Deadbolt indicator

Hi All,

I'm very much a beginner in the electronics area, but I've been playing around with resistors, led's and batteries - so I understand those basics.

Now I want to apply what I've learned!

I want to make a indicator LED light when the deadbolt to my door is locked. I've made a (ugly) graphic to show what I'm thinking.

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The basic idea is that the deadbolt closes the circuit. What I don't know is how to create and attach the connectors to the door jam. Is there any circuit pieces like this i could start from? What do i need to do to make it safe? Do I need to attach a small plate to the end of the deadbolt to properly close the loop?

Thanks for any help!

Reply to
David Humpherys
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You would be better off not to let the dead bolt make the connection. The bolt could push a micro-switch or activate something else that would close a circuit.

Tom

Reply to
Tom Biasi

Thanks Tom, Do you have any recommendations for a micro-switch that would work for this type of thing?

Reply to
David Humpherys

You don't really need a switch. You could re-arrange the two pieces of metal stripes like this:

| Bent stripe | \ +------- / \ | | |

Reply to
Mr. Man-wai Chang

Look for one with some travel play in the activating, this way you can make contact and still have room to push some more and not damage the switch. Tom

Reply to
Tom Biasi

That would probably work better than asking the deadbolt itself to make the connection. But what you're doing is making a switch, and probably a pretty poor one.

If you can find a switch that'll fit, that's better.

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Tim Wescott 
Wescott Design Services 
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Reply to
Tim Wescott

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Finding a way to mount the switch is going to be a challenge -- you want to have a lot of leeway for where the deadbolt ends up, while still reliably actuating the switch. So an arrangement that either lets the switch be actuated by the side of the deadbolt as it enters its pocket, or that has a long spring on the switch, is probably best.

Mess with it. These electromechanical projects always end up being more mechanical than electrical in the end.

--
Tim Wescott 
Wescott Design Services 
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Reply to
Tim Wescott

A magnet glued to the end of the deadbolt, and a Hall sensor in the door jamb would get my vote.

Cheers

Phil Hobbs

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Dr Philip C D Hobbs 
Principal Consultant 
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Reply to
Phil Hobbs

I get what your saying. Thank you for the mention. Any idea where I would get this type of material ? And how would I attach it to the wood without saftey problems?

Totally understand it might not be as good as a production switch.

Reply to
David Humpherys

Thanks for the links Tim. you're right - i need to pull the door trim off and see what sort of space i have to deal with, then figure out what the area of impact would be.

is there some technical jargon that notates at what point the stitch turns on? In other words, when the bolt connects to the switch and starts pushing, how far does a switch have to push to actually close the loop. Is there a word for that?

Thanks for the help!

Reply to
David Humpherys

Thanks Phil - a totally different solution i didn't know existed. and a cheap one at that.

I'd have to find a thin magnet so that it didn't interfere with the door opening-closing. something like this might work.

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thanks for all the help everyone!!!

Reply to
David Humpherys

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I'd elect for a reed switch instead of a Hall sensor, which would be 
much less expensive and, while the deadbolt was open, require zero 
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Reply to
John Fields

Agree, if he going the magnet route. Which I think is a viable solution. Rat Shack has magnet/switch pairs pretty cheap.

Tom

Reply to
Tom Biasi

That's true, but (a) it's a lot less sensitive, so it would have to be right up against the magnet, and (b) it's made of glass, so it would be vulnerable to breakage if somebody slammed the door, or was working on the hinges, or....

Besides, the OP sounds like he wants to learn some electronics.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
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Reply to
Phil Hobbs

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I have an electronic combination lock which, if it's flashing, 
indicates that the door to my lab is unlocked, even if it's closed. 
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Reply to
John Fields

How about two springs, parallel. The deadbolt pushes up against both of them. The springs could be inside drilled holes in the door frame.

_______________________

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Reply to
John Larkin

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Nope. 

Neodymium Boron Iron magnets are insanely strong, and reed switches 
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Reply to
John Fields

That's exactly what I thought, but what if they droop and touch each other? ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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Reply to
Jim Thompson

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Don't you mean series?
Reply to
John Fields

A source for cheap, small, thin,powerful magnets is that broken set of earbuds that everyone seems to collect these days. Also, I run across two types of hall effect switches. One type stays on until the magnetic field is reversed, the other stays on only while the magnetic field is present. Eric

Reply to
etpm

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