Schematic for a Tenma DC Power Supply 705-72

  • #1
I am searching for a legible schematic diagram for a Tenma 705-72 DC laboratory power supply. Each of its two channels uses a LM723 regulator and a pair of 2N3055 power transistors. One of the channels operates normally; the second channel puts out the maximum voltage (37 volts). Any help, particularly a schematic diagram, would be appreciated.
 

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  • #2
Averagesupernova
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I would start with data sheets for the LM723 regulators. There is only so far the power supply design can get away from what is recommended in application data.
 
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  • #3
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Adding to that, you have two almost identical channels to compare...
 
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  • #4
Tom.G
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  1. Inspect for burned parts; replace as needed.
  2. Replace both the LM723 and the 2N3055. (they are cheap)
If the 2N3055 failed, it likely took the LM723 with it.

Cheers,
Tom

EDIT: I found one 5 year old reference that said they contacted MCM Electronics for a schematic and they sent him one! MCM is now owned by http://www.newark.com, which sells the Tenma product line.
 
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dlgoff
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