Three-phase converter (CB21931E)

This circuit was found in the RCA Power Transistor manual from the 70's. The circuit uses power transistors of the time.

Temperature Control (CB6003E)
This circuit functions as a thermostat triggering a relay when the boil control temperature...
Latching relay (CB25722E)
The figure shows how to connect a relay to obtain the latch effect. The circuit is from an...
Extension Bell (CB15685E)
With this circuit it is possible to use a DC buzzer (not a transducer) as an extension of the...