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.
It serves as a reference, since today we can have simpler and more compact solutions. This circuit is...
This circuit is from an old manual from National Semiconductor (Now Texas), using the LM2877 not...
This circuit is from the Motorola Linear Databook published in 1990. The circuit for 1 kHz can be...