The circuit is from 1968, but we can use a modern one like the 741. The symmetrical power supply voltage (two batteries or source) can be from 9 to 12 V.
The figure shows how to implement an R-S flip-flop or bistable reset-Set with an LM3900...
This simple rising and falling siren was found in the October 1985 issue of Radio Electronics...
This circuit stabilized by quartz crystal was found in a European documentation (France) from the...