Help with negative discrete regulator

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hello,

I've read with much interest those pages about discrete Zener regulators.

The schematic I'm interested in is the second one on this page


My problem is that I don't know how to make it functionnal for the negative supply :

- should I use the unregulated negative rail like the ground, and the ground as the positive rail ?

- should I "mirror" the circuit and use PNP insted of NPN (and vice-versa) ?




Thanks in advance !
 
Hi, often negative regulators perform less well.
The link shows that both PNP and NPN active devices at work, so it may be that a negative version will work just as well.

Back to your question:- the negative can be an inverted positive by swapping around the polarity of the components.
or
Build two positive regs. Connect one +ve output to the ground of the other. Call this connection your 0v common. The other two outputs are your +ve & -ve supplies.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.