A simplified electronic ballast for a discharge lamp which provides dimming
by control of inverter frequency through modulation of magnetizing current
in a transformer such that the switching frequency is made substantially
independent of the load presented. The principle of frequency control in a
manner independent of the load is extendable to other types of loads and
power supplies and converters to regulate power coupled to the load.
Clamping capacitors are used to replace other clamping circuits in order
to allow current injection to be controlled by a simple variable voltage
while frequency control by current injection provides enhanced circuit
performance.
