| 摘要 |
<p>A deterrent device of the type which includes means for measuring light levels in the vicinity of the socket into which an adaptor can be plugged. The adaptor can receive a light bulb which is arranged to be illuminated when the light level is at a certain value. One aspect of the present invention makes use of a triac (102) which is connected in series with the light bulb. The gate of the triac (102) is controlled by a microprocessor (104) in such a way that the average current supplied to the gate is less than if the triac were driven continuously. Another feature is the use of the microprocessor (104) to switch the light bulb on and off at random.</p> |
