This circuit provides a delay for the activation of an alarm, giving the owner time to leave the premises. The circuit is from the 1995 Encyclopedia of Electronic Circuits Volume 5.
This Colpitts oscillator with JFET has the amplitude of the signals stabilized by a diode. The...
This circuit is from European 90s documentation. The integrated circuit used is not very common...
This circuit of an old publication makes use of SCRs that admit modern equivalents. The frequency...