Settings like to this can be found elsewhere in this section. This was found in an American documentation from the 70s. The integrated parts used are from that time.
This circuit is from a Popular Electronics from the 90s. The circuit has a tone frequency...
This solar powered circuit was found in a 1991 documentation. The transistor is a general purpose...
This circuit is based on a common cathode 7-segment display. The circuit is based on CMOS...