Testing of thermistors and SCRs (CB21391E)

This circuit was found in an old American manual. It is intended for testing SCRs and thermistors using indicator lamps.

Commercial Radio TR 62 (CB18370E)
This commercial medium and short-wave radio was manufactured in Japan in the 60s. The circuit has...
Bar or Moving Point LM3914 (CB17538E)
In the figure we have the way to use the LM3914 as a scale of bar LEDs or moving point. The...
Touch Bistable (CB15005E)
Alternating taps on the pressure switch or sensor, cause the output to alternate the high and low...