| 摘要 |
PURPOSE:To prevent bad effect due to power system caused by high frequency component, so as to carry out stable power control by disconnecting load supply current with a frequency higher than a commercial ac power source frequency, and by making its on-duty rate variable. CONSTITUTION:When power source voltage is given to a multivibrator as well as a trigger circuit, charge current flows in capacitors C8, C9, and the voltage applied to a trigger device SBS is increased, and when the voltage exceeds breakover voltage, negative trigger voltage is applied to a transistor TRQ2. The TRQ2 is turned off, while the base voltage of TRQ4 is increased, and the charge current flows in a capacitor C1. A switching TRQ5 is turned OFF, and the negative current to a lamp L is cut. When the base electric potential of TRQ1 is turned negative due to the elevation of the charged voltage of the capacitor C1, TRQ1 is turned OFF, and TRQ3 is turned ON. TRQ5 is then turned On thereby, and load current flows in the lamp L through TRQ5. Load, current is thus controlled. |
