This simple, enhanced, 5V zero drop PWM solar battery charger circuit can be used in conjunction with any solar panel for charging cellphones or cell phone batteries in multiple numbers quickly, basically the circuit is capable of charging any battery whether Li-ion or Lead acid which may be within the 5V range.
Using TL494 for the Buck Converter
The design is based on a SMPS buck converter topology using the IC TL 494 (I have become a big fan of this IC). Thanks to "Texas Instruments" for providing this wonderful IC to us.
You may want to learn more about this chip from this post which explains the complete datasheet of IC TL494
Circuit Diagram
We know that a 5V solar charger circuit can be easily built using linear ICs such as LM 317 or LM 338, you can find more info on this by reading the following articles:
Simple current controlled charger circuit
However the biggest drawback with these linear battery chargers is the emission of heat through their body or through case dissipation, which results in wastage of precious power.
Due to this issue these IC are unable to produce a zero drop voltage output for the load and always require at least 3V higher inputs than the specified outputs.
The circuit of the 5V charger explained here is completely free from all these hassles, I have explained how an efficient working is achieved from the proposed circuit.
Referring to the above 5V PWM solar battery charger circuit, the IC TL494 forms the heart of the entire application.
The IC is a specialized PWM processor IC, which is used here for controlling a buck converter stage, responsible for converting the high input voltage into a preferred lower level output.
The input to the circuit can be anywhere between 10 and 40V, which becomes the ideal range for the solar panels.
The key features of the IC includes:
Generating Precise PWM output
In order to generate accurate PWMs, the IC includes a precise 5V reference made by using bandgap concept which makes it thermally immune.
This 5V reference which is achieved at pin#14 of the IC becomes the base voltage for all the crucial triggers involved within the IC and responsible for the PWM processing.
The IC consists of a pair of outputs which can be either configured to oscillate alternately in a totem pole configuration, or both at a time like a single ended oscillating output.
The first option becomes suitable for push-pull type of applications such as in inverters etc.
However for the present application a single ended oscillating output becomes more favorable and this is achieved by grounding pin#13 of the IC, alternatively for achieving a push pull output pin#13 could be hooked up with pin#14, we have discussed this in our previous article already.
The outputs of the IC has a very useful and an interesting set up internally. The outputs are terminated via two transistors inside the IC.
These transistors are arranged with an open emitter/collector across the pin9/10 and pins 8/11 respectively.
For applications which require a positive output, the emitters can be used as the outputs, which are available from pins9/10.
For such applications normally an NPN BJT or an N-mosfet would be configured externally for accepting the positive frequency across the pin9/10 of the IC.
In the present design since a PNP is used with the IC outputs, a negative sinking voltage becomes the right choice, and therefore instead of pin9/10, we have linked pin8/11 with the output stage consisting of the PNP/NPN hybrid stage.
These outputs provide sufficient sinking current for powering the output stage and for driving the high current buck converter configuration.
PWM Control
The PWM implementation, which becomes the crucial aspect for the circuit is achieved by feeding a sample feedback signal to the internal error amplifier of the IC through its non-inverting input pin#1.
This PWM input can be seen hooked up with the output from the buck converter via the potential divider R8/R9, and this feedback loop inputs the required data to the IC so that the IC is able to generate controlled PWMs across the outputs in order to keep the output voltage consistently at 5V.
Other output voltage can be fixed by simply altering the values of R8/R9 as per ones own application needs.
Current Control
The IC has two error amplifiers set internally for controlling the PWM in response to external feedback signals.
One of the error amp is used for controlling the 5V outputs as discussed above, the second error amp is employed for controlling the output current.
R13 forms the current sensing resistor, the potential developed across it is fed to one of inputs pin#16 of the second error amp which is compared by the reference at pin#15 set on the other input of the opamp.
