Cheap Generic PSU + Quality Components = Decent PSU?

[Elledan]

Random thought # 760398:

If you replace (some) of the components on the PCB of a cheap, generic PSU, will this kind of surgery turn this ugly duckling into something-which-might-be-a-swan-if-you-don't-look-too-closely?


Sorry

 

[[Spectre]]

But why?

 

[jonnyGURU]

Cost effective = No.

Profit?

And some PSU's are just horribly designed to begin with regardless of the componets used. Forget about it.

 

[Elledan]

But why?

Because some people end up with piles of POS PSUs and happen to be able to solder quite well. And they're bored enough to come up with such ideas

Cost effective = No.

Profit?

And some PSU's are just horribly designed to begin with regardless of the componets used. Forget about it.

Sorry

 

[larrymoencurly]

If any diodes or transistors are underrated, I'd upgrade them. I once saw a Deer PSU where the diode bridge was rated for less amps than the fuse, and someone posted a pictures of another brand PSU where an output diode was rated for 10A even though its votlage rail was rated for a lot more than that. But most of the cheapos I've seen had diodes and transistors with the same ratings as those in quality PSUs, except sometimes the good PSU would have a pair of them in parallel (but some better brands, like Enermax, also left out the second ones -- empty spaces for them). I read that if any missing second one is added that it should be exactly identical to the first one, in order to share the load exactly. OTOH the capacitors in cheapos are sometimes half as large, and the heatsinks can be really puny. Also if the cheapo has a jumper wire in place of the thermistor on the high voltage side, it should be added.

 

[Elledan]

If any diodes or transistors are underrated, I'd upgrade them. I once saw a Deer PSU where the diode bridge was rated for less amps than the fuse, and someone posted a pictures of another brand PSU where an output diode was rated for 10A even though its votlage rail was rated for a lot more than that. But most of the cheapos I've seen had diodes and transistors with the same ratings as those in quality PSUs, except sometimes the good PSU would have a pair of them in parallel (but some better brands, like Enermax, also left out the second ones -- empty spaces for them). I read that if any missing second one is added that it should be exactly identical to the first one, in order to share the load exactly. OTOH the capacitors in cheapos are sometimes half as large, and the heatsinks can be really puny. Also if the cheapo has a jumper wire in place of the thermistor on the high voltage side, it should be added.

That's what I was thinking (well, roughly ^_- ).

Of course, replacing underrated components is easy, actually improving the design (by adding 'missing' components and such) requires a lot more knowledge of switching PSUs. It definitely sounds like a fun way to learn more about this type of PSU, though

 

[HekoAridese]

And just for safety's sake, don't go crawling around in PSU's if you don't know what you're doing - the condensators alone could fry a finger or two, let alone what happens if you shortcircuited the thing since you didn't solder right.

 

[Elledan]

And just for safety's sake, don't go crawling around in PSU's if you don't know what you're doing - the condensators alone could fry a finger or two, let alone what happens if you shortcircuited the thing since you didn't solder right.

Your warnings come a few years too late it didn't hurt too much, though...

Let's just say that if I were to perform such a mod, I wouldn't put the PSU in one of my main systems ^_-


(they should've told me sooner that sometimes the heatsinks are 'live'... ouch )