| 摘要 |
The switch includes an infra-red sensor 1, a filter amplifier 2, a direction discrimination circuit 3 connected to output of the filter discrimination circuit for dividing into two signals according to the signal phase and a processor 4 connected to output of the direction discrimination circuit and having a comparating circuit 41 and a driving circuit 43 connected to output of the comparating circuit, whereby when the total number of persons entering into a room is more than the total number of persons leaving the room, a controller 6 circuit will be actuated to supply power to a load RL1, RL2, eg lights, and vice versa. <IMAGE> |