In the proposed design it is set at 10amp through R1/R2, meaning in case the output current tends to increase above 10amps, the pin16 can be expected to go higher than the reference pin15 initiating the required PWM contraction until the current is restricted back to the specified levels.
Buck Power Converter
The power stage shown in the design is a standard power buck converter stage, using a hybrid Darlington pair transistors NTE153/NTE331.
This hybrid Darlington stage responds to the PWM controlled frequency from pin8/11 of the IC and operate the buck converter stage consisting of a high current inductor and a high speed switching diode NTE6013.
The above stage produces a precise 5v output ensuring minimum dissipation and a prefect zero drop output.
The coil or the inductor can be wound over any ferrite core using a three parallel strands of super enameled copper wire each with a diameter of 1mm, the inductance value can be anywhere near 140uH for the proposed design.
Thus this 5V solar battery charger circuit can be considered as an ideal and extremely efficient solar charger circuit for all types of solar battery charging applications.
For Higher Voltages up to 60V Solar Panel
For solar panels with higher voltages, such as 60 V solar panels, the design can upgraded by adding zener diode regulator at pin12 of the TL494, as shown below:
Questions & Answers
Hello sir, I want a 3 stage charge controller with current adjust ( 0-5 A ) for 12V CCTV UPS to increase battery life, power voltage is about 13.8V and battery is 12V sealed acid, Can you help me to design this charge controller with transistor?
Hello Ruhollah,
I will design it soon and let you know…
Thank you, I will wait for your favor
Here’s the circuit diagram which i have designed, I will write the description also and let you know once it is finished:
Hello, Thank you for circuit design. how much the P3 and P4 Variable resistance? how much the most current that this circuit can support ( 5A or up )? please change circuit without current limit too.
I have added the full description under the following article, please check it. But i think the LM338 current limit cannot work using a single LM338 IC, instead you may have use two separate LM338 current limiter stages for the current limit #1 and #2:
https://www.homemade-circuits.com/make-this-3-step-automatic-battery/
Maxx current is 5 amp if LM338 are used.
Without current limiting won’t make sense in this design…
Hello, Thank you for Description about circuit, How much resistance that connect to input +14.5V And Tip3055 IC?
Hi, it can be 50 ohm 2 watt…
Hi, thank you very much for design the circuit, description that and reply all questions. I don’t forget your favor. Be in the protection of God
You are welcome!
Hello sir, it’s me again Daniel. So, it finally worked, but it charges the phone at a slow rate and it’s a 15w 12v solar panel. Is there anything I can do to increase the charging speed?
Glad it worked, Daniel,
You can try connecting two panels in parallel and check the response, or you can increase the power of the solar panel rating
Hello Mr Swagatam! I’m in a place where there is no electricity, so I took with me a 12v solar panel which I will use to charge my phone or a lead acid battery for storing power when I’m not around. I used a USB QC 3.0 DC-DC buck converter charging step down module which can take 6 to 32 volt maximum as the input and give out 5v as the output, so I then plugged in USB type C to charge my phone it indicated charging but the phones percentage wasn’t increasing. So what do I do?
Hello Daniel,
That means your mobile phone is not accepting the charge from the source.
Please confirm the output with a meter to ensure it is 5V DC, or you can add a 7805 IC at the output and check the response.
Hi Sir Swagatam! It’s me again, Charm! I already have this circuit produced in a PCB. For the transistors, I used TIP32C and TIP31A which are TO-220 package. The NPN transistor (TIP31A) heats a lot. And I will be converting 24V input to 5V output. I would like to ask you about heat sink recommendations and specifications that I could use.
Thank you Charm,
The transistor must not heat a lot, otherwise it would defeat the main purpose of a buck converter. Can you tell me the current specifications of your circuit…it shouldn’t be more than 1 amp. And did you use an inductor with the correct inductance value?
Hi Mr. Swagatam! the current of the circuit is 1A. I used the same inductance value of the inductance. When I put my battery as the load/ output. the transistor Q2 heats a lot that I couldn’t touch it.
