This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common today. The circuit can be programmed for hourly intervals, according to the values of R4 and C2.
Found in an old Radio Electronics, this circuit uses common components today. The resistors of the IC...
Found in a 1965 General Electric circuit manual, this circuit uses SCRs from that time. Modern...
The modified Hartley oscillator, seen in figure 2, can generate signals ranging from 3 MHz to 10...