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 is the basic operational amplifier configuration for gain 10. R2 can be changed to other...
This circuit was obtained in a 1988 publication, but it can be assembled very easily today, as all...
This circuit was found in a 1966 EEE. Transistors support modern equivalents and the waveforms are...