Found in an Electronic Design and 1970s, this circuit uses transistors of the time. The transistors can be replaced with equivalents and the relay is 12 V depending on the power supply.
This circuit was found in a 1987 publication. A 4017 sequentially counts time in steps set by...
Found in 1967 General Electric documentation this circuit appears elsewhere in this section. SCRs are...
Found in an Electronic Design of 1964 this circuit has a control for the frequency and another for the...