Replacing the potmeters on the 300 W, 20 A DC-DC converter
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- เผยแพร่เมื่อ 6 ก.พ. 2025
- I had to do some repairs on my DIY power supply and I had to replace the buck converter in it. I thought it might be useful for some people to see how the voltage and current adjusting potmeters (CV and CC, respectively) are wired up and how they can be replaced. It is not a complicated task, and I recommend doing it if you want to change the output often. It is not too nice to adjust the live circuit by a tiny screw very close to the connections.
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This is exactly the info I wanted! Hard to find. I just want to swap out my converters trimpot with ones I can mount on a panel! Thank you!
Glad to hear! Make sure you use quality potentiometers.
i enjoy watching these videos, i keep destroying these buck converters and boost converters, i just tested my last failed buck converter just like this and one of the pots reads as if its not there. now at least i have something to start with. i think i have extra parts laying around.
Hi! It seems like it is easy to fry these circuits. Quite a few people told me that they fried theirs. Hope that my videos will be useful for you.
finally someone shows what i wanted to know. thanks for the awesome video!
Glad to hear it! Cheers!
Good job.
Did you find a way to make a short circuit protection for this buck converter?
Thanks! No, because I wasn't even looking for it.
Thank you for this video, you covered everything that I wanted to know about this converter. LIKED and Subscribed already.
I am happy to hear that you found what you were looking for!
A standard JST socket fits perfectly. Easy to fit and far more adaptable. Someones not done their homework.
What's wrong with soldering? A solid mechanical and galvanic contact. It is not about homework...
I absolutely hate those trimpots because they are so fiddly. They are loose when delivered! ( wobbly on the board). I have bought a usb power supply with a brass large knob that works great with that little step up dc to dc converter. On Aliexpress you can buy the little USP dc to dc boost converter for 5 dollars AUD. Is it cheaper to buy a few of these and replace on the regular dc to dc buck/boost converter? Any reply appreciated cheers from Australia 👍. Subbed and liked 👍
Hi! Thanks for the support! Yes, those trimpots are not comfortable to use. It can be even dangerous because they are located close to the terminals. If your screwdriver slips while you are trying to adjust them, you can accidentally touch the wrong things. Not really harmful, but might fry the board. If I am looking at the right product, then the difference between this thing and the little USP DC-DC converter you are referring to is that this one can deliver up to 20 A (with active cooling!) while the other one is only up to 4 A. I would say, it is up to you. If you don't need that much current, then the other product might be better due to its compact nature and built-in features. Cheers from Sweden!
@@CuriousScientist thanks for the quick reply. Cheers 👍
@CuriousScientist I was hoping that I could find the different trimpots? Is there a specific name or code?
WXD3590. But pay attention to the resistance! It must be the same as the potentiometer on the board.
@@CuriousScientist thanks for that!😀
I just recently received one of these units with the clear LED indicator. It doesn't work at all. When I inspect it, there is no pad between the transistors and the heatsink. It's directly fastened without sleeve on the screw. Do you think this is the reason it doesn't work? There is a diode near the input voltage so it might be wired differently.
Hi! The SZBK07 module that I hold in my hand right now has a pad and a sleeve for mounting the MOSFET, however, I don't see its purpose. The whole heatsink is supported by the MOSFET and it is not connected anywhere in the circuit. So, it is floating, therefore it would not matter if it was with or without those accessories. Furthermore, I assume that the pad itself is only there for heat transfer and not for any electrical insulation.
How do you power the DC-DC converter? What power supply do you use? What is the input voltage and maximum possible current? What is your load?
