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Magnetic switch for widnow open
Posted: Sat Aug 28, 2004 6:32 pm
by lanceh5
I want to be able to tell when a window or door is open or closed in a house. I looked at Radio Shack magnetic switches that were 1/4 inch diameter but the magnet would open the switch about an inch away. I have 27 aluminum horizontal sliding widows and 7 doors. <p>I plan to make an led board indicating if a door or window is open in this two story house. It there an easier way than using magnetic switches to light a led board?
Re: Magnetic switch for widnow open
Posted: Sat Aug 28, 2004 7:49 pm
by Chris Smith
You want it more accurate?<p>Off set them half way to begin with. <p>Lower one by 1/2 inch on installation. [or more]
Re: Magnetic switch for widnow open
Posted: Sat Aug 28, 2004 10:01 pm
by pberry
Having the magnetic switches detect from a distance is advantageous because you can then leave the window slightly open for ventillation and still have the alarm active. They make switches especially for this.<p>You could break the 34 security points into zones and that would reduce the number of LEDs and the amount of wiring (which is the most difficult part). To group everything in a single room room (3 windows and a door for instance) into a single point is usually adequate.<p>There are also battery powered wireless security devices, so you don't have to cable at all.<p>I think there are also some X-10 type devices that use the existing 120 VAC power wiring for the communication line.<p>It's all a balance between cost and effort.
Re: Magnetic switch for widnow open
Posted: Sat Aug 28, 2004 10:04 pm
by bodgy
Have you thought about using LEDS and opto couplers or very small reed switches or microswitches, all of these could be easily 'hammered'
into window frames.<p>
Colin
Re: Magnetic switch for widnow open
Posted: Sun Aug 29, 2004 6:16 pm
by lanceh5
One of the problems installing the switches is that I need to install them now before the drywall is placed. The drywall will be 5/8 inch. One solution is to drill a 1' dia hole about 2" deep and place the switch in the hole then after the drywall is installed drill a hole and pull the switch out enough so that it will work. The magnets will need to be epoxied to the sliding window if it is a solid piece. I have seen circular magnets that have a hole in the center. <p>Here is a web site that sells the type of switch I am conserving. <p>
http://www.allelectronics.com/cgi-bin/c ... type=store