Back to Home   Schematics and
Service Information on
Astron™ Power Supplies

Compiled by Mike Morris WA6ILQ
Maintained by Robert Meister WA1MIK
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Contact information:
    Astron Corporation
    9 Autry
    Irvine, CA 92618 USA
    Voice: 949-458-7277
    8a-5p Pacific Time
    Fax: 949-458-0826
  Click here to visit 
the Astron Corporation web site
Click here or the logo above to go to Astron's web site

Note: there is an Astron Wireless Technologies company that manufactures some very nice antennas. It is a totally separate operation with no connections to the Astron Corporation that makes power supplies.

The contents of this page, like almost every page here at, are totally dependent on donations of information.
If you have a hint or a useful trick please consider writing it up and sending it in.

Please consider sending us a scan if you have an Astron schematic that we don't list below.
If you don't have access to a scanner we can scan a good clean copy.

We have received emailed requests for a schematic for the model BB-30M. Does anyone have one?

Astron makes both linear and switching power supplies, and some other products.
You should read this Astron Introductory Information article before any of the other articles here in the Astron section
It has some very useful information on the Astron linear and switching power supplies, with background, history, model-specific information, both repair and modification suggestions, photos, and more.

The Pyramid Gold Series linear power supplies are very similar in design and capacity to the Astron supplies. Both are based on the popular LM723 voltage regulator integrated circuit.

Reset Circuits:



Power Supply Model Information:

Please realize that you will find multiple different schematics listed below for the same supply as the designs changed over the years due to parts availability, circuit improvements, etc. For example, the early supplies use discrete stud-mounted diodes instead of half of a bridge rectifier (switching to an epoxy bridge module, despite the fact that only half is used, is one of the tricks that the designer at Astron used to lower the parts cost and manufacturing labor cost). You may have to download more than one schematic to get the one that matches your supply, and you may not find your schematic at all (as we only have the ones that were donated to us). If you have one that we don't, please consider sending us a scan or a Xerox copy.

When (or if) you find the schematic that matches your unit I suggest you print it and stuff a copy inside a plastic page protector, and tape it to the underside of the lid of the power supply cabinet! Several folks have mentioned in emails and on mailing lists that you can call Astron on the phone and you will hear them tell you that they don't have electronic copies of their drawings and they don't know how to email them. Trust me, the person that answers the phone will be amazed when you tell them that the drawings from different years for the same model power supply show some different component IDs and values. Unfortunately this is important because if one chooses to buy replacement parts (from Astron) they (according to Astron) need only supply the model and component IDs. Fortunately everything but the filter caps, transformer, and sheet metal are common Mouser or DigiKey parts, and I bet you could find the capacitors if you tried hard enough. Astron has to get them from somebody.

Notes about Model Numbers:

The model number is constructed from a prefix (letters), a peak current value (digits), and a suffix (letters). Look for a schematic based on the current value first. The circuitry is similar for the different prefixes and suffixes. For example, the Variable power supplies with front panel controls just add two pots. Any supply could have meters added, if they'll fit on the front panel. These don't affect the basic circuitry.



Astron builds supplies for several manufacturers - for example a Kenwood KPS-12 is based on the Astron RS-12, the Motorola RRDN6933A is an RM-35A-BB and the Motorola HPN9041 (45 kB PDF) is an RS-20 variant. Astron also builds custom supplies for GE, Icom, E.F. Johnson, Kenwood, Motorola, Uniden and Vertex. For example, the Astron SL-11RRA is a 13.8 Volt 11 Amp unit specifically designed with a metal sleeve built on top of the cabinet. The sleeve is sized so that a MaxTrac, Radius or GM300 mobile can slide into it; (click here for a photo).
A conversion list of Motorola to Astron model numbers can be found here.

Donations of additional schematics for the library below are always welcome !!
Send them to the maintainer listed at the top of this page (you will be credited unless you tell us not to).

See the "Notes" section above for an explanation of the prefix and suffix letters.

If you don't find the schematic for your Astron below, then we were not given it. If you find one somewhere else that we don't have, we'd appreciate a scan.

Astron model numbers indicate the peak (intermittent) current that can be drawn from the supply. The continuous current is somewhere between 50 and 80 percent of the peak current. For example, an SL15M is rated 14A peak but only 7A continuous, yet an RS20A is rated 20A peak but only 16A continuous. The absolute maximum current where foldback limiting occurs is usually 10 to 30 percent above the peak current rating.

The available output current on VS supplies depends on the output voltage. You get much less current at a lower voltage. For example, a VS50M supply is rated for 37A continuous at 13.8VDC but only 22A continuous at 10VDC and only 10A continuous at 5VDC output. The other VS supplies must be derated similarly. This has to do with the power dissipation capability of the heat sinks and transistors on the back and sides of the supply. At lower output voltages, there's more voltage across the transistors, so they get much hotter. Current foldback may also occur earlier at these lower voltage ratings, so beware. The Astron catalog has these derated current specs.

Important Note: Numbers in many of the schematics below, particularly the pin numbers on the 723 regulator IC, may be blurry. There is nothing connected to pin 8, so if you see something that looks like an "8" it's most likely a "6" where the top got closed up. The voltage charts on most of the schematics follow this scheme. Check some other schematics if you can't read the one for your particular supply as they're very similar.

Linear Power Supply Schematics:

Slim-Line (Low-Profile) Linear Power Supply Schematics:

28 Volt Linear Power Supply Schematics:

Switching Power Supply Schematics:

Switching Regulated Voltage Converter Schematics:

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This page originally created in August 2000 by Kevin Custer W3KKC
Totally rewritten and a number of schematics added on 10-14-2004 by Mike Morris WA6ILQ
Copyright © 2000 and and date of last update by

The following people contributed information to this web page (in alphabetical order by last name):
Greg Allison KZ6S (SK), Tom Allinson WB6DGN, Jim Bacher WB8VSU, Don Best N6ALD, Tim Bovard, Robert Burton KD4YDC, Henry Clark KC4KZT, W.C. Cloninger, Jr. K3OF, Steve Duncan, WA4ITA, Rick Eastwood W6RE (ex KB6LJO), Gary Eldridge KC8UD, George Franklin WØAV, George Henry KA3HSW, Larry Horlick VYHL, Jeff Kincaid W6JK, Ed Lambert K1ZOK, David Leeper K6DWL, Eric Lemmon WB6FLY, Doug Marston WB6JCD, Skipp May WV6F, Bob Meister WA1MIK, David Metz WAØAUQ, Brian Palmersheim KBØETC, Mike Perryman K5JMP, Richard Reese WA8DBW, Ron Rogers WW8RR, Robert Schulz KC6UDS, Bob Shields KA9TYL, JaMi Smith KK6CU (SK), Ron Vincent KF4D, and all those who chose not to be identified.

The Astron logo/image is a registered trademark and is used within this page with permission from the Astron Corporation.

The schematic images are copyright © Astron Corp. Each one is dated on the individual drawing. No copyright infringement is intended. If Astron had the schematic library on their web site we wouldn't need to.

This web page, the hand-coded HTML on it, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.