@@CuriousScientist I think the purpose of insulation is to isolate the heatsinks, so there isn't a voltage on the exterior of the package. I agree that these are not otherwise electrically connected. I removed the heatsinks and mosfets with them, and verified no electrical connections or pierce through the PCB. I also verified each mosfet using a component tester. I'm supplying the input with variable voltage from a hp E3633A 20V/20A and output has a 50 ohm 10W resistor. Around 6-9V I get a few mA of draw and essentially 0V on the output. When I crank it up to 10-12 I suddenly start seeing voltage & current on the output, about 2V less than the input. I've turned both CC and CV lock-lock until I could hear faint clicking indicating the end of travel, they have no effect whatsoever. Under a microscope everything looks perfect. I'm starting to assume it's a faulty control chip. I have another module purchased months ago that works fine, slightly different PCB and uses the isolation sleeve and pad on each mosfet.
It could be a faulty chip, yes. Have you tried turning the potentiometers in both directions? I guess you are aware of this, but even if your CV is maxed out, if the CC is still at zero, you won't see any voltage (Ohm's law, basically). And of course, this is true the other way around. If you have a 50 Ohm resistor as a load, then at 10 V you should see 200 mA on the output.
You also mentioned that you have a variable voltage PSU. What was the actual voltage and current setting? 20 V / 20 A is I assume to be the specification and not the actual setting.
@@CuriousScientist I am varying the voltage and it is staying in CV mode. It didn't reach the current limit and thus never went into CC mode. There are two modes, 8V produces up to 20A and the 20V mode something less. Use this unit daily. The module is probably DOA and will use it for parts. I already got a refund. I was interested in figuring it out, but without a schematic for this particular circuit I cannot troubleshoot the chip. I'd rather spend another two bucks and do something else with my time! But I like to figure things out...
Can you tell which controller ic is used
LM25116 if I am not wrong.
@@CuriousScientist Thanks for replying. That is correct. I checked now only.
3:33 I don't understand. The trimpot of the buck module is model 3296 and at this minute I can see that it is turning the trimpot "head" counterclockwise, but instead of decreasing the value in ohms indicated on the multimeter, why is it increasing? If it were not ohms but volts and it is turned counterclockwise, the value of the volts shown on the multimeter tends to decrease.
Well, this is how potentiometers work. In this demo, one probe is attached to the wiper and the other is to one of the other pins of the potentiometer. The potentiometer is a voltage divider made of 2 resistors. While one side of the potentiometer (one of the resistors in the voltage divider) increases its resistance, the other decreases it when you turn the screw on the potentiometer. So, when you fully turn the potentiometer to the max, you can measure the nominal resistance of the potmeter between the wiper and one of the inputs pins, while you will see zero resistance between the wiper and the other input pin. And the opposite will happen when you turn the potmeter to the minimum. The previously 0 Ohm pin pair will show the nominal resistance and the other pair will show zero.
@@CuriousScientist OK, I understand. But one thing is for sure, the potentiometers that come in any buck/boost module are very accurate, but replacing them with normal potentiometers as you show in the video, their accuracy is lost. Do you know any way to get accuracy with normal potentiometers?
Yup! You can use multiturn potentiometers like I did in this video:
th-cam.com/video/LODoeP6Ap1c/w-d-xo.html
@@CuriousScientist I have seen your video, but the multiturn potentiometers you used are very expensive and I am referring to the single potentiometers you used in this video. I'm building a lab power supply with an ATX power supply and I want to use two simple potentiometers to adjust the voltage, (one potentiometer for fine voltage adjustment and another potentiometer for coarse voltage adjustment), but I don't understand how to make the connections between the two potentiometers together with a buck module. Do you have any ideas?
Go to my website and check out the tools section. I have a link for the multiturn potmeters where they are not too expensive. At this moment when I am writing this commend (2021/Oct/20), they cost $1.86 per piece. You need only two of them, so I guess it is not a big deal. Adding coarse-fine potentiometers is a bit more complicated, or at least it is complicated enough that I cannot easily explain it in a comment without drawings. But I might make a video about this in the near future because this is a useful thing to have.
I replaced those trimpots with your brown ones in the video but the potentiometer is burning when tune them? I replaced 10K and 100k as well potentiometer. After that the module is not showing output. May be the potentiometer cannot the power ?