Hi Charm, what is the battery Ah rating, is it drawing more than 1 amp? Also, check the input side voltage, if it drops significantly then your circuit might not be working correctly.
I have 2 batteries arranged in parallel. Each battery has specifications of 3.7V, 2600 mAh.
The input side voltage remains 24V when I turn on my circuit. The output voltage gives me a steady 5V.
OK, that means the current draw is much above 1 amp. Those two batteries can draw more than 3 amps if not restricted.
Try with a single battery and check the heat, if the heat is manageable that would clarify the circuit is OK.
In that case you can replace the TIP31 with a TIP35, and then use two batteries.
hi Sir! I tried with a single battery which has specification of 3.7V 2600 mAh. the TIP31 is still getting hot. Any recommendations?
OK, in that case, please try replacing only the TIP31 with TIP35, and check the response.
Sir, What should be the voltage and ampere of TIP35? I have seen 100V 25A, 80V 25A, 60V 25A
Charm, Since your max circuit voltage is 24V, you can use the 60V version.
Hi Sir! When my battery is fully charged, will this circuit cut the charging process? If no, can you please suggest a way to cut off the charging when the battery is fully charged. Thank you so much appreciate your help
Hi Charm, auto cut off is not included in the above design. However, an auto cut off may not be needed if you keep the full charge supply to the battery a shade lower, for example at 4.1V (4.2V being the full charge level for a 3.7V Li-Ion battery).
Anyway, with 0.125 amp supply input your battery may take ages to get fully charged.
Hi Sir! To achieve the 4.1V as my input voltage, do i need to add an external step-down converter to reduce the 5V to 4.1V?
For the solar panel, i will change my solar panel input that has more power to generate atleast 600mA. Thanks a lot!
Hi Charm, you can add the following regulator at the output of your existing circuit. For the zener diode you can use 5.1V zener. Make sure to put a 1k across the output of this regulator while adjusting and measuring the 4.1v. Adjust the 1k preset for adjusting and getting the 4.1v output.
Hi Sir, I have an available buck converter module here, it uses lm2596. Can I use it to generate 4.1V? Thank you
Yes, you can use it to generate 4.1v, I had earlier suggested you the very same converter which is one of the easiest and most efficient.
Hi Sir! Please clarify the part where I need to put a 1k across the output of this regulator. Do you mean that after the Vout + and – I will put a 1K ohm resistor and after that will be my new Vout?
You are right Charm, It should be connected BETWEEN the Vout and the (-) of the previously linked circuit. The (-) of this circuit must be also connected with your PWM circuit’s 0V line.
Hi Sir! Do you mean, I will add a 1k ohm resistor after the Vout (+) and (-) of the PWM circuit. And after the 1K ohm resistor I will connect the Vin (+) and (-) of the voltage regulator using emitter follower transistor. And then connect my battery.
Hi Charm, you must connect the 1k across the emitter of the regulator transistor and ground. The output of the pwm circuit will connect with the input of this regulator circuit.
Hi Sir! 18650 li-ion batteries work with 1A current output. If I want to charge my 18650 batteries using this circuit, how can I generate 1A? I read the article that said its output current is 1A.
The output current will depend on the input current, and the inductor wire thickness. Please let me know how much input current are you suppling to the circuit?
Since I will be using a 1.5W 12V mini Solar Panel, my calculated input will be 0.125A. I am not sure if this current can trigger charging my 18650 batteries.
A 12V 0.125 amp input will not produce 5V 1 amp current, you will need at least 12V 600mA input to get 1 amp out.
hi Sir! I was able to generate 5V output with 24V input. My next question is, can I directly charge 2x 18650 li-ion batteries arranged in parallel with 3.7V using this circuit? If yes, what is the output current of this circuit to be able to charge the 18650 li-ion battery?
Hi Charm, Glad you could get the circuit working, and I hope you are now getting the intended frequency at pin#11 and pin#8.
