This circuit drives 4 sequences of 5 LEDs that can be of any color. The frequency depends on the characteristics of the photosensor. The circuit is from an 80's documentation.
Indicated by a Popular Electronics of the 90s originally to measure the light determining the exposure...
Other operational amplifiers series, such as the MC34072, MC34074, MC35071, MC35072, MC35074 d...
Found in American documentation, this circuit shows how to polarize a FET in bootstrap mode. The...