Send the Pyramid power supply schematics to Repeater Builders TIP (RBTIP) ... and it can be available to EVERYONE.http://www.repeater-builder.com/rbtip/
Repeater Builders has over 28 thousand files occupying eleven gigabytes (11 GB) of server space.
All of it is FREELY downloadable information, and their servers transfer (i.e. downloads) over 80 Gb per month!
The current production power supplies by Pyramid Car Audio (NY) are available on their web site.
Power Supplies - Page 1http://www.pyramidcaraudio.com/items.asp?category=Power+Supplies+/+Inverters
Power Supplies - Page 2http://www.pyramidcaraudio.com/items.asp?category=Power+Supplies+%2F+Inverters&varpagenum=2
1. SELECT the MODEL you have (hyperlink on web pages above)
2. Manual for that Model will be highlighted on left side of product web page.
3. Click on link to Download the Manual.
4. Schematic is found on last page.
Pyramid Car Audio does not have schematics OR provide support/repairs for the earlier (legacy) DC power supplies
imported from Eastern Asia, when Pyramid was known by a different name corporate name (1970s/1980s).
HOWEVER, they use the SAME basic LM723 regulator and NPN pass transistor (2N3055, 2N3771) design that
Astron used for years -- SO repairs for the DIY radio amateur are to follow Astron tips at RBTIP.Pyramid's shortcomings with these legacy units are:
Using undersized heat sinks [they added fans to current design to address thermal issues];
lighter gauge steel for chassis; minimal uFd and VDC ratings for electrolytic capacitors; low cost unskilled labor --
which is apparent in their 1970s/1980s production units that I have repaired/rebuilt on the bench.
Some units do not have a crow-bar or over voltage protection circuit.
--- IF you have a broken unit, my suggestion is the same as Mike Holmes (HGTV) - RE
BUILD IT RIGHT ! ---
Repeater Builders - Linear Power Supplies 101 (educational)Astron is the example. Pyramid traditionally has been the low price / cut-corners offering.http://www.repeater-builder.com/astron/astron-intro-stuff.html