You can charge Li-ion batteries using this circuit. The output current will depend on the input current.
Hi Sir. I will be testing the frequency at pin#11 and pin#8 at school tomorrow. I will let you know.
Sure, no problem Charm.
Hi Sir! I am thinking of the problem with my transistors and diode connected to my pin#8 and pin#11. I changed my transistors from NTE331/NTE153 to TIP31C/TIP32C. I changed the Diode NTE6030 to Schottky 45V 6A. And my capacitor is an electrolytic 2200 uF 35V. Can you advice if there is a problem when i connected this to my IC. I already changed my IC 2x to be sure my IC is not damaged.
Hi Charm,
Do one thing, remove the transistor connection from pin#8 and 11 and check the frequency without anything connected to these pins.
If still there’s no frequency then you will have to investigate the IC connections and configuration deeply.
Hi Sir! Do i need to connect pin#8 and pin#11 to VCC to test the frequency?
You don’t have to connect those pins to positive, just keep them connected with each other, and test the frequency across their junction and the ground, with a frequency meter.
Hi Sir! I tested this circuit with a 12V input with a power supply, however, instead of getting a 5V output, I am getting a 12V output. I am confused whether I will get 5V output despite having an input of 12V. Please help
Hi Charm,
Is your IC correctly oscillating and generating the required PWM frequency at the base of the transistors? Please check whether the IC is generating frequency at pin#8 and pin#11 or not. Try altering the RT, CT values and check whether the frequency is changing or not.
Once you confirm the above, next try reducing the value of R9 and check if that reduces the output voltage or not.
Hi Sir Swagatam! I changed my transistors from the NTE153/NTE331 to TIP31C/TIP32C because I could not find the NTE153/NTE331. At the base of the transistors TIP31C/TIP32C I am getting 12V output when I supply the circuit with 12V. Also at pin#8 I am getting 0.44V and at pin#11 I am getting 12V.
Should I expect 5V even if I have 12V input?
Hi Charm, With 12V at the input you should be able to get 5V at the output if R8 and R9 are appropriately set.
If you are getting 12V at pin#8 and pin#11 that means your IC is not oscillating and something’s wrong with the IC or the circuit connections.
You must check the frequency with a frequency meter or preferably using an oscilloscope.
Hi Sir! My R8 and R9 have 5.1K ohms each. Will there be any effect in the circuit with changing the transistor from NTE153/NTE331 to TIP31C/TIP32C?
i will re-wire my circuit with my IC to see my connections.
No, that will not have any effect on the new transistors.
Pin#8 and pin#11 are joined together with the base of Q1, so how are you getting different voltages at those points?
Hi Sir, I rewired my circuit in the IC. I used 24V input, I am getting 24V in pin#8 and 24V in pin#11. I am getting 5V on pin#14. But, my output is still 24V constant. Should it work like this? Do I need to add a separate voltage regulator to get 5V?
Hi Charm,
If you are getting 24V at the IC output that means your IC is not oscillating and is not working as required.
You must check the frequency across these outputs using a frequency meter or an oscilloscope.
No external regulator is required, since this buck converter itself is supposed to regulate the output voltage to the desired levels.
Dear Sir Swagatam,
For the CT, I could not find an electrolytic capacitor that has a value of 0.001 uF. According to the data sheet, this is the Capacitor used to set oscillator frequency. Kindly let me know if I can use a ceramic capacitor instead of electrolytic in this project.
Thank you!
Hi Charm, CT and C2 are actually non-polar capacitors, so you can use any ceramic or PPC capacitor for these capacitors.
Hi Sir! Thank you for sharing a much better circuit, but I already ordered components and did my breadboarding. The only component that is missing is the 2.5 uF. If I change the C2 to 2.2 uF, do I also need to change the resistance of my R7?
Hi Charm, R7 is not related to C2 so it can be as given in the diagram. R6/R7 determines the dead time.
