| 摘要 |
PROBLEM TO BE SOLVED: To drastically reduce the loss of energy by a method, wherein a Zener diode is connected in series with switching circuits connected to both sides of a capacitive load. SOLUTION: A connection point C of the cathode of a first diode 18 to an electroluminescent(EL) panel 19 is grounded via a first Zener diode 21 and a third switching transistor 22 as constant-voltage elements, which are connected in series. In addition, a connection point D of the cathode of a second diode 20 to the EL panel 19 is grounded, via a second Zener diode 23 and a fourth switching transistor 24. The cathode of the first Zener diode 21 and the cathode of the second Zener diode 23 are connected in the direction of the EL panel 19, and their threshold voltages are made higher than the supply voltage of a DC power supply. As a result, the loss of energy can be reduced, and the EL panel 19 can generate bright light over a long period. |
