[Convert 0-30V 3A PSU to 5A or more]

Hi Audioguru!

First off all: thanks for your fast reply. I didn't want to be impolite but I messed up my thread above because I didn't know how to quote properly. I hope it will be better next time!

So long
Benno

[Convert 0-30V 3A PSU to 5A or more]

typing error:I meant Rl at the output.


Where do you know this from? Designers determination?


But without R15 there would be no current-limiting, when the load is discharged through D10 and Q1?

- Does C5 shorten high-frequency disturbances of the mains?

- Q2 is a emitter-follower, correct? Is this the reason why R16 is needed? And why emitter-follower instead of a common emitter configuration?

- The 3 parallel output-resistors: Why do they have resistors at their emitters?


I know, had to wait to ask my questions.

Bye
Benno

[Convert 0-30V 3A PSU to 5A or more]

Hi everybody!

Audioguru, your're doing an excellent job! Thank you very, very much for your commitment!
I'd also like to built this PSU and understand how it works. As far as I can see there were lots
of changes by the component values but the circuit's topology stayed the same except the
additional resistor Rl. I've read the function description, but I still don't understand half
of this circuit I think.Now here are my questions:

1.This additional resistor Rl forms a load that is needed for correct function of the regulation even if no external load is connected?

2.What is R1 good for? Why is the smoothening-capacitor C1 not enough?

3.Why 15W for R7? With P=R*I^2 and a max. current of 5 amps follows a max. dissipation of 6,75W. Is this because a 15W resistor doesnt get as hot as a 9W resistor? Does this resistor need an extra heat-sink? The lower the value of R7 the better, because less power is dissipated in R7?

4.U1 provides a constant voltage which is amplified by U2. The output voltage is fed back to U2 by R12 (C6 is for stability?). C9 is for stability, but what are R15 (base-resistor for R13?)
and D10 good for?

5. I don't know what D11 and C7 are doing. Same with D10

I hope somebody (I think it will be audioguru ;-)) can help.

Bye
Benno