| 摘要 |
A phase control apparatus is provided with a first transistor 31, 31' whose source or emitter is connected to one end of an alternating current power supply 1 and whose drain or collector is connected to one end of a load 2, a second transistor 32, 32' whose source or emitter is connected to the other end of the alternating current power supply 1 and whose drain or collector is connected to the other end of the load 2, a diode bridge 71, 71' that rectifies an alternating current voltage of the alternating current power supply 1, and a parallel circuit of a zener diode 74, 74' and a capacitor 73, 73'. The parallel circuit generates a high potential relative to a potential at a negative output terminal of the diode bridge 71, or generates a low potential relative to a potential at a positive output terminal of the diode bridge 71'. A potential at a control terminal of the first transistor 31, 31' and a potential at a control terminal of the second transistor 32, 32' are switched between the high potential and the potential at the negative output terminal of the diode bridge 71, or between the low potential and the potential at the positive output terminal of the diode bridge 71'. |
