Circuit

Product Description
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Here is the schematic diagram for a 20 Watt driver. I developed this circuit in 1985, and used it to build a lamp that found much use both as camping light and as emergency light during the then-frequent power outages.
The two transistors work as a push-pull oscillator. To avoid crossover conduction, during operation the bases [...]

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
Q2________________BC557 45V 100mA PNP Transistor
SW1________________SPST miniature Slider Switch (See Notes)
J1_________________Stereo [...]