Many of these potentiometers are garbage. I noticed in other circuits that they just start to throw sparks and stop working. I suggest to source them from reliable sources or buy branded ones such as Bourns or ALPS potentiometers. You can also double-check the wattage of the potentiometers.
Hi, don't you think a multi-lap linear potentiometer would be better? I believe that accuracy derives from that but I could be wrong ... forgive my bad English!
Hi! Of course it would, but when I made this video my budget did not allow me to use them. :) I have more recent videos where I use those multiturn potentiometers.
@@CuriousScientist Ok, I asked this question because I'm going to insert one of these modules on atx for pc in the 12v output, I think it should work .... the potentiometers are 100k true?
100k, both CC and CV. Pay extra attention to the polarity of the potentiometers!
ok! An important question: in that module the output voltage is always less than the incoming voltage? For example if I have 12V entry, can I get a output current than 12V?
The current is measured in amperes and not in volts, so your question doesn't make any sense. However, this is not a boost converter therefore the output voltage will be always lower than the input voltage.
I would have thought it better to replace those pots with multi turn ones, as the Volts & Current setting will be more precise.
You are correct! But at that time when I made the video I did not have the resources to buy them. I have a more recent video on this topic where I use multiturn potentiometers. I also discuss about the mistakes that many people do when replacing the potentiometers which results in damaging of the circuit.
@@CuriousScientist OK no problem. I am just ordering some 10 turn pots for a board I have had for a while. Its a buck only and has volts and cc pots, it drives me crazy not being able to find the tiny slots.
Yes, it is very annoying and dangerous to poke around that tiny screw with a screwdriver.
When you replace the potentiometer, please double check the polarity of the potentiometer! Many people mess up the wiring when they replace the potentiometers. Some multiturn potentiometers have their pins in a 1-3-2 order instead of 1-2-3.
Hello
I changed the potentiometers from 3206 100k to 3590s-2-104l and I have a problem. The voltage regulation is correct, but the current regulation does not respond. Is it related to the power of the 2w potentiometer. How to solve this problem? sorry for my not perfect english :)
Hi! No worries, your English is pretty good. I had a few comments on potentiometers not working properly and most of the time it was a "user error". It was usually bad connections or soldering or wrong polarity of the cables. I suspect that you might have connected the potmeter in the wrong way. It does not really matter for the voltage because in that part of the circuit the potmeter is used as a rheostat, so the wiper is always tied to one of the other pins. However, in the current control part, the potentiometer is used as a voltage divider, so the polarity becomes relevant because all the 3 pins are independent. The default potmeter in these boards have the "normal" 1-2-3 polarity, where 2 (middle pin) is the wiper. However, the 3590 multiturn potmeter has the 2-1-3 pins (3 is closer to the knob) and the wiper is the pin 2. So, you have to wire it differently than the default potmeter. It is always important to read the datasheet of the products that you use.
Does the potentiometer value matter?
Absolutely! It must be the same value.
Hi , can i use this buck module for battery charging . Like fixing output voltage to 14.4v & adding mosfet at output and controlling it with arduino pwm to control current . Is this fine !. Please let me know.Thanks in advance.
Hi! Why would you bother with the extra mosfet? This module also have a current adjustment option (CC potentiometer). However, I am not the best person to ask when it comes to battery charging with this module. I have never tried it for this purpose, so I lack of knowledge and information.
@@CuriousScientist i have made a board which consists of lm2596 it has only voltage control.
Okay, but this is a different board and it also has a current control.
@@CuriousScientist yeah right , but wanted to know if thats possible.
I did same as this video but voltage regulator burned.then changed with 500k potantiometer.but this burned too.what poblem I dont know.
What potmeter did you use? Maybe wrong connection. Also, try to start the converter with the potentiometers set to the middle and there's no load on the output.
I have soldered a 100k ohms potmeter to exactly this 20 A DC-DC converters constant current spot. But when I rotate the potmeter the currenct goes only from 0% to 20% current. If I rotate it any further it jumps instantly to 100% current. Can you explain this behaviour?
