XL4016 Buck Converter Reverse Engineering & Repair
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- Опубликовано: 11 окт 2024
- In this video I reverse engineer a constant current constant voltage (CC CV) buck converter based on an XL4016 chip from XL Semiconductor. It was a cheap module from ebay, and it wasn't working properly when I received it.
I figure out (and explain) how it works, and what I think is wrong with it. In a follow up video, I will modify it and run some tests to see if we fixed it.
![[Natalex] Мощный понижающий DC-DC преобразователь XL4016 "DC-DC CC CV Buck Converter"...](http://i.ytimg.com/vi/XVd_tkK5BJE/mqdefault.jpg)
![[Natalex] Мощный понижающий DC-DC преобразователь XL4016 "DC-DC CC CV Buck Converter"...](/img/tr.png)
I bought one of these modules XL4016 and noticed an awkward CC behavior. Maybe your review is close to the problem. Thanks for sharing and I will see your other videos, but didn’t want to leave you without this first-impression feedback.
Beside the great explanation the schematic you draw helped me to find the fault and repair mine module. It was the via point from 10k pot to out + rail, it has a no contact with both sides of board. Thumbs up and keep the good work.
Hey man, I am a beginner. I ordered it and made a power supply. In my supply, I am unable to limit current below 5amp. What shall I do
The regulator is needed because if you don't include it, the current limit would depend on the input voltage, and that is not good.
With a couple of external components (by injecting current into the feedback pin), the output voltage of this module can be modified by a microcontroller, so it can be used it as a controlled variable voltage source.
you are right.. there is one ceramic capacitor there. Your reverse engineering looks great though. If you want I can measure it and give you the capacitance as soon as I have time for this. 😀 in my board there is a capacitor where in yours we have nothing.
Thanks for the detailed schematics.
5:52 Red indicator for high current on my device doesn't glow. I've tested the LED both color work(Blue at 2.25v and Red at 1.8v). When current is high both blue and red side get 0.8V so nothing lights. Is the op amp or the mosfet faulty?
The 4007 mosfet near opamp fell off during shipping.
Regarding capacitor - voltage rating and capacitance - I know that ripple currents increases as voltage rating goes up, but we would need to check those two (35V 1000uF ; 50V 470uF) who has the highest i_ripple.
Can you help me, in my module I am unable to limit current. My potentiometer is fine. What could the problem be
Hey, the capacitor on the opamp's output is there to prevent oscillation when the system is about to reach equilibrium. They might have miss calculated it's size and were slowing the response down too much.
Thanks for your comment! I had a good think about this and I see where you're coming from. As frequency increases, capacitive reactance decreases, reducing the gain of the amplifier. And I think that effect would tend to stabilise the power supply under step load conditions, which is good. However you're also introducing a phase shift into the negative feedback network, which is a huge red flag for me unless you know exactly what you're doing. It is just begging for the system to oscillate.
I really don't like using op-amps in open loop mode, I much prefer to use a comparator for those kinds of jobs. In this case, I would want some fixed gain in the control path, which would tend towards unity at some upper frequency which I would determine from the nature of the load. It is a trade off between reaction speed and stability. They clearly got it wrong from the oscillations I was seeing. I ended up putting a resistor and a can in parallel, which worked very well.
@@alexwood020589what is capacitor
does it need a free wheeling diode while using a motor as load?
I bought 4 and the 4 are faulty the trim pots does nothing it simply outputs whats in ... im not able to down the voltage
Bought this board in 2020 and it seems few errors where fixed.
Not to sure about those bulk caps though, the 50V ones are on the switching side, and switching always leeds to voltage spikes, i guess that's why they have 50V ones there instead of the input.
The input in this one is supposed to be "happy stable current"
Dit you end up switching those? any luck for your application?
This module is a buck configuration, so there is a chunky inductor between the switching node and the output caps. The node with the caps connected is the output voltage, which is smooth (ish) DC at a lower voltage than the input. There is a freewheeling diode on the switching node too, so it will switch between 0V and the input voltage + 1 diode drop.
Generally with a buck converter you want small value, low impedance, high voltage caps on the input and very large value, lower voltage caps on the output. I did swap the caps around, and replace the op-amp in the constant current circuit with a better one. Check out my channel for part 2 where I do the mods and test it.
Previously I have watched your video but now I am not able to get on youtube please share the video link for the DC-DC boost converter 600W, please share the link
Thank you for the schematics and the door for repair
I have same module. In my case potentiometer not work for voltage and current. What would be solution. Module is working but not adjusting volatage and current
Try to turn pots other way they can get stuck if you over turn them only on one side
please share the video link for DC-DC 600 W boost repair video
Hi, Great work. Did your modification work? Is there a followup video for the same?
Hi,
Check out my channel for part 2.
In that one I make my modifications and test them out. It worked a treat, and this power supply has been doing good service driving the peltier in my beer cooler.
