| 摘要 |
A motion detector with at least one sensor to receive electromagnetic radiation, in particular in the infrared range, from a radiation receiver surrounding a monitored object at least partially, and with an evaluating circuit to trigger a control signal upon a change in the intensity of the radiation. A motion detector of this type may be manufactured cost effectively and is suitable for the reception of electromagnetic radiation from an angular range of up to 360 DEG of closed fields of sensitivity because the closed field or fields of sensitivity are formed by the shape of the sensor or sensors. In an embodiment of the invention that is particularly secure from interference, two sensors operating in a push-pull manner are provided, the fields of sensitivity of which are successive to each other in a path to the optical device, whereby the evaluating circuit emits a control signal only when within a predetermined period of time both a positive and a negative voltage pulse are present at the outlet of the radiation receiver. |
