Gary Pimm CCS as VR

Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

In Reply to: OK, on further thought... posted by ottoamps on October 9, 2005 at 14:59:44:

I've been using Gary's CCS as a voltage regulator for awhile now and have had very good results from it.
The primary issue is that for best results you should have at least 20mA flowing at all times. I finally figured out why this is so. The output impedance is determined by the inverse of the transconductance of Q1. The transconductance is STRONGLY effected by the current flowing through the MOSFET. At only a few mA the transconductance is so low the output impedance is too high. Above 20mA the transconductance starts getting pretty good so the output impedance drops significantly. Above 20ma it still gets better, but then you have to start worrying about power dissapation issues and heatsinking etc.

John S.

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

Follow Ups Full Thread

Topic - Gary's CCS VR Reg scheme as a reg - ottoamps 13:33:36 10/9/05 (2)

OK, on further thought... - ottoamps 14:59:44 10/9/05 (1)

Gary Pimm CCS as VR - John Swenson 10/10/0514:12:04 10/10/05 (0)

Follow Ups

Gary Pimm CCS as VR - John Swenson 10/10/0514:12:04 10/10/05 (0)

You can not post to an archived thread.