This flasher for incandescent lamps was found in Radio Electronics magazine from July 1968. The frequency and duration of the pulses are adjusted in R1 and R3 depending also on C1.
This simple 555 biofeedback circuit was found in the December 1983 issue of Radio Electronics...
This circuit has a programmable alarm that can be triggered with different water levels. The...
Found in a 1991 Hobbyst Handbook, this circuit monitors both battery and alternator voltage. The set...