| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a safe and inexpensive brake controller for an elevator capable of preventing occurrence of secondary failure of a brake coil or a power supply device without increasing size of the brake coil and the power supply device when a current detector or an A/D converter causes failure and preventing possibility that a passenger is shut into the elevator. <P>SOLUTION: This brake controller is provided with a switching element 13 for a step-down chopper for controlling current of the brake coil 10 by a PWM 14, the current detector 15 for detecting current of the brake coil 10, the A/D converter 16 for converting output of the current detector into a digital signal, a current controller 18 for outputting a voltage corresponding to difference between output of the A/D converter and a command current value 17 to the PWM, and a switching device 21 for switching voltage output to the PWM from the current detector to a command value 22 of predetermined voltage when detecting abnormality of the current detector or the A/D converter. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
