(Hopefully) simple reed switch question

[xxJaRxx]

Hi guys,

I am looking at using a reed switch for a project I am working on at the moment and I have a couple of questions..

I will be using the reed switch as a simple indicator as to whether an object has moved or not. The idea is that the switch itself will be mounted to an object that doesn't move and connected to a microcontroller, the magnet will be mounted to the object that does move, when the object moves away, the reed switch 'trips' and the microcontroller sounds a buzzer.

The reed switch I am looking at is this one:
http://www.rapidonline.com/Electronic-Components/Brass-proximity-switch-62088

My main question is regarding the 'Switching distance: 10mm min'. What exactly does this mean, the magnet has to be within 10mm to close the contacts or more than 10mm?!

Also is there anything else I need to know about reed switches? I haven't worked with them before.

Cheers for any advice
James

 

[davenn]

hi there

has to be within 10 mm to close the contacts

cheers
Dave

 

[xxJaRxx]

Cheers Dave! Is that a fairly normal switching distance for a cheap-ish reed switch and magnet? It seems to be very short.

Can I use any magnet to close the contacts of a reed switch? E.g. could I go out and buy a really strong magnet and use it to increase the switching distance without any issues?

Cheers
James

 

[davenn]

yes thats a typical distance
a stronger magnet magnet may give you a few more mm