This circuit for light modulated in frequency (FM) was found in documentation of the 90s. SUS is uncommon today, but transistors admit 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...