This circuit is intended for underwater communications. Of course, the critical point is the shielding to avoid water. The circuit is from an Electronic Hobbysts Handbook from the 90s.
This circuit, obtained in a 1983 magazine, can drive loads up to 100 mA if the transistors are...
It is possible to design a monostable multivibrator around a voltage comparator of the four...
This voltage inverter circuit is from a Radio Eklectronics from October 1965. It was used in...