| 摘要 |
PURPOSE:To obtain a device having a simple constitution of circuit with a small loss of energy and high accuracy of stabilization, by providing a charging circuit having a series connection a capacitor and a transistor and controlling the voltage of a DC output circuit with the charging voltage of the charging circuit. CONSTITUTION:A capacitor charging circuit having a series connection of a rectifier D1, a capacitor C1 and a transistor TR1 is provided to a commercial power supply or an output circuit of a transformer. Then the voltage E2 of a DC output circuit which is controlled by the charging voltage E1 between both terminals of the capacitor C1 is compared with the preset desired output voltage as well as with a certain level of reference voltage of the DC output circuit. Based on the result of this comparison, the on/off time limit is controlled for the TR1 to control the charging time limit to the C1. For instance, a circuit shown in the diagram is used to control the TR1 via a photocoupler PC, a TR3, a TR2, etc. and in accordance with the result of the above-mentioned comparison. |
