This circuit uses a crystal phone and can be built with more modern transistors like the BC548. The original circuit is from a 1979 publication and is powered with only two AA or AAA batteries.
We found this circuit in a 1988 documentation, but the components used are still current. The...
This simple timer uses one of the six inverter ports on a CMOS integrated circuit. Rx and Cx...
With an output power of 1.5 W under a 12 V supply, this circuit makes use of transistors that are...