PURPOSE: To improve lighting efficiency by providing a bypass channel, having a reverse current bypass diode for bypassing a zero cross switch mechanism, respectively in a pair of positive and negative switches of an inverter.
CONSTITUTION: When a positive trigger pulse from a plus pulse selecting circuit 2 is applied to a gate of a TRIAC T1 which is a zero cross switch, T1 in a plus side channel is turned on. When electroluminescence EL is charged to peak voltage, the T1 is turned off. Next, a reverse current is fed back to a plus current side through a reverse current bypass diode D1 of a bypass channel and collected as surplus power. When a trigger inverting pulse comes from a minus pulse select inverting circuit 3, a TRIAC T2 in a minus side channel is turned on and similarly actuated. In this way, EL lighting efficiency is improved.
SUGA TOSHIHIKO
KUROIWA AKIHIKO
NIPPON BEAM DENSHI KK