My transformer was salvage from a piece of fully functional audio/visual equipment, has a center tap , 28/28 ,9/9, and 7/7..Which gives me 56/18/14 volt respectively. 18 gauge wire in and out ..I suspect the most this transformer can safely produce is 5 amp.
I looked about the components in the schematic and found that 56 volt isn't leaving much overhead in some components.Though I would like the extra 28v ..comments?
There is another place on the schematic where two values are shown for a resistor.In the schematic there's reference to (r5) 2k2 and a 1k on what i believe is a current sense resistor.
im currently using the 2k2.on the output +
.whats the difference between one or the other?
No, that does not seem to be at all correct.There's also a a cut limit switch ,In cut mode the p/s immediately cuts any output , with nothing hooked to it. don't think that's right.
P5 is the current sense resistor for the ammeter, and the current limiting circuitWhat's the purpose of P5 in the ammeter arrangement?
?? Why do you say that? the current limiting circuit should also provide short circuit protection.also ,im not big on the idea of only having a fuse as short circuit protection..
Then the current limit circuit does not work well.
It should protect the supply at all settings of output voltage and current limit.
JimB
56 volt input is way too high. The power dissipation will kill you and the power transistors can't handle this (look at SOA curves)So Im building my own power supply based on this unit and schematic here:
My transformer was salvage from a piece of fully functional audio/visual equipment, has a center tap , 28/28 ,9/9, and 7/7..Which gives me 56/18/14 volt respectively. 18 gauge wire in and out ..I suspect the most this transformer can safely produce is 5 amp.
I looked about the components in the schematic and found that 56 volt isn't leaving much overhead in some components.Though I would like the extra 28v ..comments?
The pot in the schematic appears to be a 1.5 ohm unit. If you have 50 ohms it's not surprising that you have difficulty setting the limit to a desired value.T........................
crutschow/JimB
P5?
Yes I did put the pot in I used a 50ohm Multi Turn. I had noticed that the limit was set real low on one end..no current at all..to the high end..lots of current.
So that makes sense. There's a sweet spot I just have to find it.
Yes now that Ive messed with P5 a little,The current limit works....
But the cut I had thought was intended to "cut the current and voltage upon a short "
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