I cant find your part 2 video is it public? Nvm found it!;)
@@alexwood020589 this module came cheap from AliExpress for 2$ shipped to India , it worked fine for a few minutes then I switched off for few minutes and went for a break then turned it on back again and it's not going above 2 volts and its not able drive any load😓. Then I landed here on your video on how to repair it. Gotta see your work mahn! I hope I can revive it back to life 😓. Your help will be greatly appreciated 😇 my email is talktoalokd@gmail.com
I got this same module and i am facing issue where the amp is not really getting regulated. When i short the output with amps knob fully down it still outputs the same input amps and when i try to lower the amps it goes to minimum but once i add more load the voltage drops to 3v and stay there and amps keeps increasing somewhere to 1.2 amps.
How should i fix it? Any idea?
Same problem
At 8A, the diode gets pretty hot. Maybe dropping 0.52v. That's 4 watts. You'd need meaty tracks and a big diode package to sink that sort of heat. If delivering to a low V load, you'll find the diode gets somewhat hotter than the XL4016. I'd prefer to see the heatsinks moved right to the back of the board, giving the electrolytics more ventilation. But that would obscure the screw holes.
Hi,
Thanks for checking out my video.
The main output diode is in a TO-220 package mounted on one of the big heatsinks, so it can handle significant power dissipation. The diodes are actually rated for something like 25A each, and there are two in parallel. I suspect the thermal resistance from the diode junction to the heatsink (including the TO-220 package, thermal grease and the annodisation on the heatsink) is between 1 and 2 degrees C per watt. A heatsink that size has a thermal resistance to ambient of around 4 C/W (according to the datasheet for some similar ones on Mouser). So I'd expect the die to be around 6C per watt higher than ambient worst case. So under 4W of load, the die is likely to be around 55C or lower.
You're right that the electrolytics are a bit close to the heat sinks for comfort. With modules this small (and cheap), its hard for them not to be.
There is a really good article on designing heat paths from chip dies to ambient under different load conditions below. I have found it very useful when designing power electronics.
sound-au com/heatsinks htm
my module has problem that current can't go up. just can run 100mA. voltage is ok. just current. sorry for my english. hope you can help me to solve this
Thats depend on your input
I think I damaged my module.what I did was I used a boost converter to step up 12v to 30v and then input it to buck converter same as in video,what happened was the voltage it was showing was 40v and the caps popped and now it stopped working and I am getting same voltage as input in output and I can vary the voltage using pots.pl help!!
I'm afraid that is probably a dead module! I expect it would actually cost you more to buy replacement parts than it would to buy a whole new module. I suggest you start with just the boost converter. Power it up with nothing connected to its output and use a multi-meter to set its output voltage, I suggest no higher than 33V (the absolute maximum the XL4016 can handle is 36V). Once you are happy the boost converter is working, connect a new XL4016 buck module to the output.
@@alexwood020589 that worked!! Thanks
i accidently input 50v to input now its not regulation voltage i mean not adjusting output voltage pls help me.on output its give what i input .
Hi
I expect at the very least you'll have to replace the XL4016 chip. The over voltage has most likely destroyed its main switching transistor, so it's just conducting from output to input. It's also possibly that the voltage destroyed the linear regulator powering the feedback circuitry. Only way to know is to start replacing parts.
I suspect it would be cheaper to consider this module a lesson you had to pay for, and just buy a new module.
@@alexwood020589 thanks for your time,i really appreciate it.
Good job man 👍
You are getting all WRONG here: the Caps and Inductor are NOT filters, actually the inductor is the main component to store the energy when XL4016 goes on. That energy gets discharged when XL4016 goes off, the caps store the the charge ("
reservoir" and not filter) and most important is MBR20xx since all the 8A load current flows through it...MUST be on a large heat-sink can't be replaced with some small SMD as you have said.
Hi
You're right that the inductor and capacitor store energy while the switcher in the buck converter is closed, and release it while the switch is open.
I would argue that is the basics of how all LC filters work though, whether that's for RF energy, small signals, Class D amplifiers or switching power supplies.
My aim with this video was to help people understand how this power supply works, and I find the explanation that the switcher creates a square wave and the LC network filters it to DC far more intuitive for a beginner.
@@alexwood020589 Maybe you are from a very-old-school... your errors here can 'confuse'many young learners. This Electronics Project here has nothing to do with "filters" . NOTE: a smoothing circuit can't be classed as a filter in Modern Electronics. Technically a filter is a circuit which allows a band of frequencies to pass through while blocking other frequencies. The passed frequency is called "bandwidth" and the center frequency is given by a formula of f0= (1/(2*pi*sq-root( L*C))). where L is the inductance in Henrys and C is the capacitance in Farads. You learn this in any university in USA in semester 2 of Electronics Degree. You are mixing things up here where as Technology and Engineering now have specific meanings for technical terms unlike other general fields such as arts or business. Though you are trying to help here BUT your many ERRORS in explanation is doing more harm than good.
Schematic diagram please
In same converter im not getting output
Same board led not blinking
How to modify the circuit that 1.25V to 0.1V
@Shankar did you find the way? i have same question with you
@@pegasus5401 No
Still can't find.
@@ShanVijay007 After i look the datasheet, i think because XL4016 is need minimum of 1.25v to operate normaly
@@pegasus5401 ohh ok bro
Thank you bro
Sir Mosfet Nambar???
I-adjust not work, what that?
seems it is designed as lithium battery charger, cuts off as designed I guess, you can see video here of use as charger
ruclips.net/video/4Iey_qXxAmk/видео.html