[time-nuts] Anybody want a Thunderbolt power supply?

Charles Steinmetz csteinmetz at yandex.com
Wed Aug 31 17:12:13 EDT 2016

jim wrote:

> with the venerable 2n3055 (1960s!) as the series pass device, and an
> exotic TIP29 (my 1985 databook has it, but the original datasheet says
> 1968) to drive it..
> They probably used the 1970s versions of the transistor, of course,
> since the 723 didn't come out til early 70s..

Fairchild introduced the orginal 723 (the µA723) in 1968.  I think 
National brought out the LM723 within the year, but can't swear to it.

While the schematic I posted shows a TIP29 driver transistor, that was 
for a different, 3A supply.  The lower-current +/-12v supplies in the 
HTAA-16W-A do without the driver, and connect the 3055 directly to the 
723 output (which can source up to 150mA).  The schematic I posted also 
shows foldback current limiting, which the +/-12v supplies in the 
HTAA-16W-A do not have.

Best regards,


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