This circuit was found in a1980s Motorola documentation. The integrated circuit is from that time. The frequency depends on the crystal.
This circuit is connected between the phone output of a cassette recorder and the input of a...
The time obtained in this circuit, from a 1978 publication, depends on R3 and C. R3 can have...
September 2016 - can already be purchased at Mouser Electronics the Robot Scribbler S3 from...