hi i dont have enough parts at stash,run out of good transformers and hi curent regulators ,and in sort of hurry to finish amp.at +-45v dc is it better to drop 10v with 2sc1943, 2sc5200 or put them in output(dont care i need pair more i have stash) ,sort of using 3875 as first stage but on 94v still 😀 ? i know neither solution is good but i need to have spare amp in few days from now,so cant wait for parts to arrive.
i think is lot better to put in output but want to make sure i didnt miss something.
i think is lot better to put in output but want to make sure i didnt miss something.
Absolute maximum ratings are 94V rail to rail when no signal is present and 84V rail to rail when a signal is present.
Your measured 94Vdc may not be worst case.
How high could that go when mains is at it's highest?
I suggest that you build a non feedback voltage regulator using a Zener and emitter follower (Pass has examples) to bring your supply down to +-40Vdc, or lower.
A capacitance multiplier could also drop significant voltage to enable your chipamp to survive.
Your measured 94Vdc may not be worst case.
How high could that go when mains is at it's highest?
I suggest that you build a non feedback voltage regulator using a Zener and emitter follower (Pass has examples) to bring your supply down to +-40Vdc, or lower.
A capacitance multiplier could also drop significant voltage to enable your chipamp to survive.
+1
Here's a good intro to zener regulators: Voltage Regulators, Different types, Working principle, Design
Tom
it burned resistor on negative side, and for few seconds there was 1.5v on output. i cant find Pass labs version of this.
well managed to put 84 volts on -ve somehow, and burned both 3875 ,still not sure how. found stk module which works on 90+ volts.
have only 1 7293 so cant make stereo, found stk module , on sony powerboard from some component, cant make it work either its only oscilating... dont have enough time to order new parts
If you have a stash of random transformers, use one as a buck/booster transformer to lower the line voltage.
Bucking Xfmrs
Bucking Xfmrs
hm, interesting solution. but does bucking transformer has to be same primary wire diameter as transformer i am connecting it to? i sort of need to order some parts now so i will probably order 20 or so lt1083 and that is sort of easy solution to me as i have bigger heatsink stash than good transformers stash.
Not the primary, but the secondary needs to handle as much current as the main transformer's primary.
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