Suggested by Mullard in an old documentation, this circuit is based on a common phototransistor and on transistors that may be the modern BC548.
This four-phase stepper motor control uses a ST6982H IC. The maximum output current avaiable is...
This circuit was found in an Electronics World of 1968. The transistor can be any general purpose and...
For those who have multimeters that do not test transistors, in the figure we have a circuit that...