Re: Proximity Switches

From:         Simon Ellwood <>
Organization: Bodge It & Co. Ltd.
Date:         27 Jun 96 12:56:54 
References:   1
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>I understand that modern aircraft use a magnetic sensor called a proximity
>switch to determine the position of landing gear, doors, etc.  Does anyone
>know why this arrangement is used instead of a simple mechanical switch?
>Are the magnetic pick-offs more reliable than a simple switch?

My understanding here is that magnetic proximity switches have no moving
parts and so are much more reliable. As an example, many house burglar
alarms have similar devices fitted to doors, one contact in the door &
one in the frame. Opening the door moves the contacts away and "opens"
the switch.

Simon Ellwood.