10amp output. of winding can be used? I want to ask you some questions to define some issues. 3.Battery charger Using SCR. And yes this is one of the best blogs I found for electronic projects! Instead of the 4n35 what else can i use? I have one example ferrite core inverter design in my blog which comprehensively explains the method of converting the high frequency stepped up voltage into 50Hz output, you can learn it here: https://homemade-circuits.com/2014/07/5kva-ferrite-core-inverter-circuit.html. During this process, the voltage across the 0.22 ohm resistor situated at the mosfet source tends to cross the 0.6V level, which instantly triggers the transistor BC546, which shorts the gate of the mosfet to ground, rendering it completely switched OFF. do i need to make diode bridge or can i use single diode?please help sir…. auxiliary winding needs to be kept fixed as per the shown data regardless of any change on the other winding…it's only for triggering for the mosfet and for sustaining the osciilations, can i tweak transformer's secondary side turns and parallel wires to get 60volt 50amps as output from this circuit. yes you can, but not by increasing the diameter of the winding, rather the diameter of the wire cross section….this can be alternatively done by using many thin strands of wires in parallel instead of using a single thick wire. Thanks in advance, I would like to know about design of ferrite core transformer (ferrite core size), please help me sir. This circuit will give adjustable DC supply output and charges battery ranges from 6 volt to 12 Volt. in your schematic sir? the voltage ratio in this case is not close to the turn ratio of 30/5. It is giving us 12.5 V output but after few minutes all diodes in bridge , both ba159 and diodes 6a4 in output 18V zener and mosfet is blown(shorted). Pulse transformers are mainly used for providing galvanic isolation to the primary SMPS stage and for ensuring a safer operating environment to the vulnerable electronics from the high mains input…. Ajay, I would advise you to first try the shown 5 amp basic design, if you succeed then you can try upgrading it for higher amps…. Hi, a charger is also a kind of power supply so definitely smps circuits can be used as DC power suppies. Today we are going to build charger circuit for charging Ni-Cd Battery. at 0.2A x 220V input the 12.5V would be accompanied with 44/12 = 3.6 amps, and with 50 ohms the output consumption would be. The article discusses 3 unique charger circuits; you might develop the one that fits your condition. Pleas help! but only if the total requirement of all the units is within 4 amps, Hello SirHope so you are doing well.Sir i have made this circuit. 4n35 has only four legs, so the base is not applicable in the device….. thx sir, sir i want to ask again, what the function from NTC thermistor?and should i use 10k NTC? All that I am having is DMM only. Shigida, the coil is not too critical for home use. The DC output is a pulsating DC as there is no filter after the rectifier. However, if you happen to build it successfully feel free to shear your experience and data regarding the same, will appreciate it a lot. The current which would pass through SCR and battery as per Ohm’s law would be approx. A feedback stage across the secondary and the primary stages is implemented via a optocoupler which determines the required fixed, regulated output voltage. You can use the one which is shown in the following article: https://homemade-circuits.com/2013/02/using-ntc-resistor-as-surge-suppressor.html. Or any heating issue?if u run this smps constant up to long time min 12 hours? This prevents the deep charge of the battery. I want ask you plz about if the circuit work properly with you ? Did you consider using a linear voltage regulators, and what’ll be the required current output from the 12V? Hi Thanks! hello sir , i want to make a 8v,500ma & 5v ,300ma power supply in a 8051 ckt, in my opinion for this i should use double winding in secondary & reduce the thickness in secondary winding & change the zener.sir plz guide me, hello anutosh, you can at the most reduce the secondary wire gauge suitably, and change the zener to 8V or 5V that's all, no other changes would be required, hello sir, in my previous question i want to make both o/p in single supply ,for it in can i use double winding togather & apply zener on 5 v supply only, ashutosh, you don't have to put two winding, simply calculate it for 8V out and then add a 7805 IC with the output, so from the same winding you can achieve 8V and 5v together. A voltage divider network is used to supply a portion of battery’s voltage to inverting terminal (Pin 2) of LM358. By the way i think that most people complaining about mosfet overheating they used their EE cores as they came from factory. Ungapped. i got some and some failed. Is it possible? Dear sir! If you have any circuit related query, you may interact through comments, I'll be most happy to help! if yes than please give details. Thanks. It will work at low (30V) but self destructs at mains (240Vac). Thank you so much.Alan Santos. What modifications should be done to this circuit to be used with 400V DC. please check and help me with correct circuit and components. If there is a short circuit, can the power supply be damaged or burned? 