| 发明名称 |
APPARATUS FOR LOCKING OR UNLOCKING A DOOR THROUGH A REMOTE OPERATION BY OVERLAPPING A WEAK VHF SIGNAL AT AN AC220V POWER LINE, SPECIALLY CONCERNED WITH TRANSMITTING A WEAK VHF SIGNAL WHICH IS OVERLAPPED WITH AN AC60HZ SIGNAL BY MATCHING AN AC220 POWER LINE WITH A TRANSCEIVER THROUGH AN ANTENNA MATCHING CIRCUIT |
