Position: Index > Electrical Circuit >

TELEPHONE_LINE_IN_USE_INDICATOR

2014-11-20 01:21  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.


TELEPHONE_LINE_IN_USE_INDICATOR
When a telephone line is not in use, about 48 V appears across the line, which drops to about 10 V or less when the line is in use. This circuit switches a bicolor LED as an indicator.