| 摘要 |
PURPOSE:To prevent electric power from being wasted by a method wherein the number of signals, which are output from an abnormal detecting circuit within a certain time period, is counted, a signal is output when the number of signals becomes two or more, and according to the signal, an inverter circuit is banned from generating oscillation for a certain time period and a lighting element on an indicator flickers. CONSTITUTION:A control circuit 13 is provided with an abnormal detecting circuit 20 which detects an abnormal action of an inverter circuit 8, an oscillation stopping circuit 21 which stops the inverter circuit generating oscillation according to the output signal from circuit 20, a start delay circuit 22 which postpones the re-start of oscillation for a certain time period after the oscillation is stopped, a counting circuit 23 which outputs a signal to a forbidding circuit 24 which bans the inverter circuit 8 from acting for a certain time period when the number of abnormal actions of the inverter circuit within a certain time period is two or more, and a driving circuit 25 which drives a switching transistor 19. As an alarm is issued only when abnormal action of the inverter circuit occurs twice or more in series, a meaningless alarm is prevented from being issued, and electric power is prevented from being wasted as heating is forcibly stopped for a certain time period. |
