A method for controlling power to an electrical load using dual pulse width modulation
(PWM) to minimize in-rush current to the electrical load, such as a heater element.
An output from a power source, supplying an alternating current, is modulated by
a first PWM control signal to provide a first modulated power level to the electrical
load. The first modulated power level is modulated by a second PWM control signal
to control power supplied to the electrical load at the first modulated power level.
The first PWM control signal operates to control the number of half cycles of current
in order to provide one-third, two-thirds or full cycle power. The second PWM control
signal operates to define a duty cycle and period for providing the power defined
by the first PWM control signal to the electrical load.
