We found this circuit in a Linear Technology documentation from the 80's. It has a demodulator, being suitable for links and remote controls. Note the unusual type of detector configuration.
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...