Have you checked with another 100k potentiometer? Maybe it is just the potentiometer... I tested the whole circuit by messing around with both potentiometers and never had this issue. Also check what kind of load you are using...etc.
@@CuriousScientist Thank you very much for the fast answer. I checked again and I found a loose connection. After fixing that the potmeter somehow got faulty. I swaped it with a new one and now everything works as it should :)
I just think that the behaviour I experienced with the potmeter / dc-dc converter was really weird. (It somehow working for low loads. But after a 2A threshold it would just jump to 100% / 10A instantly)
I am glad that you solved it! The circuit is really sensitive for bad contacts or lack of feedback, so it can behave weird if something is not 100% OK with the CC and CV potentiometers. Also, be careful, because you can easily destroy the MOSFET in these boards. I saw several complaints about it, especially when people replaced the potmeters and messed up something (for example, poor soldering) during the process. The sudden jump might have been caused by the bad potentiometer too. Maybe the internal contacts of the potmeter were okay between the values you mentioned, and above the 20% current, it went to fully open or closed which then made the circuit go bananas.
@@CuriousScientist Thanks for the input. I hope i didnt damaged the Mosfet x). Because I tried some stupid things with this circut, befor I found the bad connections error.
I tried various different Potmeter with different values. (Which should not harm the circut). But I also tried reordering the connections from the circut to the potmeter. Because I wasnt sure which connection from the circut goes to which connection on the potmeter. That might have been a bad idea. But for now it seems still to work.
I have a more recent video where I tested this DC-DC converter with several different potmeters. They do not do any harm, but only cut the range of maximum output current/voltage. Flipping the connections are also safe as long as you did it symmetrically. If you just flip the two sides of the potmeter and leave the wiper as it is, you just flip the starting point of the potmeter, so instead of going from 0 Ohm to 100 kOhm, it will go from 100 kOhm to 0 Ohm. That should not do any harm either, as far as I know. Also, keep in mind that the CV potmeter acts as a rheoistat and the CC is wired as a voltage divider in the circuit. I suggest you to check this video if you are curious of these things in more details: th-cam.com/video/43INmzkNz8o/w-d-xo.html
Very informative. What type of pot works with LM25116?
I don't know which potentiometer is used with that specific regulator. Use the exact same value that you already have on the board. I also used the same value, I just switched to another form factor.
@@CuriousScientist it says 103 printed on pot. And i bought 100k ohm. Do you thinks its the same value?
103 is 10k. 104 is 100k.
@@CuriousScientistGreat. Appreciated it.👍🏼
When i install the pot with wiring should i remove the built in pot install to the board or i can leave it and install the new pot with wire? Do you have a diagram how to wire them? Or just follow how you wire the pcb and pot that you make on your post. I’ve seen on youtube that every pot has a diffent wiring diagram base on model. I’am a newbie with this kind of unit that’s why i have a lot of question to ask you. Thank you in advance. 👍🏽
Help!!! So i replace the 104 trimmer potentiometers with 3590s 100k potentiometer but after turning it on it worked for few seconds and the output became 0v even after changing the potentiometers to the 104 trimmers the output still stays at 0v
Did you pay attention to the polarity of the new potentiometer?
@@CuriousScientist yes
Maybe there was a short somewhere or something like that. I heard from a few people that their boards popped and they could not use it anymore. I also destroyed 2 boards, but then 10 others are still working just fine. It is hard to say anything without seeing the circuit.
one of the board died because of short circuited and looks like the other two damaged the ic because I used single core wires to connect potentiometer and they acted as a antenna and destroyed the ic
My module dead when replace trimmer to potentiometer. May i know why? Already 4 module i did it dead. Sorry for my english
Your English is good! Do you use same value, 100k potentiometers? Do you make sure that there are no short circuits? I tested it on four circuits too so far and all of the have worked fine. As you see in the video, it works just fine.
