This circuit is from Ferranti documentation from 1967. The operational is of the time, but the configuration is valid for modern equivalent components, including higher current capacity.
This circuit can be used as a source of signals for generators of different types, sirens, or...
This circuit is based on a 5 V LED flasher. We found it in October 1980 Radio Electronics...
This interesting circuit in which the LED display is circular imitating a common clock appeared in the...