I was using this supply with the fix applied in short bursts with low voltages and it was fine. Today I need 15 V and a very little current (basically open). Well, after ~20 minutes I smelled a typical burnt electronics smell. The disassembly of the unit shows that those resistors are burned up. So the fix does not seem to be very robust. My version of the PCB is different, but the capacitors are located in the same place and the transistor has the mentioned trace.
Recently purchased one and the board has been redesigned. Mine still powers down slowly but to -0.1v rather than -0.6-0.7 and one of those 3 caps (the left most one) has been replaced with a resistor. There is no fan screen print but the 2 transistors in that location are still there but side by side so no idea which I should remove....
Interesting would be also a second AC power connector for a second power supply without the need of an other wall socket. So you can use 1,2,3.... power supplies and have a clean mains wiring.
You could add an external C7/C8 power switch. Ebay has them listed as "Power On Off Switch Adapter For PS3". Did you find out a way to power it with DC?
Great video! For the modification regarding '0V correction' I unfortunately can't vouch (in my case). On my pcb it says "MPL3050A V5.5 - 2015-08-06" and it is optically absolutely the same (position of parts, "FAN" lettering etc. as shown) - I removed the transistor and replaced the two caps. Effect: The new resistors (also 47ohm by chance) vanished into electronics heaven. The apparatus still works, I simply de-moded it again. Just wanted to say: Be careful.
a hundred bucks for a SMPS and then i need to mod it and invalidate the warranty, here is an idea , dont beta me , design a product get James to test it and don't use us as Guinea pigs , im out, thanks for the review James, love your #AddOhms @Addohms channel, i really thought with the channel name you would have been called Adam like Adohm, lol
Death by a thousand papercuts, I don't think it's a winner for me. Though I do love the form factor. It's: $100, noisy, bugged, no switch on mains input, poor quality accessories in box, unreliable specs.
What happens when you set a current limit of say 100mA and attach it to something like a 1 ohm resistor? will it be able to regulate down to 0.1V(since the minimum voltage is 0.3V) or would it just go over the set current limit?
It shuts off, but not how I'd expect. I measured it on my scope. You can see it on the element14 page: www.element14.com/community/docs/DOC-92326/l/workbench-wednesday-08-affordable-hand-held-power-supply-review#comment-155128
As there are no screw terminals, I'd reccommend the Wago 4mm spring-terminals (
p/n 50077010 and 51174966 ) as a quick way to connect wires.
I was using this supply with the fix applied in short bursts with low voltages and it was fine. Today I need 15 V and a very little current (basically open). Well, after ~20 minutes I smelled a typical burnt electronics smell. The disassembly of the unit shows that those resistors are burned up.
So the fix does not seem to be very robust. My version of the PCB is different, but the capacitors are located in the same place and the transistor has the mentioned trace.
"the datasheet is optimistic" that's not acceptable for test equipment. 100mV/p-p is terrible for a test psu
Recently purchased one and the board has been redesigned. Mine still powers down slowly but to -0.1v rather than -0.6-0.7 and one of those 3 caps (the left most one) has been replaced with a resistor. There is no fan screen print but the 2 transistors in that location are still there but side by side so no idea which I should remove....
I would need the display to show actual current and voltage at all times, not have to press that V/A button.
I’d like to know if I could put two of these in series to create a +/- rail supply.
Ofcourse you can
karlpc200 are you sure? Some supplies can be damaged by doing that. I would expect a good quality supply to be fine but some aren’t.
It's isolated and doesn't even has a ground in the ac cable, so it should be OK.
@@reddragon27284 As long as it is galvanically isolated from the AC supply it shouldn't be a problem
Interesting would be also a second AC power connector for a second power supply without the need of an other wall socket. So you can use 1,2,3.... power supplies and have a clean mains wiring.
Really neat power supply, in such a small package. Powered by STM32 :)
You could add an external C7/C8 power switch. Ebay has them listed as "Power On Off Switch Adapter For PS3". Did you find out a way to power it with DC?
Great video! For the modification regarding '0V correction' I unfortunately can't vouch (in my case). On my pcb it says "MPL3050A V5.5 - 2015-08-06" and it is optically absolutely the same (position of parts, "FAN" lettering etc. as shown) - I removed the transistor and replaced the two caps. Effect: The new resistors (also 47ohm by chance) vanished into electronics heaven. The apparatus still works, I simply de-moded it again. Just wanted to say: Be careful.
a hundred bucks for a SMPS and then i need to mod it and invalidate the warranty, here is an idea , dont beta me , design a product get James to test it and don't use us as Guinea pigs , im out, thanks for the review James, love your #AddOhms @Addohms channel, i really thought with the channel name you would have been called Adam like Adohm, lol
"My arm got better." doesn't show arm.... My conclusion, it fell off.
When the doctor asked how much pain I was in, I told her: "I thought about cutting it off. But my table saw isn't set up, so I came here instead."
Death by a thousand papercuts, I don't think it's a winner for me. Though I do love the form factor.
It's: $100, noisy, bugged, no switch on mains input, poor quality accessories in box, unreliable specs.
Will this output ac?
100mvpp noise,,, not for us,,, do u know of others w cleaner spec ,,, but costing less than usd300... cheeper the better
I dont like that form factor when working on the bench it just wouldn't stay put like a heavy bench power.
What happens when you set a current limit of say 100mA and attach it to something like a 1 ohm resistor? will it be able to regulate down to 0.1V(since the minimum voltage is 0.3V) or would it just go over the set current limit?
It shuts off, but not how I'd expect. I measured it on my scope. You can see it on the element14 page: www.element14.com/community/docs/DOC-92326/l/workbench-wednesday-08-affordable-hand-held-power-supply-review#comment-155128