I'm building the bipolar version of the Zen regulated supply for an amp project. I have a question about Figure 6 from the Zen Variations 3 article: does the PNP Mosfet Q2 in that diagram have the source and drain connections reversed, or is it correct as printed? Figure 7 has the same layout. I'm scratching my head over this one, so any help would be appreciated.
The IRFP9240 (Q2) in Figure 6 is drawn upside-down. Ditto for Q2 & Q4 in Figure 7.
When hooked up correctly, the pass device would present its Source to the load (instead of its Drain), thus becoming a follower.
If you're going the bipolar route, you could always use the Zener stack to set the reference for a driver transistor--whether bipolar or MOSFET--and use that to drive non-Darlington pass devices...but the circuit would get more complex. Just depends on what you have on hand.
Grey
P.S.: MOSFETs are generally referred to as "N-channel" or "P-channel" instead of NPN or PNP like bipolars. The IRFP9240 is a P-ch device.
When hooked up correctly, the pass device would present its Source to the load (instead of its Drain), thus becoming a follower.
If you're going the bipolar route, you could always use the Zener stack to set the reference for a driver transistor--whether bipolar or MOSFET--and use that to drive non-Darlington pass devices...but the circuit would get more complex. Just depends on what you have on hand.
Grey
P.S.: MOSFETs are generally referred to as "N-channel" or "P-channel" instead of NPN or PNP like bipolars. The IRFP9240 is a P-ch device.
"avoidance of confusion." ???
"Both Drains have higher voltages than Sources" ???
I'm getting confused now... My figure 7 agrees with what Grey said... Q2 and Q4 are up-side-down... But then, -45V could be considered "higher" than -53V
Perspectives perspectives. As my Grandma used to say "to each his own".
"Both Drains have higher voltages than Sources" ???
I'm getting confused now... My figure 7 agrees with what Grey said... Q2 and Q4 are up-side-down... But then, -45V could be considered "higher" than -53V
Perspectives perspectives. As my Grandma used to say "to each his own".
A slightly different Zen 3 power supply question
Hello everyone,
My question is slightly different. I have been going to ask this for a while but didn't think it important enough to start a new thread!
Regarding the Zen 3 power supply, the statement is that at least the simplest version (Figure 1) is not suitable for Class AB or B amplifiers.
Is that true for the final versions, i.e. for Figures 2, 6 and 7?
If figure 6 and 7 are suitable for Class A and AB amplifiers, this would be a really simple and useful circuit!
What do you think Mr. Pass meant?
Regards,
George.
Hello everyone,
My question is slightly different. I have been going to ask this for a while but didn't think it important enough to start a new thread!
Regarding the Zen 3 power supply, the statement is that at least the simplest version (Figure 1) is not suitable for Class AB or B amplifiers.
Is that true for the final versions, i.e. for Figures 2, 6 and 7?
If figure 6 and 7 are suitable for Class A and AB amplifiers, this would be a really simple and useful circuit!
What do you think Mr. Pass meant?
Regards,
George.
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