@@CuriousScientist yes sure no short circuit after soldering. Well i done extend that potentiometer. After 10-20 minite use later, i heard pop. Then voltage goes to zero. Value is correct. I,m use 104 10 turn potertiometer
Have you measured the input and output voltage and current during the use? How much load you put on it? Can it overheat?
@@CuriousScientist i'm using 36volt ac to dc module power suply. Actualty i dont put any load yet. While rotating the potetiometer to value i need, i heard pop and voltage goes to zero. And led on the module do not light up. Do you have any sosial media platform? I will sent picture for you
@@usahapetani9743 maybe you want to carefully read my website and TH-cam page... :)
good day sir. I have "8A Automatic Adjustable Step Up Down Boost Buck Converter" and i want to replace trimpot with potentiometer ? how can i find the rating of the trimpot and what compatible rating of potentiometer and multi-turn potentiometer should i use?
Hi! The details are written on the potentiometer. Read them, Google them and you can find their datasheet. Then search for potmeters with similar parameters, simple. If I am not wrong, this SZBK07 uses 3296W-1-104LF potentiometers. 100 kOhm and 500 mW.
I did this experiment.
But I found a problem with the potentiometer.
That is, the potentiometer experiences heat and there is a small spark.
The potentiometer I use is also the same, 100k ohms.
What is the cause of this problem, and how to solve it?
Are you sure that you haven't mistaken the polarity of the potentiometer? I have replaced several potentiometers and never had an issue like that. Check the pins of the potentiometer carefully, because even the same looking ones can have different order of pins. It could be that you've fed the input voltage to the wiper of the potentiometer.
Hi. There is no information in your video about minimum value of CC mode. I just bought two of this modules and I want to know is it normal to have minimum constant current about 1.3 ampers? I expected a value in milli amper range. can you test this if you still have module.
Hi! Yeah, I have dozens of this module, I built a lot of regulators and power supplies with them. If I don't forget it, I can take a look at it during the weekend. But I have the impression that this module is not really made for mA precision. I will look at it and check it.
@@CuriousScientist Thanks.
@@CuriousScientist 🙄
🤷♂️
(BTW, emoticons don't help. Instead of inserting one, you could have just asked if I did anything. )
@@CuriousScientist 😅Hi, it was just a reminder, I was actually waiting for your response during the weekend.
Nicely done. Buying this sort of modules I also noticed slightly differences between them and I don't think they are improving something, is more like some factories are copying wrongly what others built before :)
Thanks! Yes, it seems like that some manufacturers are cutting corners. It is not a healthy practice in my opinion. But I was really surprised and happy when I saw that the better board had a dedicated place on the PCB for that small capacitor. It makes it simpler to replace the potmeters. Until a point, I was also thinking about removing the switch and add a flip switch on the front panel of my DIY power supply, but I did not have the patience for that.
@@CuriousScientist if i have a 72V battery and i want to step down to 12V
Can i connect the Vinput of 2 converters in series? This will technically give 36V for each on the in put side and 12V 20Amp on the output side
Is this doable?
Btw i know that i have to put a diode in case i wanted to connect the outputs but I dont... i will only connect the Vinput in series and the output left independent
@@FirstLast-tx3yj don't do that, it will damaged the buck converters on high loads, just buy a buck converter rated for higher voltage. There are many you can find online
This is the way! Just use a higher voltage buck converter. There are many on the market.
Sorry, I didn't see the question. If someone writes a comment under someone else's comment, I don't always get notified.
Now your output is limited right?
What do you mean by that? The output is always limited by the values set by the combination of the CC and CV potentiometers.
When i replace pots as you did my pots smoked out i bought 3 of them one of them is not working now but the others making sizzling sound when i reduce voltage below 2 volts have u any idea what that is for?
It can be that you messed up the wiring. Always check what is the pin layout for the potentiometers. I've been using this power supply for a year without any issues. The PSU cannot go below 2 V, that's why you might have issues. This DC-DC converter has a minimum output voltage which is around 2 V.
@@CuriousScientist so can u guide me on how can i reguldte from zero to up ?adding diode can be a solutin?
