Monitor receiver (CIR21944E)

This receiver was found in a documentation by Gernsback from 1960. The circuit uses high impedance headphones and germanium transistors of the time.

Bistable Using Relay and SCR (CB541E)
This set-rest relay uses two SCR and two switches to control a DC relay. The circuit can be used...
Negative Line Current Monitor (CB5244E)
This circuit monitors the current in the negative line. The circuit is from a 2005 Linear...
10 Minute Timer (CB1501E )
The circuit shown in the figure was found in a 1974 publication. The field effect transistor may...