Inverter device with a circuit for generating pulse width modulation signals

An inverter device with a circuit for generating pulse width modulation signals, comprising,

• an inverter section including a rectifier for changing an alternating current to a direct current, a smoothing capacitor connected to a direct current side of the rectifier, and an inverter for changing the direct current smoothed by the smoothing capacitor to an alternating current with variable voltage and frequency by a control of pulse width modulation, and
• a circuit for generating pulse width modulation signal including;
• a counter for counting a signal and regulating a control cycle of a waveform of pulse width modulation,
• first register means for storing first information of the waveform of pulse width modulation,
• second register means for storing second information of the waveform of pulse width modulation, and
• a mode register for actuating one of first and second modes for automatically generating on-off timing of the waveform of pulse width modulation,
• wherein when the first mode is selected in the mode register, the mode register actuates the counter, output of the signal counted by the counter being compared with the information of the first and second register means so that an on-timing signal is outputted when the output of the counter coincides with the first information of the first register means and an off-timing signal is outputted when the output of the counter coincides with the second information of the second register means, and
• wherein when the second mode is selected in the mode register, the mode register actuates the counter within one cycle to automatically count down and count up again the signal after reaching a predetermined value so that an on-timing signal is outputted when the output of the counter at first coincides with the first information of the first register means and an off-timing signal is outputted when the output of the counter again coincides with the first information of the first register means after the signal reaches the predetermined value.