[sdiy] Load testing dual PSU

blacet at blacet.com blacet at blacet.com
Mon Nov 3 16:28:00 CET 2014


A few calculations with Ohms law will do the trick. R=EI

W=EI will give you the minimum resistor wattage. I tend to use cheap ones
from Mouser in the white ceramic housings. I also use 2X the minimum power
to avoid them getting really hot.

I will string a few of them together as required to get the necessary ohms
and watts.



> Hi Roman,
>
> Thanks for the confirmation. In fairness I probably just need to get some
> higher power resistors. For some reason I had it in my head that they
> would be hugely expensive. I think I was picturing massive heavy ones that
> I remember from college. I'm sure they aren't as expensive as I thought.
>
> P.S. Friend request sent. I'd like to see the photos of that's okay.
>
> Cheers
>
> Rob
>
>> On 3 Nov 2014, at 12:49, Roman Sowa <modular at go2.pl> wrote:
>>
>> hi,
>> actually I use both :)
>> A string of 1 ohm 20W resistors, about 15 of them, so I can adjust load
>> resistance with banana cable by clamping part of the string. And there
>> is also G4 socket with soldered across part of the ladder, so I can see
>> if there's heavy current flowing or not witout looking at power supply
>> Amp meter. This is usable when testing switching circuits. I plug there
>> 5W, 10W or 20W bulb depending on needed load capacity.
>>
>> It get's hot, no matter what you do, just learn to live with that. Not
>> really pssssst hot, the resistors get nicely warm/hot after some time at
>> 3A.
>>
>> Your temperatures will stabilize in manner of minutes, not days, so
>> unless you are doing burn-in test, there's no need to leave it on for so
>> long.
>>
>> Roman
>>
>> PS for my Facebook friends, few hours ago I posted a picture with the
>> load fixture described here.
>>
>>
>>
>> W dniu 2014-11-03 13:24, Rob Spencer pisze:
>>> Hi,
>>>
>>> I've recently developed a +-12v PSU, with +5v and post voltage
>>> protection and am looking to do some load testing. I know I could
>>> stick a low resistance across it but that's going to get very hot
>>> very quickly. The other thing I'm thinking is to place some 12v light
>>> bulbs across the rails and leave it running for a few days with
>>> temperature monitoring in place on the voltage regulators.
>>>
>>> I'm wondering how other people have tackled this in the past.
>>>
>>> Cheers
>>>
>>> Rob _______________________________________________ Synth-diy mailing
>>> list Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
>




More information about the Synth-diy mailing list