| 摘要 |
PURPOSE:To provided the subject unit wherein a switch is automatically changed over from the half-wave rectification at the time of high tension to the voltage doubling rectification at the time of low tension, whereby even when the unit is connected to any source, the device can be operated in the normal operation. CONSTITUTION:The unit is provided with a voltage detection circuit 7 which detects the voltage value of an AC source 1 and generates a signal in response to the detected value. The unit discriminates the intensity of the voltage to open and close a switching element consisting of triack SD and thyristor CRI. With respect to the connection to the high tension AC source, the switching element is opened to carry out half-wave rectification, whereas with respect to the connection to the low tension rectification, the switching element is closed to carry out voltage doubling rectification For this reason, even when a source plug is inserted into any of, for example, 100 V and 240 V sources, half-wave rectification and voltage doubling rectification are automatically changed, and hence a DC power source unit capable of normally operating can be obtained without destroying the load and parts within the unit. |
