Capacitive Relay (T1527E)

Found in Popular Electronics from August 1956 this sensitive two-tube relay is powered directly from the mains power supply.

Phase Shift Oscillator (CB14952E)
This traditional circuit generates a 200 Hz sinusoidal signal. The frequency depends on the...
Active rectifier (CB7065E)
This circuit supplies a continuous voltage at its output, which is the peak value of the...
CB15908E Photodiode Amplifier (CB15908E)
This circuit is suggested by National Semiconductor and has an excellent gain, for a photodiode as a...