Build Your Own Arcade Controls Forum
Main => Main Forum => Topic started by: Dudeman on November 25, 2008, 04:05:31 pm
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I need a bit of help here.
I need to build a circuit that will cut off to current flow when the 2 parts are not in line. I My first thought was a magnetic reed switch like in the drawing, but I want to make sure a reed switch can handle that load. I figure I'll be pumping 1A at 5VDC. The specs I've seen have "Switching Current" and "Contact Current" listed, but I'm not sure of the difference.
Does anyone know of a reed switch that can handle that, or any other ideas on how to accomplish this?
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Update:
Seems that "Contact Current" is the maximum allowable current the device can carry continuously.
"Switching Current" is the maximum current the device can handle during switching operations without damage.
So I guess the following specs:
Reed Switch
Pull-In Amp Turns Max:32
Pull-In Amp Turns Min:18
Circuitry:SPST-NO
Switching Current Max:1A
Switching Voltage Max:200VDC
Mounting Type:PCB
Body Length:15mm
Breakdown Voltage Min:325VDC
Contact Current Max:500mA RoHS Compliant: Yes
Mean this one won't work because I need 1A Contact Current.
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Transistor or a relay if you're dead set on using this particular switch.
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Nope... not married to that. It is just an example of what I am finding. Reed switches that have a contact current of .5A. So I'm looking for one that can handle 1A, or another way of designing this circuit.
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Most reed switches are fairly low current devices, you may find it easier to use a relay.
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Other options besides reed switches include inductive sensors and Hall Effect switches (digital). However, the former requires constant AC current, and the latter usually is more costly & lower current than reed and still requires magnet and a relay.
I think most BYO window/door sensors (http://www.home-technology-store.com/home-security/door-window.aspx) use reed switches.