With the capacitor used, this circuit provides delays of 40 to 60 seconds. Larger capacitors can be used, and the SCR supports an equivalent. The circuit is from the 1977 RC semiconductor manual.
Suggested by a 90’s Radio Electronics, this circuit automatically activates the recording switch of an...
Found in a 1960s Electronic Design, this circuit provides a signal from the sensing of an analog...
Operating at a frequency of around 180 kHz, this transmitter was found in a Science & Electronics...