This circuit was obtained in an old Popular Electronics. It makes use of quite common components. The speed of the effect is set to R7. The circuit drives 20 LEDs.
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...