Re: Contact sensors?

[Joel Richards <jo@xxxxxxxxxx>]

I believe you can get rare earth magnets for around $1-$3 with free
shipping to the UK from dealextreme.com (the site looks dodgy but it's
fine really, I've used them a few times)

Also, hello all I'm new around here, nice to see a mailing list with
so much activity :)

- Joel


On 20 Nov 2008, at 08:15, Paul Gale wrote:

> Yes, that might work - I guess it's getting the right size of magnet
> and positioning in the right place.
>
> Where else can you get them from? I'm guessing the strength of field
> and hence distance varies with the physical size of the magnet?
>
> Thanks,
>
> Paul.
>
>
>
>> -----Original Message-----
>> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On
>> Behalf
>> Of Rob Iles
>> Sent: 20 November 2008 05:44
>> To: ukha_d@xxxxxxx
>> Subject: Re: [ukha_d] Contact sensors?
>>
>> Reed switch + rare earth magnets? I've got a couple salvaged from
an
>> old
>> HDD, and trust me - they're very strong! - can easily imagine them
>> closing a
>> reed switch at 50-70 mm!
>>
>> Apologies in advance if I've missed the point!
>>
>> R.
>>
>>
>> 2008/11/19 Paul Gale <groups2@xxxxxxx>
>>
>>>  Hi pete,
>>>
>>> Thanks but unfortunately the loft was finished some time ago,
so no
>>> chance of moving the cable. Not sure how successful it'd be at
the
>> top
>>> though anyway - may not be particularly sensitive? I know the
holes
>>> and fixings you're talking about.
>>>
>>> Any other ideas anyone?
>>>
>>> Paul. (Mobile)
>>>
>>>
>>> On 19 Nov 2008, at 14:45, "Pete Church"
>> <yahoo@xxxxxxx<yahoo%40petechurch.co.uk>>
>>> wrote:
>>>
>>>> Paul,
>>>>
>>>>
>>>>
>>>> If you haven't completely enclosed the Velux yet I would
suggest
>>>> putting a
>>>> sensor at the top of the window in the cavity above/behind
the
>>>> handle where
>>>> the motor sits (on an old style non Integra one). There is
also a
>>>> grommet/hole to pass the cable through the frame into that
cavity.
>>>> Because
>>>> of the way the mechanism works for cleaning there is still
>> clearance
>>>> at the
>>>> top of the window even with the window fully rotated.
>>>>
>>>>
>>>>
>>>> HTH
>>>>
>>>>
>>>>
>>>> Pete
>>>>
>>>>
>>>>
>>>> I have 3 large top opening velux windows in my loft and I
ran alarm
>>>> cable to the bottom of each. I want to fit a suitable
sensor to
>> detect
>>>> when the window is open. Trouble is, the way that the
window opens
>> for
>>>> cleaning (whole window swivels 180deg from the center-ish
of the
>>>> window) means that there's no clearance for positioning a
standard
>>>> magnetic contact sensor between frame and window.
>>>>
>>>> What I really need is a contact sensor that can operate
around 50-
>> 70mm
>>>> ish between the magnet and reed switch. I've not seen
anything like
>>>> this with that kind of operating gap.
>>>>
>>>> Anyone got any ideas or know of suitable sensors ?
>>>>
>>>> I guess there may be other sensor types that may be
suitable
>> although
>>>> of has to be fairly discreet (some kind of adjustable
proximity
>>>> sensor). Adjustable operating distance would be really
good as that
>>>> would allow fine-tuning.
>>>>
>>>> Thanks,
>>>>
>>>> Paul.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> [Non-text portions of this message have been removed]
>>>>
>>>>
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>>>>
>>>>
>>>>
>>>> __________ Information from ESET NOD32 Antivirus, version
of virus
>>>> signature database 3624 (20081119) __________
>>>>
>>>> The message was checked by ESET NOD32 Antivirus.
>>>>
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>>>
>>>
>>
>>
>>
>> --
>> Rob Iles
>>
>> RMIDevelopment
>>
>> Web: http://www.rob-iles.co.uk/rmidevelopment
>> Twitter: http://twitter.com/Rob_Iles
>> Skype: rob_iles
>> 12seconds: http://12seconds.tv/channel/rmi
>>
>>
>> [Non-text portions of this message have been removed]
>>
>>
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>>
>>
>>
>> __________ Information from ESET NOD32 Antivirus, version of virus
>> signature database 3626 (20081119) __________
>>
>> The message was checked by ESET NOD32 Antivirus.
>>
>> http://www.eset.com
>>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
> signature database 3626 (20081119) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
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>


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