We found this circuit in the magazine Eletcronics Now of July 1994. The power supply is according to the relay and the transistor can be any general purpose one.
This excellent circuit came out in a Japanese publication from 1971. It uses Japanese transistors of the...
This circuit is a little more elaborate with the previous one (CB19402E). The operational...
This circuit was found in a 1994 documentation, but it can be easily assembled today, as it uses...