I have a 1U computer power supply here I was checking out. It is ABLECOM SP423-1S 420 watt supply. The circuit board is labeled FSP500-80BU Rev:1. I was wondering if it is possible to improve the efficiency of power supplies? I measured an input power of 404 W for an output power of 317 W into a resistor load. That works out to 78 %, not terribly bad, but maybe it could be improved? That's still wasting 87 W of power.
I noticed that the primary and PFC transistors seem to be the hottest components after load testing. That's not scientific measurement of power lost, but maybe these transistors could be replaced with better ones? Has anyone tried efficiency mods to power supplies? What were the results? Is it worth doing?
On this 1U supply the PFC transistors are two Infineon SPW20N60S5, rated 600V, 0.19 ohm, and 20A.
The primary switching transistors are two IRFP22N60K, rated 600V, 0.24 ohm, and 22A. I wonder where most of the power is lost, in conduction losses or switching losses? Or could other components be optimized?
Searching on Digikey, I found some transistors that are better in spec, with Ron of 0.075 - 0.09 ohms and faster switching times. But, they cost about $12 each. heheh. I'm not sure I want to spend almost $50 on an old power supply. But I am tempted to do this as an experiment. Comments?
I noticed that the primary and PFC transistors seem to be the hottest components after load testing. That's not scientific measurement of power lost, but maybe these transistors could be replaced with better ones? Has anyone tried efficiency mods to power supplies? What were the results? Is it worth doing?
On this 1U supply the PFC transistors are two Infineon SPW20N60S5, rated 600V, 0.19 ohm, and 20A.
The primary switching transistors are two IRFP22N60K, rated 600V, 0.24 ohm, and 22A. I wonder where most of the power is lost, in conduction losses or switching losses? Or could other components be optimized?
Searching on Digikey, I found some transistors that are better in spec, with Ron of 0.075 - 0.09 ohms and faster switching times. But, they cost about $12 each. heheh. I'm not sure I want to spend almost $50 on an old power supply. But I am tempted to do this as an experiment. Comments?
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