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I have read the stuffing guide, studied the schematic and have been reading as much as I can about power supplies to try and not ask too dumb a newbie question.
What are the variables in the schematic that need to be adjusted for different sized/voltage transformers?
Lets assume a 300VA 35v dual secondary transformer.
To me it looks like,
- the obvious, the big main caps (C1..C4) have to be the correct voltage (i.e. 63v caps for 35v transformer)
- snubbers (CX, CS, RS) based quasimodo jig, or left out if using your LT4320 based active rectifier
- LED resistor (R10, R11), based on transformer voltage
My questions are about,
- the filter resistors, R1..R6 or RP1, RP2, it looks like it you use R or RP, but not both, when would you use one vs. the other, and how do you pick the values? R1..R6 are shown to be 1 ohm, is that a fixed value or does it change based on transformer? How many watt should they be and of what type? RP1, RP2 are shown as type BPR 56 5 watt resistors, but what value should they be if used rather than R1..R6?
- the Vishay PB3506, for what sized and voltage transformer are they good til? If and when would you need to go to PB3508 or PB3510?
- R8 and R9 are shown as 1 ohm 1 watt resistors, does the type matter?
- RB and RB' are shown as typical value being 2200 ohms, 3W for 35 volts. Is that typical for a 35v AC transformer or a rectified DC voltage of 35v?
- For the ground pad between the bulk caps, I looked around the Elliot Sound Products web site and didn't find the information about for connecting it to the chassis via a disconnect network, I thought this search would have worked "disconnect network" site:Elliott Sound Products - The Audio Pages (Main Index) . Does anyone have any direct links where I can read specifically about his?
Sorry for such basic questions.
David.
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Sorry, I don’t have many answers (I received my PCBs today and is just now reading through the thread to figure out how to build it), but I noticed that the schematic appears to show R8,9 to be 1 Ohm 0.25 Watt resistors. I believe either metal or carbon film resistor would work well.
