| 摘要 |
Monitoring unit comprising a switching member arranged so as to switch off and switch on electric current to electrical equipment, which monitoring unit comprises what is known as an infradetector 4 arranged so as to detect movement of a person by virtue of the inclusion of a control circuit 5, to which the infradetector 4 is connected, which control circuit is arranged so as to transmit a control signal to said switching member 1 depending on signals from the infradetector 4, which signals indicate the presence or absence of a person and which control circuit 5 is arranged so as to transmit a control signal to the switch 1 in such a manner that the equipment 6 receives electric current only when the infradetector 4 indicates the presence of a person, the control circuit 5 being arranged so as to maintain the current supply only on condition that the infradetector 4 transmits signals indicating presence, which signals are at the longest interrupted for one or more periods of time of which the duration is shorter than said predetermined time. The invention is characterized in that the control circuit 5, on indication of presence after a period of absence of a person, is arranged so as, by means of a current-sensing member 7, to sense whether current is being conducted directly through the household equipment 2 and arranged so as, if this is the case, to switch off directly the current supply to the household equipment 2. According to a preferred embodiment, the control circuit 5 comprises a time delay circuit 6 which is arranged so as to delay the transmission by the control circuit 5 of said control signal for a predetermined time. <IMAGE> |
