Gooday all,
I have got two of these units, both had a lot of dry joints that I have re flowed. They are adjustable between 45-54VDC. One is working OK, the other cannot adjust at all and sits on 36VDC on the output. Might be some more dry joints or a faulty adjuster. There are two pots, one is for voltage and the other sits next to a CD4069ube chip. I do not know what it adjusts but I'm leaving them alone. Any idea what the VA of these units might be and are they usable for diy amplifiers.I have not worked on smps's before, I know there are high voltages and to discharge the caps before working on them.🙂 Help appreciated !
I have got two of these units, both had a lot of dry joints that I have re flowed. They are adjustable between 45-54VDC. One is working OK, the other cannot adjust at all and sits on 36VDC on the output. Might be some more dry joints or a faulty adjuster. There are two pots, one is for voltage and the other sits next to a CD4069ube chip. I do not know what it adjusts but I'm leaving them alone. Any idea what the VA of these units might be and are they usable for diy amplifiers.I have not worked on smps's before, I know there are high voltages and to discharge the caps before working on them.🙂 Help appreciated !
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Ok , got it fixed, dry joint on a TL431, so I have two working 100%, but still do not know the VA , I suspect 300-340VA, well, I'll try them sometime. Negative is nowhere directly connected to earth, only via a 3nf cap for noise filtering, so they should be OK to connect +- to give +-50Vdc.
I've seen substantially bigger heatsinks in 250 W ATX PSUs... I'd say this one might be about 150 W given decent ventilation. OTOH, 2x 330 µF is quite a bit of primary capacitance, and magnetics aren't small either. In audio use, the onset of overcurrent protection may be of more interest than actual power capabilities - current draw of an audio power amp is far more variable than in what these telco supplies were originally designed for. That's traditionally been the crux with SMPS, they tend to just shut down on current peaks that a transformer would have grudgingly supplied.