We found this circuit in the July 1994 Radio Electronics magazine. The circuit uses a general-purpose transistor, and the power supply can be up to 12 V depending on the relay.
We found this test circuit in a March 1967 Radio Electronics. The circuit uses a zener-regulated supply and...
This amplifier for small cassette tape players was found in an English documentation from 1969. The...
We found this circuit in a 2005 Linear Technology manual. The resistor is calculated for the...