This circuit generates frequencies determined by R3 and C1. We found it in the Radio Electronics magazine of May 1988. The power supply must be symmetrical.
This egg timer has been found in an English magazine that no longer exists in 1982. The...
This circuito from the 1977 GE Semiconductor Manual circuit provides timings from 0 to 90 seconds...
This crystal-controlled circuit was obtained from a 1980s documentation. The power supply should be 5...