This 1965 circuit uses a Philips 4068 tube to measure extremely small charges. The circuit has as indicator a micro ammeter and the transistors are of the time.
This circuit uses a 7-segment display to indicate the logic level of a test circuit. The power...
This is the conventional application of the UCN4202 to control a 12 V stepper motor with current...
Small variations in the resistance of the subject's skin holding the test leads are detected by...