We found this circuit in the October 1996 Electronics Now magazine. The circuit uses LDRs as sensors and drives relays. The relays must have voltages according to the power supply.
This different astable configuration was found in one in a 1974 Ferranti transistor manual....
Found in the December 1974 issue of Radio Electronics, this circuit is similar to the previous one,...
This circuit uses a pressure switch to turn a relay on or off. The supply must be 6 or 12 V...