| 摘要 |
PURPOSE:To obtin a safe protective operating function, by detecting an output voltage of switching elements through multiplex protection by crossing the position existing before and after the elements and obtaining the condition of discrimination of protective circuit operation. CONSTITUTION:If a switching element 3 is short-circuited, a detection circuit 5a detects the failure and if a switching element 3a is short-circuited, a detection circuit 5b detects the failure to inform the failure to a discrimination circuit 2b. The circuit 2b isues an alarm signal and actuates a protection circuit 1 through comparison and discrimination of the alarm signal with a signal from a turning- on/off indicating circuit 2a. Through the cross connection of the detection circuits 5a and 5b over the switching elements 3 and 3a, the protection circuit 1 can be operated even if the turning on signal is given and the detection circuit 5a or 5b detects no prescribed voltage, and even if a turning-off signal is given and the circuits 5a and 5b detect the power supply voltage, then the failure can never be overlocked to obtain a useful protection system. |