1) On Charge LED emitted continuously. This would be a very large current which could potentially damage the SCR/battery. can i change output voltage from 11.5 to 14.5 v dc via preset.if yes pl suggest me preset connection with preset value. Wat detail or specification I have to give to shop owner.Thanks and regards. actually a high speed diode must be used in place of the 6A4 diodes, but you can go with the 6A4 diodes also, a single 6A4 will also work. you can try increasing the zener value to 24V, and also modify the transformer wires for handling 10 amps. The ferrite transformer is wound over a 15mm EE ferrite core compatible plastic bobbin. for 8amp current you must use an 8amp to 10amp fuse. 2-I cant find .4mm wire from store so can i use those taken from cfl transformer which is generally available ? Using this circuit the battery life I will also increases. thanks for ur kind responsei want to design a 70volt 15amps dc output smps (by refering to ur design)can i connect three sets of above mentioned smps rating in parallel to get a 70volt 45amps output. Yes, you are right, we can purchase a readymade one. Hi sir! Hello Mah, yes it will do, because higher voltage values will not do any harm. it's for dissipating excess power and for aiding the zener stage, it may be removed though, since the inclusion is not crucial. Hello Sir .I will give all data whaterver I had to your email I'd within couple of daysRegards, no problem style, take your own time and do it nicely , Hello Sir I have done only calcultion sir.still everything is in paper only.i dont know how to order raw material.Definitely I will give all detail … How to load complete detail can you tell me,actually its quite long,including gauge table and cross section table.or can I put directly into comment column?Regards. You must get it checked from an expert who knows all about switching circuits. Sir BA159 is not available in my city. Thanks for this circuit. each and every battery has there own initial current value (charging current) u have to charge according to that unless u battery may explode. Then when the circuit is powered ON, the peak AC voltage at the anode of the SCR1 would be 21V (15V rms). 7808 voltage regulator is used for constant supply to the operation of the circuit to cut at a required fixed voltage. IS IT POSSIBLE? 12v battery charger with auto cut off circuit diagram. I have noticed it only in video. Yes i did and work very good, no trouble at all. The output voltage of the battery charger should be less than 1.5 times of the battery and the current of the charger should be 10% of the battery current. Cl = 1000uF25V. Here, voltage is reduced and a current of less than 1% of the battery's capacity is applied. Only those mosfets which ca handle in excess of 400V will work here, the ones you have suggested won't work. I connected the 330v dc output to the smps wrongly suddenly my switching transistor blasted . I finally made the BD139 based circuit and as expected – IT DIDN’T WORK. with component name. The bright 100 watt simply indicates that your circuit is not oscillating and it’s short circuiting the input supply through the mosfet. No components are getting hot or damaged but no output voltage. Now the 10K adjust the voltage very well but without SCR the red LED only turns off when it is higher than 13 V. I always use components from old electronic devices. In this article we study a simple flyback based converter design which is implemented as an SMPS 12V, 5amp battery charger power supply, without using a iron core transformer. I have not studied about this formula yet, so I cannot say much about it, I will do some research and then I might comment. Thanks Xavier, the diode and the capacitor polarity must be done according to the "dot" for the secondary, that's correct, but suppose if it's done the wrong way, in that case the output will simply show no voltage according to my simulation…because the output from secondary are ordinary rectangular waves, with positive peaks at the "dot" side of the winding. Hello Stewart, This design is for 220V operation and is thoroughly and successfully tested by many of the blog readers. The one half primary is wound first, using a 0.4mm super enamelled copper wire (15 turns). Below charger automatically shut off the charging process when battery attains full charge. Would this be able to work if my input voltage to the circuit was a varying DC voltage? according to ur circuit u dont want to worry about the voltage. ""Life is too short, cherish the you have by doing what you love and enjoy the most, provided NOBODY GETS HURT"". ??? I have constructed this charger. hi guys! Hi, thanks….here "transformer-less" refers to the elimination of the big bulky