This 1968 Texas Instruments circuit uses diacs of the era. SCRs can be modern equivalents according to the controlled load.
This circuit can be implemented with other operational amplifiers. The formulas for calculating the...
This circuit is from a 1953 publication, consisting of an AM radio with 3 germanium transistors that,...
The sensor of this circuit is a common silicon diode and it directly drives a small cooler with a...