| 摘要 |
PURPOSE:To prevent the generation of noise, by correcting the voltage of a single-phase power source by a square correcting circuit of a square aproximation correcting circuit and reading out the variation of this corrected voltage by the combination between a comparing circuit and a controlling circuit and performing the zero-cross switching to apply the voltage to a load by the controlling circuit. CONSTITUTION:A constant power controller is provided to a square correcting circuit 1 or a square approximation correcting circuit, and the voltage of a single-phase power source 2 is allowed to pass through a transformer 1a of the circuit 1 and is subjected to the half-wave rectification by a diode 1b and is applied to an operational amplifier 1c. The charateristics of a germanium diode 1d connected to the amplifier 1c are utilized to subjected the voltage to the square correction in the circuit 1. The output is smoothed in a smoothing circuit 3, and a voltage proportional to this smoothed input voltage and the output of a staircase wave generating circuit 5 are compared with each other in a comparing circuit 4, and the output is applied to a microprocess of a controlling circuit 6. A photocoupler 6b is controlled by the output of the circuit 6 to perform the zero-cross switching of the voltage of the power source 2, and the voltage is applied to a load 7, thus preventing the generation of noise. |
