| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect an electric leakage surely and improve safety by a simple structure. <P>SOLUTION: A triangular wave component, which is a signal component with a frequency of 10 Hz and is output from an oscillator circuit 61, out of signals passing through a resistor 54 is detected by a band-pass filter 62 or a smoothing circuit 64. When the triangular wave component is detected, the output of a comparator circuit 65 is turned ON. When the triangular wave component is not detected, it is regarded that an electric leakage has occurred. A ripple component, which is a signal component with a frequency of 50 Hz/60 Hz, out of signals passing through the resistor 54 is detected by a band-pass filter 66 or a smoothing circuit 68. When the ripple component is detected, the output of a comparator circuit 69 is turned ON. When the ripple component is not detected, it is regarded that a break has occurred. <P>COPYRIGHT: (C)2010,JPO&INPIT |