C2 decides the soft start level of the output or for how long the dead time can be held to maximum until it returns to normal.
So C2 is also not crucial and a 2.2µF can be used without altering R7.
Here’s what the datasheet says:
Initially, capacitor C2 forces the dead-time control input to follow the 5-V regulator, which disables the outputs
(100% dead time). As the capacitor charges through R6, the output pulse width slowly increases until the control
loop takes command. With a resistor ratio of 1:10 for R6 and R7, the voltage at pin 4 after start-up is 0.1 × 5 V, or
0.5 V.
The soft-start time generally is in the range of 25 to 100 clock cycles. If 50 clock cycles at a 20-kHz switching
rate is selected, the soft-start time is:
t = 1 / f = 1 / 20kHz = 50µs per clock cycle
The value of the capacitor then is determined by:
C2 = (soft – start-time) / R6 = (50µs x 50 cycles) / 1k = 2.5µF
Hi Sir Swagatam!
I cannot find an Electrolytic Capacitor with 2.5 uF (C2 in the schematic diagram). Can you suggest any other alternative capacitor value? Also, if I change my C2, what could be the value to replace my R7.
I am breadboarding my project and really need your help on this matter. Thanks a lot.
Hi Charm,
I think you can use a 2.2uF instead, that won’t affect the working by much.
By the way there’s another much better circuit which you can try instead, here’s the link of that article.
https://www.homemade-circuits.com/0-to-50-v-adjustable-switching-power-supply-circuit-using-ic-lm2576/
Let me know your thoughts on this.
Hello Swagatam
Can tl494 be replaced by SG3525 bcs I don’t have the tl494 ic
Hi Klinton, that may not be possible, both ICs have different pinout functions.
Hi Sir Swagatam! I would like to ask if I can add a way to charge my batteries by plugging them in AC power, just like power banks so when there is no sunlight, I can still use my solar charger. Can this circuit handle AC?
Hi Charm,
If you want to use AC outlet to charge your cell phone then you will have to associate an SMPS mobile charger with the solar module. The SMPS charger can be any normal mobile phone charger.
Hi Sir! It’s me again Charm! I would like to ask what is the specification of you diode as I cannot find NTE6013 in the market.
Also, you have mentioned that I can connect both my back-up batteries and USB in the output marked +5 and 0V. Does that mean that when the PWM charge the back-up batteries, at the same time I can get power from the batteries through the USB; or the USB will directly get the power from the Solar Panel since both outputs – back-up battery and USB – are connected to the output?
Your kind response is much appreciated for my project.
Hi Charm,
You can use any 6 amp schottky diode instead of the indicated one.
The solar panel will charge both, your 12V batt as well as the USB batt, as long as sufficient sunlight is available.
I think you should consider trying the following circuit instead which is much more reliable and easier to build:
https://www.homemade-circuits.com/0-to-50-v-adjustable-switching-power-supply-circuit-using-ic-lm2576/
Hi Mr. Swagatam! Noted on the diode. I actually need to do a project that is a PWM solar charge controller that can also function as a power bank. So, I’m thinking of adding another circuit after the solar charge controller charge the battery so the USB can harness power from the battery. However, I would like to ask if the battery is charging through the solar panel, can I simultaneously draw power from the battery to charge my phone?
Hi Charm,
If your solar panel and the PWM controller components are adequately rated then it should be able to simultaneously handle both the batteries.
You can definitely another small buck converter circuit to harness the required 5V from the 12V source.
Hi Swagatam! Thank you for sharing this amazing circuit. I am working on a PWM Solar Charge Controller. I would like to know if I can use this PWM Circuit for a Charge Controller with a built-in Solar Panel and Batteries, like a solar power bank principle?
Thank you!
Thank you Charm,
Yes, you can use the above PWM charge controller for your application, it should work.
