| 摘要 |
<p>A power supply for generating of a mainly sinusoidal output voltage, the magnitude and frequency of which are adapted for driving of mains operated apparatuses, comprises means (10) for generating a DC voltage, a DC/AC converter (18) including controlled semiconductor switches (19, 20, 21, 22) and an electric control device (30) for emitting to the semiconductor switches suitable commutating signals according to a predetermined program to keep said switches closed and open, respectively, such that the desired waveform for the output voltage be achieved. Means (R) are provided for sensing of a paramater associated with the load current of the power supply, said means cooperating with the control device (30) such that upon the load current exceeding a predetermined value the commutating signals are cancelled but are reconnected after a period of time which is considerably less than half the period of the output voltage. The control device (30) emits commutating signals continuously with breaks determined by the load current exceeding said predetermined value.</p> |