@@CuriousScientist im pretty sure i didnt made mistake as long as i know it doent matter vcc and gnd of pot only signal pin middle one is important
As long as you are sure about the position of the wiper, you are safe. It is just that sometimes the wiper is not the middle pin but people assume it is the middle. If you flip the VCC and GND you just flip the limits, so you go instead of MIN to MAX to MAX to MIN when you turn the potentiometer clockwise.
Regarding the zero output voltage, there is no workaround. This specific (SZBK07) DC-DC converter has a minimum of 1.215 V output voltage when everything (the two potmeters) is at 0. This is how the LM25116 buck controller chip works. You need a different circuit if you need that 0 to 1.215 V range.
Hi, i have this module, but I can't change the current via cc pot. It's always at max i think. Do you know why us that?
Also i have a transfer which output after rectification is 44v. It's 4v more than recommendation. Is it ok if i use that transformer?
Hi! Don't use higher input voltage than the recommended. Use another converter which is compatible with such high input voltage. Regarding the current, you might just need to turn the potentiometer a lot. These are multiturn potentiometers and sometimes they don't cause any sudden changes. But as you mentioned that you "think" it is alway the max. Did you do any measurements?
@@CuriousScientist no i didn't do any measurements. But i tried to test it with a 12v/60w car lamp which the CC pot didn't dim the lamp.
I only have this 120w transformer with 30v ac output which after rectification it's around 42-44v dc
I'm planning to make a diy powe supply with this module using my old transformer.
I think i should change pots with 100k volumes like you did so maybe fix my cc adjustment problem.
But if you haven't done any measurements, how do you know? You can't just assume things. If your transformer provides 42-44 V, DO NOT use it with this module. Also, I guess you want to dim a halogen lamp, and in that case (as far as I know) you cannot just cut down the current. You have to chop the input voltage; so by changing the duty cycle of the voltage provided to the bulb you can change the brightness of it. So, you need a dimmer circuit and not an adjustable power supply.
all I know is my 20A version came with it's CC set higher than the board could take and pulled a good 50A blew up my 480watt power supply and toasted the chargers board , even tho I set the voltage close the battery bank voltage I was going to use it to charge , second attempt fuses instantly blew , Third attempt I set the Voltage lower than the battery then turned up the voltage until it drew power then I must have spun the CC a good 20 turns before it affected the power draw then bumped up voltage then bumped up Current until I finally got it doing the 12A max load I wanted , does anyone know the calculation needed to work out the resistance so I can just swap over the trim pots for a resistor that will do the CC I want ? I have 26 of these I need to do , just need to step up 12v to 48v for 150watt loads , and never want it going over 15A
You can find all the formulas in the datasheet of the buck controller chip.
Hello and thanks for this tip. I have a buck booster which has LM2577 and LM2596 (limiter and booster). It has a 3296 trimmer which i changed with a 50k pot. It works but when the pot is off, no voltage, when I turn it %20, it fires up quickly to 26 volts. So after %20, pot is useless. I tried changing 1-3 to 3-1, but pot is reverted. Also changed to 100k pot but still either same. I hope, i can explained correctly, 😔 sorry.
Hi! You should always replace the removed potmeter with the *same* value and ratings. I have never modified with the above mentioned converters, so I don't know why they misbehave.
hello a doubt in place of the potentiometer of 100k can I put the 10k?
Yes and no. I haven't tested it this way, but since you change the current running towards the FB pin, you would miss the 10k to 100k part of the resistance. Which means that you could not go below a certain values in current. That suggests me that you would not be able to control the output voltage on the full scale. I could actually test this. It is too late now, but tomorrow afternoon I will look at it on my circuit.
