This automatic brightness control that uses an LDR as a sensor, was found in American documentation from the 1980s. Resistors in series with LEDs depend on the desired current.
This experimental TTL circuit is from 1992 documentation. It produces programmed sounds set in the...
This circuit is from a 1968 Electronic Design. The characteristics of the output transformer are not...
In the figure we have a circuit that fires from a positive pulse of short duration applied to its...