Scott75s1974
Well-Known Member
Thanks for the responses to these questions.
A question to improve my understanding of how these circuits work.
(I think my faulty imagination is to think of things in more TTL like signals which is what I played with as a kid. I'm trying to reimagine them as trusses from my statics class. Never had a circuits class alas.)
A question to improve my understanding of how these circuits work.
The measurement of -7mv at the collector of the PNP power transistor/pin 13 ... I was thinking this meant that that transistor wasn't getting biased. But I realize I'm not thinking of that being tied to the power resistors R20 and R21. I'm just imagining it as an independent output. So since it's tied through R20/21 to the collector of the NPN power transistor, it's being pulled negative. So am I correct to conclude that only the sum of that bias voltage matters, not either "half" measured to ground? Thus, I should not conclude that a negative voltage reading read against ground at pin 13 means the power transistor is not being biased?The value of -7mV at pin 13 is simply the DC offset of that amp + half of the 22mV drop you set for the bias, so -18mV + 11mV = -7mV
(I think my faulty imagination is to think of things in more TTL like signals which is what I played with as a kid. I'm trying to reimagine them as trusses from my statics class. Never had a circuits class alas.)
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