@@CuriousScientist so I bought the 10k multi-turn potentiometer and installed it on the disconnected and discharged plate more when I called it doesn’t work the plate is burnt I put the original pots and nothing burns the plate, but now I don’t know why and I’ll have to buy another unit and I fear it is for because of the 10k pots I put
@@igoragamenon389 I don't know if you followed my recent videos, but I tried it with different potmeters down to 1k and I explained what is happening. My circuit survived the whole test. It even survived that I removed and replaced the potentiometer while the unit was powered. So, I think either you got a defective product or accidentally shorted some sensitive connections.
I believe that there was a short or defective plate because I just changed the potentiometer and stopped, I really appreciate your help and congratulations for the videos.
Thank you! Let's hope that the future modules will not break down and will serve you for a long time!
The 20A module that I just bought didn't work at all, initially it turned on but the volt and curent couldn't be adjusted, then now it's completely dead, please help, what should I fix ??
If it doesn't work without any modification, then just send it back to the shop where you bought it and ask for a refund.
Hello, the voltage can be adjusted in my product, but current limitation cannot be made. What could be the reason, do you have any information? Thanks.
Hi! Are you trying it with the original potentiometers or have you replaced them? If you replaced them, make sure that they are the same value as the original, and also make sure that you soldered them properly.
@@CuriousScientist hi, i used it with original potentiometer. I thought if it was broken. i replaced it with another 100k potentiometer but the result did not change. potentiometer works but I cannot limit current.
It can be a faulty product then. I tested a brand new product which I unpacked literally 10 minutes ago and I could not limit the current at all. Unfortunately these cheap products are not always reliable. You might want to remove the mosfets and test them but maybe it is easier to just buy a new one and hope that it will work.
@@CuriousScientist the product I have is working. it only does not work at low currents. The potentiometer is very sensitive, very difficult to understand. The 100k potentiometer must have adjusted all the settings in the first round. Thanks so much
Yes, the CC side is very sensitive. Some time ago, I replaced the CC potmeter with a 8-bit digital potentiometer. Up until a certain value it worked OK, and then after just one step (roughly 39 Ohm change), it went bananas... I also still need to learn a lot about these buck converters. If you are interested, I recommend you to read the LM25116 buck controller's datasheet. It has a ton of information, but it takes time to digest everything.
Hello, are the pins of the voltage trimmer shorted? I used 20k potentiometer and burned when i turned it Completely.
Hi! Not shorted, it is used as a rheostat. I provided drawings on my website, check them. Also, you shouldn't use it with smaller than 100k potentiometer. Nevertheless, it should work with it. I have another video where I tested it with different potentiometers and I did not have any problems.
I tested the 3 terminals using multimeter where the trimmer was located. Found out that pin 1 and 2 has a continuity. How did it happened ? I just removed the trimmer
Have you read my previous comment? The CV potentiometer is used as a rheostat. Of course one of the pins are tied to the wiper of the potentiometer.
Would this modification also work for regulating the output of a boost converter?
I don't know. I need to see the circuit to know it.
@@CuriousScientist Hi. The circuit would be exactly equivalent to yours, except substituting the BUCK converter for a BOOST converter. Everything else would be the same i.e. taking off the blue CV potmeter and connecting a more ergonomic component etc.
Then I guess, it should work. But since I have never tested other circuits, I can't say with 100% confidence.
Buck converter not working how repair
It is very common that the mosfets give up. Remove them and check them with a transistor checker.
which one is better to buy green connector or black connector?
Hi! I would go for the green one. It has better quality.
@@CuriousScientist what is the issue you faced with the black one?
can you share your experience please?
The connectors seem to have a little lower quality. Also, the capacitor at the potentiometer is directly soldered on the pins and it does not have a dedicated location on the PCB as in the case of the board with the green connector. But you should watch the video, because I tell everything there. :)
@@CuriousScientist Is there any performance difference? this is the last question😊
@@userlevel61 :D There are no performance differences. Both of them are the same, they just (I assume) come from different manufacturers. The parts are identical everywhere, except the C15 capacitor which I mentioned above.
please make a video about 20amp buck converter with buzzer for short killer 🙏🙏
Sorry, but I don't make videos on requests. Also, I don't really understand what "buzzer for short killer" is.
