±15V Fixed Power Supply
For my Extron Composite Video 8x8 Matrix Switcher in my Home A/V System

Devin R. Ott
Designed & Constructed – August 2013


Utilizes two ungrounded +18V @ 2.75A switching power supplies (salvaged from my company’s warehouse) as input voltage sources, referenced above and below earth ground to feed the positive and negative linear regulators.


This is a very standard circuit I designed, tested, assembled, and installed in a single weekend to restore operation to the 8x8 composite video matrix switcher I integrated into my centralized apartment A/V system.  This unit handles video switching for all DVD players/recorders, security camera feeds, low-res cable tuner feeds (for touch panel preview), and play station in my apartment.


http://www.extron.com/product/img-lg/mavplus88v_60-658EZ.jpg    PowerSupply_8x8_VIDEO_Matrix_pic6_L



Click HERE for complete design notes [PDF]

Final Assembly:

PowerSupply_8x8_VIDEO_Matrix_pic2_L    PowerSupply_8x8_VIDEO_Matrix_pic1_L

Dual +18V, 2.75A ungrounded switching DC power supplies provide the 18V input (referenced above & below chassis ground) to the
linear IC voltage regulators.  Also provide non-conducting mounting surface for the ±15V power supply assembly.


Final Installation:

Red LEDs provide convenient at-a-glance verification of output voltage from linear regulators.

PowerSupply_8x8_VIDEO_Matrix_pic4_L    PowerSupply_8x8_VIDEO_Matrix_pic5_L    PowerSupply_8x8_VIDEO_Matrix_pic6_L

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© 2014, Devin R. Ott