This circuit is from the 1983 Intersil Databook. The circuit has an A / D converter for display of 4 and a half digits being powered by a voltage of 9 V.
This circuit is suggested by Texas Instruments in his Optoelectronics Sourcebook. The transistors...
This timer, from an old American publication, uses indicator lamps, but can be modified to use...
Found in General Electric's documentation from 1970, this circuit is indicated for the so-called...