@@CuriousScientist the buzzer work when you short the -.+ of output
I see! I am not planning to make any similar circuits in the near future but I will keep this idea in mind.
Very nice. Thank you very much
Thanks, and you're welcome!
Excellent tips
Thanks!
Witam zrobiłem zwarcie na wyjściu na minimalnych ustawieniach napięcia i prądu,co mogło się uszkodzić. Dziękuję
I have no idea what you said.
I made a short circuit at the output on the minimum voltage and current settings which could have Bern damageo .thank you
Thanks for translating it. I don't know what could have caused it. If you used the same values and parameters, it should work fine. I use this kind of setup for 2 similar DC-DC converters for making a 12 V 30 A PSU into a 2-channel PSU and they work just fine even at high loads. Some potentiometers, especially those very cheap ones are not really reliable, so they might break during usage. Once I made one spark and burn out. I recommend using some better quality potentiometers, especially for the CV potmeter as that potmeter experiences the whole output voltage.
I don know if IT matters, but event the LED on the inwerter input od not litano the power supply is potentiometers arę 100ohm 10 rotatong 2 Watts everrything was working before concluding.
The original potentiometers are 100 *kilo*Ohms, and not 100 Ohms. This might be the issue.
Would like to share a video and email between myself and a vendor that I would like to have some input on. Non peltier related
Also watch this video starting at 2:03. You'll understand when you see it. Also at 5:42
Feel free to message me on my instagram! I do not use any email address at this point because I haven't yet made a business email.
@@CuriousScientist sorry. Dont do Facebook or Twitter or Instagram or any of those social media platforms. I hate Google just as much but since they own TH-cam and the rest of the world there isn't an easy way to distance myself from them without distancing myself from the whole world. Although the internet is the best advancement in history I feel our lack of privacy is equally as big of a setback
some Modules have a Fake LM25116 if you Put a Potentiometer 100% will burn the Chip by this Video a lot people they will burning the Module :)
So far I haven't had any issues with replaced potentiometers. Also, people buying fake products is not my responsibility. Whenever I know about it, I always notify the viewers about quality issues (like I did for this circuit and for Peltier coolers), but in general I cannot really control these things.
@DIY Jaki: Thanks for the info, i want to buy this modules for solar charger.
I hope, i dont buy the Fake one
I have bought 2 time of this module...after i change pot trimmer to VR used only few minute smoke goes out on VR...after that dead..SmD chip burn...3 time i bought again this time i not modify anything with timmer pot to VR keep original...unti now everything steady Ok...solution is better keep back original part...
Sorry, but I have difficulties understanding your sentences. If your device breaks after replacing the trimmer to a normal potmeter, you probably did a mistake with the wiring or something. Pay attention to the connections and to the pin assignments. Some potmeters have different order of pins. I use my modules with replaced potmeters very often and they are still working. Some of them are 2-year old.
it won't last more than 7 days , multiturn trimpot have better accuracy .
I don't understand how you connect the longevity with the accuracy... And why 7 days? By the way, I have a video where I rebuilt a similar circuit with multiturn potentiometers. When I made this video, I only had these potentiometers.
@@CuriousScientist this potentiometer sprak inside and kill it then 50k becomes xyzM ohms , i hope you'll get it
Sure, I get it. I've been using several DC-DC converters with these potentiometers for years without issues. I had only one potmeter blowing up while I was tinkering, but I must say that they can be sometimes garbage quality. So, as long as you have good quality products and respect the tolerances, they work just fine.
@@CuriousScientist yaa but in my whole life didn't get any 360° turn potentiometer good 😔 , always i have to buy thise expensive multiturn potentiometer
Sir what is the min input current needed to produce the max output current?
It is a buck converter, so you need at least the same current and preferably 20% more voltage (efficiency) than the desired output voltage. Based on your question, you want to get a boost converter. With such a converter, you just need to make sure that the power in is about 20% more than the power out (efficiency), but you can almost arbitrarily combine the output parameters.