| 摘要 |
PURPOSE:To prolong the life of the load, by forcedly maximizing the igniting phase to the switch for controlling phase when a commercial AC power is supplied to the load, and gradually returning to the igniting phase which corresponds to the output of a voltage value detecting means. CONSTITUTION:In a load electric power stabilizing device which supplies a stable electric power to a load lamp 12 by controlling the igniting phase of a switching element 13 in accordance with the variation of the voltage of a commercial AC power source 11, the voltage of the power source 11 is inputted into a supplied power voltage detecting circuit 15 through a transformer 14. The circuit 15 converts the inputted voltage into a DC voltage, and then, outputs a digital value Vs which is proportional to the voltage value of the power source 11 after A/D-converting the DC voltage. The circuit 15 controls the element 13 with an igniting pulse having a phase corresponding to the digital value Vs. In this case, a CR time constant and a transistor TR1 are installed in the analog input of an A/D converter of the circuit 15. The load is started to work when the electric power is supplied with a load electric power of the minimum level by turning on the transistor TR1 with a soft start signal SF and by igniting the element 13 with the maximum phase angle, and then, the rush electric current to the lamp 12 is reduced. Thus the element 13 is controlled by gradually returning the voltage to a normal supplied power voltage detected value. |
