Found in a 1965 CQ magazine, this circuit uses period components. The unijunction transistor can be a 2N2646 and the relay has voltage according to the supply.
This circuit activates a relay when the conducting bars (probes) are held by a person. The circuit is...
This circuit in the National Semiconductor Fast IC Power Transistor manual uses a special power...
This wireless intercom has a range of about 300 meters using an integrated circuit that is not...