iron core transformer, and the "compact feature"….and "not isolated from mains" refers to the circuit as a whole, which is dangerous to touch while experimenting in an unenclosed condition and switched ON. The working of this circuit is explained below. Parts List for the 12V automatic car battery charger circuit: All resistors are Of 1/4 watt unless otherwise specified. The circuit is nothing but a 12V DC power supply with an ammeter for monitoring the charging current. Pls, what do I do? thanks sirbut i want to place preset for selection of voltage range from 11.5 to 14.5vdc?kindly suggest me preset value with connection.May i connect 22 ohm preset in series with zener 15v? 2 thoughts on “ 6V / 9V / 12V Battery Charger with Constant-Current Charging ” Mohammad February 19, 2015. This is a schematic diagram of a full automatic 12v battery charger for charging the batteries of automobiles etc. Hello Raymond, you can wind the secondary with 24 number of turns with a center tap at the 12th winding, and change the output zener with a 60V zener. You can leave battery charging in this state forever and no harm occurs to the battery. I have found the following problems. biannz, you can connect the input directly without the EMI coil, it's there only for suppressing noise. LM317 acts as voltage regulator and current controlling device. Hai sir , I need 60v/3amps charger circuit for battery charging . I can send you the circuit. Dear Skl,Th-NTC is a 350V NTC thermister. Please give me exact sizes of EE transformer. The 15V Zener diode is used to set the LM317 to supply 16.2V at output in the absence of load. Hello Parag, the details are given at the bottom section of the article. becoz 5.22 v is safe to charge. Dear Swagatam, I need one small help. it works really well and thanks for your advices.. is there a replacement cap for 2.2n 100v? Syed, any equivalent fast ercovery diode will do. Sir, wouldn't the mosfet fail against the emf generated at switching off .. D.Sir, kindly tell me how to make an adapter that( shuld be 13.5 volts with 5 amp) from smps? Dear Manager site map I have at my disposal. AUTOMATIC BATTERY CHARGER Abstract In this study, charger is designed for 12V sealed lead-acid batteries. for testing purpose you can do it, but for the final use it must be replaced with a fast recovery diode…, And can i use 0.25mm wire for all winding? dear sir i have design an smps with output of 5Amp & 14.5v, giving the output with no problem. always connect a 100 watt bulb in series with the input AC supply, in case if something goes wrong…. Circuit is taking 0.2A at its input 230 V and we are applying load of 50ohm. If you scope the secondary AC output, you will see that it is asymmetric (eg more negative-going than positive). sir i want to make power supply for 1watt LED drive. Secondly i have seen some smps design using pulse transformer.. Can u explain me th role and functionality of pulse transformer in the smps..? I added a 4N35 to control the charge of my battery when there is no power from the wind and the sun. You can try the following concept, ignore the current control section if you don’t wish to use it. BUT12A instead os SCR. So these circuits would not be very useful. There's one alternative in the form of TNY tiny switch but the configuration for this IC is different to the TOP IC in terms of their connections with the opto coupler…so it won't be of any good either. Thanks, Dear Sanjeev, I do not have the exact data, you can try 50 turns of 26SWG magnet wire for each side, over a ferrite ring core. Finally continue from the secured end of the first primary winding and wind 15 more turns over the above auxiliary wind to finish of the ferrite transformer coils. it damages the mosfet. ok sir but if eliminate the EMI coil that mean it should connect straight to the A/C plug? the trafo wire might also need an upgrade, more parallel strands should be tried over the existing winding. A 12V battery shows 14.4V on DMM when fully charged, so set 14.4V on the … 3 Transistor 100 meter ranged FM transmitter circuit diagram; Simple one transistor FM transmitter; 12 v 5 a lead acid battery charger circuit with PCB; 50 watts audio amplifier circuit diagram; Working of Automatic Battery Cut Off Circuit. The NE555 IC detects the voltage variation in pin number 2 and 6 will turn off and turn on the relay. Yes, but sir, can 1N4148 diode handle up to 1KV of Voltage and 2A of Current? Our existing circuit needs 12V 10 amp DC. Armaan, the details are already given in the article, you have to do exactly as per the given specifications, thanks for your quick reply i was a little worried have a gud day sir, hello sir i have a question can i use a 4pin optocoupler when i do not have a 6pin optocoupler with me thanks, Hi Olupot, yes you can use it….no problem. The voltage i want is 35volts.What type of transistor is connected to the 1k ? in order to make the SMPS variable, you can try the instructions provided in the following article: any 4 pin opto can be used, that's not critical. 