Thank you for your response Swagatam. Can you please tell me where should be the connection of my batteries? As I understood, the 23V input is from the Solar Panel. I wonder about the connection of the Batteries. Thank you
Charm, The buttery should be connected across the outputs marked as Out(+) and 0V. R13 value decides the max current output.
Almost forgot to mention my concern about tripping the overvoltage protection in the inverter which is why I mentioned pulling battery out of bank and using the diode to keep any of the high frequency PWM from sending too much voltage to that. It gets real close as it is with stuff like it is when the solar voltage goes over 14.5 which it does once in a while. I loose AC power until it drops back below. I’ve had to put extra draw on inverter a couple of time to pull the V down. But that is wasting power from my array that could be put in batteries if they would just take it and keep everything else running along nicely.
Me again, I see others have mentioned solar panels and other issue. What I need to do is use a pair of 12v nom. 25 watt panels as a source for a high voltage compared to normal voltage from a 12v charge system to work with a pulse width system, such as this TL494. I have a set of sulfated batteries I need to get brought back asap but I am having issues with my inverter system due to not being able to hold a voltage level adequate for the inverter during the night if I put anymore load on it from what I do getting through the darkness in my off grid RV. I have 400 watts of panels and a new MPPT which has made a significant improvement and another 200 watts of panels arriving any day now, planning on another 200 next month. I will be switching to a 24 volt bank beyond those 800 watts to stay with the same wiring installed now as the MPPT would be maxed out at just under 800. As far as I can figure, the max is rated at 750 but since there are inherent loses in the system, I should be able to get by, hopefully(?),or at least pull out 200 watts of panels until I can afford the 24v to 12v step down box. If I can get a working desulfator system functioning without having to purchase something like a NOCO Genius smart charger, I really want one of those anyway but it’s a money issue, which way to jump first? Buy, build? Winter is coming and my batteries are suffering but I must get them working again or else, more money I don’t have. So If I use 2 of the 25 watt panels to get the higher voltage needed to knock the sulphate crystals off, and build the PWM either by using a simple 555 circuit or a TL494 as is done here, I have some power supplies from computers I might be able to salvage parts from, along with the other stuff I have on hand. I would use either a linear regulator on the Vcc to keep 12v and work with the 42 volts OCV the panels would make during the off cycle which would be pulled down on account of the basically 12 or less in the battery until things hopefully snap out of it. Probably will be near the end of the month and then will have the funds to just get the NOCO. I might be able to get away with pulling out 1 battery, connect a blocking diode into the + terminal to keep the pulses from the desulfator going to any of the other batteries while running the inverter at night, just a little more draw. This is getting too deep to keep all lined out in my head. Anyhow, a little to chew on for now, maybe your engineering mind can do better than mine. Thanks in advance, and if you have some other idea, glad to look at it. I get into too much trouble with this stuff for my own good I know.
Thanks for the detailed explanation!Your knowledge seems to be better than mine, so i guess what you are doing is correct and should work.
Can this circuit be modified to deliver up to 12 volts and 30amps?. I’m currently working on a circuit like this but I don’t know how to modify this circuit to suit my spec of 12v 30amps, please I will appreciate you if you’ll help me out. Thanks
It can be modified to 12V 30 amps by upgrading the Q2 transistor to 50 amps, and the accompanying diode also to 50 amp. The inductor will also need to be upgraded to 30 amps
Nice work Mr. Swagatam
For Solar Charge Controller how do this circuit isolate/float/stop charging at full charge of battery?
Thank you Sammy.
This circuit will not auto cut off or provide float charge. For these features you may have to add external circuits.
This circuit will only convert a high DC voltage into a low DC voltage with maximum efficiency.
