Indicated for checking the operation of small FM transmitters, this circuit was found in an Australian publication from 1991. The components are all common nowadays.
This touch switch uses components that have easy-to-obtain current equivalents. The power supply...
After starting, this circuit turns off the relay in a time that depends on the 4020 pulse-count. This...
Connected to the output of a small amplifier or receiver, this circuit triggers a relay in the...