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.
We find this circuit in a 1970 publication. Transistors can be replaced by current equivalents and LDR is...
This stage was used in old audio ampliiers and radios from the 1950s and 1960s. It uses one of the...
January 2017 - Texas Instruments' new TPS54200 integrated circuit for excitation of LEDs with a...