This circuit was obtained from an American documentation from 1976. The circuit has a dynamic range of 100 kHz. FETs may be replaced by current equivalents.
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...