Power factor compensating electroluminescent lamp DC/AC inverter

Claim 1

A power factor compensating DC/AC inverter circuit which comprises: (a) a source of direct electrical current having a positive terminal and a negative terminal; (b) a lamp operable on AC current; (c) a switching device having an input, an output, and a controller side, the device including a single transistor having a collector as an input, an emitter as an output, and a base as a controller side; (d) a transformer having a primary winding and a secondary winding, the primary winding being in series with the positive terminal of the source of direct electrical current and the input to the switching device, the output of the switching device being connected to the negative terminal of the source of direct electrical current, the secondary winding being in series with the lamp and in electrical communication with the source of direct electrical current, such that the secondary winding doubles as both an output and a feedback winding and the lamp doubles as both a load and limiting impedance for the controller side of the switching device; (e) a first diode having a cathode side connected to the end of the secondary winding opposite the lamp; (f) means for dimming the lamp, including: (I) a monostable multivibrator unit connected to the collector of the transistor of the switching device; (II) a variable resistor connected to the unit; (III) a dimming transistor having a base connected to the unit, an emitter connected to the base of the transistor of the switching device, and a collector connected to the cathode side of the first diode; and (IV) a resistor wired between the base of the transistor of the switching device and the negative terminal of the source of direct electrical current, to prevent undesireable leakage of current into the base of the transistor of the switching device.