This frequency divider by 10 uses discrete components only. Modern equivalent components can be used as the circuit is from an 80's documentation. Nearby frequencies can be used.
Found in an English documentation, this siren of good power is indicated for several applications, based on...
The circuit used is the 4093 configured as an inverter in this application from Radio Electronics from...
This circuit is from an Italian magazine Elettronica 2000 of September 1987. It is a pulsator for...