DEC H7140 (11/44) power supply revisions and general advice?

tony duell ard at
Sun Oct 11 12:17:17 CDT 2015

> The bias voltage is generated by the chopper on page three in conjunction
> with T1 and some rectifying diodes on the motherboard. Then it is feed back
> to the bias board on J2:2 to produce the 5V. (page 2)


It's not totally obvious at first glance, but this is yet another SMPSU with the 
chopper on the Bias/Interface board. The transformer on the baseboard is
not a mains-frequency one.


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