Ed Williams wrote:

HI All,

I have been given a Pyramid PS-26K power sypply that is non-operational and
I am looking for a schematic for the unit. If anyone has one that they
could email me I would be very thankful. If you can assist please email me
at the below address.



73 de KN4KL ed

If it uses the common 723 type regulator, you should be able to
figure it out from the data sheet. National, (LM723) On-Semi, (MC1723)
and several other companies made the chip. If it is based on this part
you can find data sheets online with Google, or post the part number and
I can point you to the data sheet.
--


Michael A. Terrell
Central Florida

Ed Williams wrote:

HI All,

I have been given a Pyramid PS-26K power sypply that is non-operational
and
I am looking for a schematic for the unit. If anyone has one that they
could email me I would be very thankful. If you can assist please email
me
at the below address.



73 de KN4KL ed

As Mike Terrell has noted, most linear power supplies are based upon the
National LM 723 regulator IC. I would highly suggest that you read.

In my experience, I have avoided Pyramid supplies due to questionable
component quality
and some design issues (adequate heat sink for rating).
Check the bridge rectifier, pass trasnsitors and IC723 regulator.

Dave Metz's WA0AUQ 1996 SEITS article. It provides you all the basic
information
to troubleshoot or rebuild a damaged LM 723 based supply.
http://www.seits.org/features/pwrsup.htm

Schematic of Dave's design
http://www.seits.org/features/pwrsup.gif

Astron Power Supply schematics
http://www.repeater-builder.com/rbtip/astron-index.html

Good Luck

W9GB

Ed Williams wrote:

HI All,

I have been given a Pyramid PS-26K power sypply that is non-operational
and
I am looking for a schematic for the unit. If anyone has one that they
could email me I would be very thankful. If you can assist please email
me
at the below address.



73 de KN4KL ed

As Mike Terrell has noted, most linear power supplies are based upon the
National LM 723 regulator IC. I would highly suggest that you read.

In my experience, I have avoided Pyramid supplies due to questionable
component quality
and some design issues (adequate heat sink for rating).
Check the bridge rectifier, pass trasnsitors and IC723 regulator.

Dave Metz's WA0AUQ 1996 SEITS article. It provides you all the basic
information
to troubleshoot or rebuild a damaged LM 723 based supply.
http://www.seits.org/features/pwrsup.htm

Schematic of Dave's design
http://www.seits.org/features/pwrsup.gif

Astron Power Supply schematics
http://www.repeater-builder.com/rbtip/astron-index.html

Good Luck

W9GB