On 2017/08/14 1:39 AM, Geo wrote:
On Sun, 13 Aug 2017 19:15:52 +0000 (UTC), bob prohaska
wrote:


Sorry, it's a reliance electric 701819-X . Web searches find it for sale,
but I haven't found anything like a spec sheet. It's described as a
rectifier, but with six leads it's likely to be more than just that.

It is a full bridge rectifier but two arms of the bridge use SCRs
instead of diodes. Their gates are controlled (via the G1 and G2
terminals) to switch on for a variable portion of a cycle thus varying
the power transferred.
A Solartron variable bench power supply of that vintage used the
technique to reduce the input to the linear regulator when then output
voltage was dialled low and the 5 Amps would have resulted in too high
a dissipation in the regulator transistors.



An early 70s (?) local Canadian electronics catalogue (R.A.E. Industrial
Electronics) has some of these SCR/Bridge rectifiers listed on pg. 138 -
made by IR. See if you can find anything on the PACE/paks design. Happy
to email the two pages showing the IR versions...these devices with 6
terminals have up to six different internal configurations.

1-Single Phase hybrid bridge with common cathode connection
2-Single Phase hybrid bridge with common anode connection
3-Single Phase, all SCR, controlled bridge (8 terminals)
4-Single Phase hybrid bridge with doubler connection
5-Single Phase, all SCR, AC Switch. (anti-parallel controller) (4 or 6
terminals)
6-Single Phase, hybrid AC Switch. (anti-parallel connector) (5 terminals)

John :-#)#