Patent ID: 7586467
Filing Date: 2009-09-08
Classification: G09G

Abstract:
1. A load drive circuit using voltage-drive type semiconductor switching elements to supply high and low voltages to a load, said load drive circuit comprising: first and second semiconductor switching elements connected in series with a main power source; said load connected in parallel with said second semiconductor switching element; a switching command circuit that generates two pulse signals as switching commands to supply voltages to said load; a bistable circuit that is switched between two stable states in response to said two pulse signals and that holds a gate-emitter voltage of said first semiconductor switching element at either one of said high and low voltages; and a control circuit that responds to said two pulse signals to control said second semiconductor switching element to be turned on/off complementary with said first semiconductor switching element, wherein a power source to said bistable circuit is supplied from said main power source or another power source connected to a fixed potential point of said main power source, and a potential of a positive terminal of said source power to said bistable circuit is maintained higher than that of a positive terminal of said main power source.