EXPIRED
Actions: Add Comment
Tue 22 Nov 2011 - 12:26 am UTC
woollyisland
Customer
I am seeking a sample low voltage (5 V or below) proximity sensor switch. TTl level device (4.75V - 5.25V)
Small form factor, no bigger than 10mm in diameter. Can be capacitive or magnetic.
The device needs to sense at least a 5mm distance.
It is to be placed on a metal door, where it is desired to have no physical connection (i.e. a typical mechanical switch) to sense when it is closed. The choice of inductive proximity switch (vs capacitance) is so human hands do not send a false signal when placed over the switch. IR range detectors have been considered, but decided against as they cannot differentiate between human and door.
Such devices have been found in large quantities (must buy 960 of them at $2.50 each) so it is also desired that these devices can be purchased in small, sample size quantities.
Thank you
Tue 22 Nov 2011 - 12:46 am UTC
David Sarokin
Researcher
Can you give us a link to the large quantity devices you found? It would help us in searching for a source for sample size purchases.
David
Tue 22 Nov 2011 - 9:18 am UTC
Roger Browne
Researcher
Hi woollyisland,
Would your needs be met by a magnetically-operated switch? It closes a circuit like a relay, so it is usable at TTL voltages.
There's no physical contact when the door is closed. A small magnet, fixed to the door, comes within a few millimeters of the switch (which is fixed to the door frame) and closes or opens the circuit according to your needs.
Wed 23 Nov 2011 - 1:44 am UTC
woollyisland
Customer
Magnets are not an option because it is desired to have all sensing within one unit.
"Miniature Inductive Proximity Sensor" devices:
http://ramcosensors.com/pdf/Inductive%20Proximity%20Sensors/Miniature%20Inductive%20Sensors/8%20mm%20Miniature%205V.pdf
http://ramcosensors.com/pdf/Inductive%20Proximity%20Sensors/DC%20Inductive%20Sensors/Small%20Diameter%20Metal%20Barrel/8%20mm%20Threaded%205V.pdf
Thank you
Fri 25 Nov 2011 - 2:27 am UTC
woollyisland
Customer
Here is an example of an inductive sensor
http://www.kempstoncontrols.co.uk/NI5-K11K-AN5X-5-5M-SPLICED/turck-banner/sku/P313944
Fri 25 Nov 2011 - 2:56 am UTC
David Sarokin
Researcher
woolyisland...I'm a bit confused about what you need, as your question asks for a capacitive or magnetic switch, then seems to suggest you want an inductive switch, while your clarification says no magnets.
That said, there are plenty of sources specializing in sensors, such as ATM:
http://www.htm-sensors.com/prox/inductive.htm
Note that they offer small-footprint inductive as well as capacitive proximity sensors.
Let us know if any of these seem to meet your needs.
Mon 5 Dec 2011 - 11:33 am UTC
woollyisland
Customer
Thank you for the information. No luck. The challenge still remains for a small sensor (mini metal detector) to go on the door at the latch/doorknob side with a power consumption of less than 5V. The suggestions have been very much appreciated.
Mon 5 Dec 2011 - 1:09 pm UTC
myoarin
User
What about a light sensitive alarm?
http://www.kpsec.freeuk.com/projects/lalarm.htm
Tue 6 Dec 2011 - 7:50 pm UTC
bigjosh
User
Here is a prox sensor on Amazon for less than $8 delivered in unit quanities...
http://www.amazon.com/gp/product/B005HKXKOG/ref=as_li_ss_tl?ie=UTF8&tag=joshcom-20
It is speced to run at 6V DC, but will likely work fine with a 5V DC supply. The output is just a like relay so you can also connect it to 5V if you need to.
-josh
Fri 9 Dec 2011 - 1:55 am UTC
woollyisland
Customer
Thank you myoarin & bigjosh for your comments and efforts. We are getting closer. Bigjosh your Amazon link is interesting and in the right $$$ ballpark however it is 18mm in diameter. The upper limit of an acceptable diameter would be 10 - 11 mm.
Actions: Add Comment
Frequently Asked Questions | Terms & Conditions | Disclaimer | Privacy Policy | Contact Us | Spread the word!
© 2013 Uclue Ltd
Mon 28 Nov 2011 - 5:07 pm UTC
Comment
bigjosh
User
Is sensor surface mounted on door, or inside a mortise in the door?
You want to sense the door jam to know when the door is closed? Hinge side or latch side?
Is the jam metal too?
Have you seen this one?...
http://search.digikey.com/us/en/products/E2E-X1R5E1/Z1062-ND/407962
Available in single unit quantities and in stock.
-josh