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chapz

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  1. Thanks so much, you've been a GREAT help! ;)
  2. Hi audioguru, Thanks so much for your reply and advice! I will try it with 0.33 ohm as well as 0.22 and 0.47 ohm resistors and let you know what I find. One other thing; wouldn't it make more sense to use a power FET (n-channel) for the output pass transistors? That way we wouldn't need to use emitter resistors since the drain current actually decreases with increasing temperature. So something like two parallelised IRF640's? Your opinion would be much appreciated. :)
  3. Hi there, I've been reading through the posts, and have decided to build this power supply into my bench supply which I'm upgrading - the negative pumping scheme is more clever than my own design with a separate dual supply for the op amps! However, would just like to ask a question about the R47, 10W emitter resistors for the output pass transistors. I have a couple of R22, 5W resistors handy, and believe it would be fine to use them. Since the 2N3055 transistors are parallelised, the max current through each is 1.5A. We want a 0.2V drop across he resistors, so R will be 0.2/1.5=0.13. So R22 is about right. And power wise, P=(1.5)^2x0.22=0.495W. Am I missing something? Many thanks,
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