1-minute delay (CB21408E)

This circuit with PUT is from a 1967 General Electric manual. The relay must have voltage according to the supply.

Battery Desulfator Charger (CB19386E)
This circuit, obtained from old documentation, allows the recovery of sulfated batteries. The...
5 V Power Supply (CB25403E)
This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The...
Headphone amplifier (CB7100E)
This high impedance headphone amplifier was found in American documentation from the 1990s. Any...