Pulse-Generator & Signal-Tracer with BC547,BC557

Dual-purpose test-instrument Very simple circuitry, 1.5V Battery-operated Parts: R1__________________1M 1/4W Resistor R2,R4_______________2K7 1/4W Resistors R3________________150K 1/4W Resistor C1__________________2n2 630V Ceramic or Polyester Capacitor (See Notes) C2,C3_______________4n7 63V Ceramic or Polyester Capacitors D1_______________1N4148 75V 150mA Diode Q1________________BC547 45V 100mA NPN Transistor Continue reading