This circuit with the ULN3784B appeared in the October 1984 issue of Radio Electronics magazine. It can typically be powered from 9 to 24 V.
This circuit was obtained from an American documentation from the 1980s. The T1 triggering...
Found in a 1974 Ferranti manual, this circuit uses diodes to limit the voltage on the transistors. The...
This circuit is from an English publication of 1991. With it you can use a common multimeter on...