I replaced all the caps in the Panstar 230W AT power supply (for the FIC VT-501 Pentium system I mentioned in another post) with Panasonic EB and FC parts. Nothing was obviously swollen or visibly degraded, and the two major filter caps were HEC. The power supply works just fine.
My question has to do with the design of the AC input side, which I imagine is not very different in an ATX supply. There are jumpers installed in place of where LF1 could be. The following parts were not originally installed: LF1, C1, C2, C3, C4, and R1. C3 and C4 have since been added (0.0047uF, 500V ceramic disc) to provide RF filtering. R1, I'm guessing, is to discharge the L-C network, and could be 100k to 1M, so as to not load down the supply. C1 and C2: polystyrene or other non-polarized caps? The board has an outline for LF1. Is this usually a single part, or two separate coils? Recommended values? I'm not sure these parts are really needed, as the power supply ran just fine without them for several years. I'm curious more than anything.
Also, what is the purpose of the 1-ohm power resistor in series with the input fuse? It's mounted on end, so one of the two leads isn't accessible from the top of the board. I'm thinking that it was for testing, to monitor the input current when the board was being tested at the factory, although it's not a precision 1-ohm resistor, so the voltage developed across it would depend on the line voltage as well as the resistor accuracy.
My question has to do with the design of the AC input side, which I imagine is not very different in an ATX supply. There are jumpers installed in place of where LF1 could be. The following parts were not originally installed: LF1, C1, C2, C3, C4, and R1. C3 and C4 have since been added (0.0047uF, 500V ceramic disc) to provide RF filtering. R1, I'm guessing, is to discharge the L-C network, and could be 100k to 1M, so as to not load down the supply. C1 and C2: polystyrene or other non-polarized caps? The board has an outline for LF1. Is this usually a single part, or two separate coils? Recommended values? I'm not sure these parts are really needed, as the power supply ran just fine without them for several years. I'm curious more than anything.
Also, what is the purpose of the 1-ohm power resistor in series with the input fuse? It's mounted on end, so one of the two leads isn't accessible from the top of the board. I'm thinking that it was for testing, to monitor the input current when the board was being tested at the factory, although it's not a precision 1-ohm resistor, so the voltage developed across it would depend on the line voltage as well as the resistor accuracy.
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