Hi my name is John and I am looking for a circuit for a mppt charge controller circuit to work with high voltage input say 36-48 volts and supply 12v output around 30-40 amps can you help
can i replace the npn transistor at the end with npn mosfet. for example like irfz44n or irf3205
The above circuit is designed to work with power BJTs so I don’t think the NPN can be replaced with a MOSFET. You can try some other equivalent power transistor if the indicated transistors are not available.
okay thank you my best teacher for the information. can you tell me the schematic that uses the npn mosfet to me. or tell me what should i change if i want to use mosfet as power
Thank you zen, I think if a N-channel mosfet is used then there won’t be any need for Q1, R11, R12. The mosfet gate can be directly connected to R10. R10 may need to be reduced below 50 ohms.
OK, I’ll try to change it. And I’ll let you know the results. thank you my best teacher
sure, no problem!
hey my best teacher i have tested this circuit. however I failed to replace the transistor with an NPN mosfet. but i managed to make this circuit with transistor. as you have explained. my question. why is there a ringing sound when the circuit is loaded with 5 amps and above? where is that sound coming from? I used a used choke inductor that was on ATX with yellow and red enamel. Then I combined the enamels in series to get more twists. all work fine when load is applied. and the temperature is also not too hot in all parts. yes it’s just a little heat in the bridge diode. because I installed 4 6A diodes. And I know it’s not high enough to support 15 amps. the output can also vary from 4-24 volts from the 30 volt input. what should i change if i want it to be variable from 4-28 volts? i’m using a 10k pot that i tied with 5k1. before you answer all my questions. i want to say thank you very much to you. with your guidance through your website I can get to know the world of electronics better.
Thank you Zen. I am glad you could build the above circuit successfully.
However I am not sure how to stop the ringing sound? Did you use a 140 uH inductor as suggested in the diagram?
Regarding making the circuit adjustable, as far as I know changing the value of R9 will allow the output to adjust the voltage accordingly.
You can try replacing R9 with a 10K pot and check how it responds.
ok thanks for the response. I really don’t know the exact size of the inductor. aha.. I’m starting to understand what the problem is. Up here I am satisfied with the results of this circuit. and that makes me very happy. now i will see another circuit in your website and i will try to build it
No problem Zen, Glad to know the above circuit is working for you! All the best to you!
Zen, I see this is a fairly long time since this was posted but I will give my thoughts on this. I am currently working on a circuit that is buck converter myself. 24v/12v, so in this circuit there is a final Q to drive an inductor also, the base of the Q is being triggered by a diode/capacitor voltage doubler. This section of the circuit is to hard trigger the Q to get it to turn on as high as possible so the loses are reduced. The thing is, BJT’s are current dependant triggering while MOSET’s are strickly voltage dependant so if the voltage applied to the Gate is increased, Not beyond the point of tolerances, they are fired very efficiently. Since MOSFET’s are generally so much more efficient at conducting over BJT’s ( much less power loss in heat) it is obvious why they are preferred in high power circuit. The big deal is choosing P or N channel. One usually work better for specific application than the other based on how the circuit is designed on paper first. You need to know differences in function based on High/LOW side arrangements.So, with that, consider including a voltage doubler section driven by the IC to trigger the FET, this is a good idea also if you wish or need to parallel FET’s to increase power capacity, obviously adding inductors also, each can be used modularly and be sure to include low R values between the output of the doubler and each G of FET so that all FET’s are sharing the load equally. Values around 0.1 to 1r should work,I think. I’m not an EE, this is just what I have read and seen in the past. Feel free to contact me if you have any replies or comments. We are all in this together and communication is key to innovation.
Thank you Bret,
I think the Q1 transistor being a PNP and its emitter hooked up with the input suply will have enough voltage to drive a MOSFET, if the Q2 is replaced with a MOSFET. However if Q2 is replaced with a MOSFET its gate will need to be safeguarded with a zener diode to prevent a high gate voltage, therefore R12 will need to be replaced with a 12V or 15 V zener diode.
I will try it later I will tell you the results
Hi John, I am sorry, I do not have the specific circuit you are looking for. MPPT is a difficult subject otherwise I could have tried to design it for you!