Battery powered magnetic pen having oscillator with improved efficiency and low power consumption

A battery powered magnetic pen comprising:

• a power source comprising battery for providing DC power to operate said pen, said battery having one terminal connected to ground;
• and an oscillator connected between a second terminal of said battery and said ground, said oscillator comprising
• a first transistor having a first base, a first collector, and a first emitter, said first emitter being connected directly to ground,
• a transformer having a primary winding connected in series between said battery and having said first collector, said transformer further having a secondary winding connected to said first base and forming a feedback loop from said collector through said transformer to said first collector, said feedback loop providing zero loop phase shift and a loop gain of one,
• capacitor means connected to said primary winding and said first emitter and having a capacitance related to the inductance of said primary winding to establish resonant conditions and cause said oscillator to oscillate,
• a second transistor having a second base, a second collector, and a second emitter, said second emitter being connected to ground,
• conductor means connected to said second base, said second collector, and said secondary winding for creating a common point of equal DC potential, and
• a resistor connected in series between said battery and said conductor means for providing a DC bias to said common point, said resistor having a resistance setting base-to-emitter voltages and amount of current flowing through said first and second collectors, of said first and second transistors.