| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electronic transformer which can restart a power supply to a load without reclosing an ac power supply when it becomes a normal load after operating by an unloaded condition. <P>SOLUTION: The electronic transformer 1 includes a resetting means 4 which reduces the connecting point potential of a resistor R1 for a trigger and a capacitor C3 for a trigger at the zero crossing point of the output voltage of the ac power supply AC. The current flowing to a trigger element Q3 at the zero crossing point of the output voltage of the ac power supply AC is reduced smaller than a holding current which holds the trigger element Q3 in a conductive state. Even after operated by the unloaded condition, since the trigger element Q3 is once turned off at the zero crossing point of the output voltage of the ac power supply AC and again conducted, the switching element Q2 is turned on at the timing for conducting the trigger element Q3, and the oscillation of the inverter circuit 2 is started. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
