Trying to convert a M2 silent pro PSU into a bench top power supply

Thread Starter

jacobth

Joined Mar 2, 2018
3
so I have a cooler master 1500W M2 Silent Pro PSU and it can deliver 12V at close to 100A. I am also in need of a variable power supply. so I'm wondering how to convert one into the other. I realize I'll have to replace components to withstand a higher voltage but other than that I'm at a lose.
 

MisterBill2

Joined Jan 23, 2018
7,259
so I have a acooler master 1500W M2 Silent Pro PSU and it can deliver 12V at close to 100A. I am also in need of a variable power supply. so I'm wondering how to convert one into the other. I realize I'll have to replace components to withstand a higher voltage but other than that I'm at a lose.
If you can find a copy of the circuit of the device then I can certainly offer some advice. But I don't even know what a acooler master 1500W M2 Silent Pro PSU is and so providing any assistance is difficult. I don't recognize many things by their trade names, except for a few things..PSU often refers as a Power Supply Unit, but that also is subject to interpretation.
 

Thread Starter

jacobth

Joined Mar 2, 2018
3
If you can find a copy of the circuit of the device then I can certainly offer some advice. But I don't even know what a acooler master 1500W M2 Silent Pro PSU is and so providing any assistance is difficult. I don't recognize many things by their trade names, except for a few things..PSU often refers as a Power Supply Unit, but that also is subject to interpretation.
I've have tried to get the schematic from the company but I'm still waiting and it's been a few months....
and its a computer power supply.
I can't find for it online which is why I came here since I know these forums are pretty good at problem solving.
 

MisterBill2

Joined Jan 23, 2018
7,259
I've have tried to get the schematic from the company but I'm still waiting and it's been a few months....
and its a computer power supply.
I can't find for it online which is why I came here since I know these forums are pretty good at problem solving.
OK, so now I know that it is a computer power supply! Now I can provide at least a bit of advice. Computer power supplies are very much optimized for powering computers and not for other applications. The newer ones provide +5V, +3.3V, +12V, and often also -12V, with a secondary always-on +5V output. Most of them also need some minimum level of current drawn from the main +5 volt line in order to stay on. Otherwise the over-voltage sensor shuts the supply off. So the typical conversion of a computer power supply to any other application includes adding a load to draw a few amps from the +5 volt supply. That load is typically a bank of low value high wattage resistors that will draw perhaps 5 amps, at least. In addition there is a control line that is usually grounded to turn on the outputs, except for some weird supplies where it gets connected to the standby +5 volt line. Some X-Box supplies have that arrangement.
Because the supplies use switching regulators, and because they are intensely optimized for certain outputs, modifying them for a different output would be a real challenge. But they can serve as good supplies for the rated output voltages if you add an external load to satisfy the minimum load requirement. Then all that you need to deal with is the waste heat from that load-bank. OR, you can use that power for lighting up the work area. All you need is enough 6 volt bulbs to draw 5 amps or so.
 

Dodgydave

Joined Jun 22, 2012
9,644
The atx psu can be made variable as i have done this several times.

You first need to find which chip it uses, then get the datasheet for it, it's a matter of disabling the overvoltage protection, then altering the feedback loop.

There are several chips in use today and all have a different protection setup.
 

mtonge

Joined Apr 19, 2016
92
I'm using a 500W supply on my bench to power my breadboards using jumpers attached to fan header adapters off the four pin Molex connectors. I'm using a PSU tester plugged into the ATX connector to turn on the supply and provide a bit of load. It's not pretty, but at least the cables are nicely sleeved. The wire colors are standardized: red is 5v, yellow is 12v, orange is 3.3v, blue is -12v, and black is ground. Spark Fun has a nice power board kit to break out 24 pin atx voltages. I'm ordering one of these now to clean up my work bench. they also sell an adjustable voltage regulator (LM317TG) and you may be able to make up a variable output terminal. There is a world of info out there.
 

MisterBill2

Joined Jan 23, 2018
7,259
I'm using a 500W supply on my bench to power my breadboards using jumpers attached to fan header adapters off the four pin Molex connectors. I'm using a PSU tester plugged into the ATX connector to turn on the supply and provide a bit of load. It's not pretty, but at least the cables are nicely sleeved. The wire colors are standardized: red is 5v, yellow is 12v, orange is 3.3v, blue is -12v, and black is ground. Spark Fun has a nice power board kit to break out 24 pin atx voltages. I'm ordering one of these now to clean up my work bench. they also sell an adjustable voltage regulator (LM317TG) and you may be able to make up a variable output terminal. There is a world of info out there.
The other comments are certainly valid and worthy of pursuit, I was just delivering the caution part. I don't have any information about your skill and knowledge set and I did not want to cause you grief by getting it wrong. From the projects that I have built, +5 and +12 would cover a whole lot of them, and so you could use the supply unmodified, easy and simple. Adding an LM317 adjustable regulator fed from the 12 volts output will give you the other voltages at 1 amp, and that should work with the rest of most experiments. But the very first thing to do, after finding which wire switches it on, is to add a load, and measure the outputs. If the outputs don't work then there are other problems.But you do need to have that minimum load or it will shut down instantly.
 

Thread Starter

jacobth

Joined Mar 2, 2018
3
I thought that their was a way to draw more voltage than 12v. I thought their was a pwm IC that controlled the duty cycle of a square ware that once rectified provided the 12v so if I could change one of the resistors for a potentiometer then I could control the output.
 

MisterBill2

Joined Jan 23, 2018
7,259
I thought that their was a way to draw more voltage than 12v. I thought their was a pwm IC that controlled the duty cycle of a square ware that once rectified provided the 12v so if I could change one of the resistors for a potentiometer then I could control the output.
Computer power supplies are true engineering marvels and very much optimized. Your very big challenge will be finding the place to adjust the output. If you can get an actual part number off of the control regulator then you will still need to trace out the circuit and make the connections. What could work fairly easily is using a linear regulator to drop the 12 volts down to some lower value.
 
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