| 摘要 |
PURPOSE:To completely prevent overheat, burnout of a driver, etc., by forcibly cutting OFF a drive signal if the number of times of outputs of a chopper signal exceeds a set number of times. CONSTITUTION:If a fire signal FS based on a drive data signal DD is output due to a runaway, etc., of a CPU 11 for a long time and a set time of a latch circuit 22 is erroneous, chopper signals CS are output in such a manner that the first signal CS1 remains as it is and second and following signals CSn are continuously output. Then, when a counter 41 counts the third chopper signal CS3, a carry signal C is output, and hence a protection signal G is output from the terminal Q of a flip-flop 42. Thus, gates 51 of signal cut-off means 50 are turned OFF to forcibly cut OFF a drive signal DRV. |
