Found in an Australian documentation from 1991, this circuit was sold in a kit at the time. It is a small FM transmitter with a very common configuration, also found in other projects on this site.
This is the traditional application of the RCA CA1310 integrated circuit, obtained in a 1972...
This relay circuit with a dual channel MOSFET (not very common today) was found in an old American...
We present a DC-DC converter circuit that can operate with input voltages from 2.4 V to 14 V and...