The present invention relates to a pulse width modulation control system
which is capable of preventing arm short phenomenon and controlling a
operation circuit precisely by securing dead time. The present invention
comprises a counter which sets initial voltage value differently and
outputs chopping wave crossed at its maximum voltage value and minimum
voltage value, an adder/subtracter which adds/subtracts signal generated
by the counter, a reference voltage value generation unit which is
inputted signal outputted from the adder/subtracter and outputs two
different reference voltage values to single chopping wave, a comparator
which compares reference voltage value generated by the reference voltage
value generation unit with voltage value outputted from the
adder/subtracter, and an output control unit which outputs PWM (Pulse
Width Modulation) positive signal (S.sub.PWM+) or PWM (Pulse Width
Modulation) negative signal (S.sub.PWM-) in accordance with the output
voltage value of the comparator.