4) 12V 100 Ah Lead Acid Battery Charger Circuit 5) IC 555 Lead Acid Battery Charger Circuit My question is simple : I am planning to construct a charger for my batteries car witch are 12v – 60AH to 80AH capacity (several batteries). And what is the function of the POT in the “Battery Charger Circuit using SCR”? What information they are telling? pleaseeeeee I am not sure about this mosfet equivalent. I mean we're switching off ~ 5 Amps of the primary in a snupper of 10nf and 18kohm that will create almost 4kv at the drain !! No doubt it’s been utilized here too for yet another useful application. This process is also called as rectification. Only the components values and transformer no. The author told me I'd need 4 separate 12v supplies (3 for the high-side bridges, 1 for all low-side bridges would be fine). I couldn’t get the POT working – the voltage control never worked. I have done this circuit severally. I can't easily want transistor driver instead of ic but with no opto. Thank you very much sir. How […] Article by Swagatam Innovations. Terminate the ends on the secondary pins of the bobbin. Of turn,Gauge etc. ?thx, Fajar, you may have to increase the secondary turns from 5 to 12, and increase the associated zener diode value to 36V, for reducing current you may try using thinner wire for the secondary winding, although this may be an irrelevant parameter, you could use the same circuit for any purpose, just make sure that the load voltage spec is not lower than 34V. In the transformer i wound for my circuit, the middle leg of core has a 1mm gap when its side legs fit together, may i have problem with it? It is better to charge a battery with a current ten time smaller then the battery capacity. Hi, Is it enough or should be more or less? Hi Its going to be connect to 110 a.c, 1K is connected BC547…please click the diagram to enlarge. Your email address will not be published. Thanks, Hi Zakie, It can be difficult to troubleshoot the fault because I cannot check what may be the problem in your circuit…the ferrite transformer is the crucial thing in the design, if it is not wound correctly then the circuit will simply not respond or even burn into flames…so check the transformer once again and also the other connections. x 3 could mean 3 wires held together and wound together in a bifilar mode. I want 24 – 36 volt dc supply at 5amp. the trafo winding specs must match the indicated data, otherwise it won't work, SIR,WHAT DOES 6A4* 2 NOS. I am trying to design a circuit to charge (2) 12 volt 10aH sla batteries using the power from bicycle pedaling. The Gate of SCR1 is at higher potential than Cathode and hence SCR1 would conduct. Any help would be appreciated . inductance is not there with me, but the winding details is given in the article and should be enough for the construction. It's for suppressing the initial high current inrush by providing an increased momentary resistance. Infact there is no way to regulate and measure the output voltage properly at ‘no load’ condition. i need perfect design . Diode Type StandardVoltage – DC Reverse (Vr) (Max) 600VCurrent – Average Rectified (Io) 2AVoltage – Forward (Vf) (Max) @ If 1.1V @ 2ACurrent – Reverse Leakage @ Vr 5µA @ 600VSpeed Standard Recovery >500ns,>200mA (Io)Does it work here, It is standard recovery diode?????? Thank u sir for your immediate response..bcz of white background cant notice. I would suggest you to go ahead according to your suggested formula results, and in order to increase current you can use many number of parallel strands for the primary winding, let's see how it performs, I have a smps from a vcr which gives 5v and 12v but I don't know the ampere . Thank you very much for such circuit giving me the chance to build my charge control. Is there any way to change the minimum and maximum voltage of Battry??? Just have to understand Battery charging requirements only. Lm317 voltage regulator output is applied to the battery through the diode D5 and resistor R5. Sir, I have an SMPS, who's NTC is blown and the problem is not mentioned any value in it ,how to find the value. Greetings from Mexico. Thanks Swagatam for creating the site and maintaining this blog. You should use an input voltage of 15-volts or 1.5 times of a battery voltage. Hi , I am just curious to know if this could be used to charge 2 12 volt slap batteries in series with the input voltage coming from the pedaling of a bicycle connected to a motor with the polarities reversed in order to create voltage. But, our charger works on 12V, hence with the help of a Voltage divider circuit the value of (0-14) Volt is mapped down to (0-5)V using resistor R1 (1k) and R2 (500R), like have previously done in 0-24v 3A Regulated Power Supply Circuit, to display the Voltage on LCD using Arduino Nano. So I think your circuit may be having discrepancies that’s why it’s not working. We are looking for sm lightweight transformerless power supply solution. Its giving exactly 12 Volt output without load. Your fast reply is highly appreciated.