Door Window Sensor, I don’t know how ADT sense open or closed?

Thread Starter

killivolt

Joined Jan 10, 2010
780
I work for a company that uses a sensor wireless com at 345MHz signal to report back to the PLC Panel, Camera’s, Door Locks, Garage Door Controllers are Z-Wave around 908.2MHz and are POE.

They use a Battery CR2032 3vdc and they continually go out, we have a Takeover device that takes the wired sensors like ADT uses and transfers those connections to a module that will send a wireless com to our panel.

1. I need to know if there is a chip that will DC to DC convert I high voltage such as used on a solar battery, down to 3vdc for the sensor.

2. I need to know how ADT reports open or closed, is it wireless also or TTL design? Like Hall effect which would make sense.


Thanks in Advance,

kv
 
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Thread Starter

killivolt

Joined Jan 10, 2010
780
Most use a reed switch and send a coded response it it's a high or a low
These are Vivint sensors I’m a beta test house and trying to save money for customers, not in it for money. I’m not sure yet until I see the electronics, but they have a magnet, so my first bet is a resistive sensing circuit changed by Mag force.

I know there recessed door mag setup has a glass tube with a wire in it, my customer explained one the sensor we sent him had a broken glass tube so I’m still in the process of discovery.
kv
 

Thread Starter

killivolt

Joined Jan 10, 2010
780
Here's a look at one I've been playing with I'm using some parts off it.
View attachment 209198
We get some false positives, open when closed. If a reed switch is mechanical explains a lot. Eventually they would break over time I would think. A resistive circuit or Hall effect seems more the way to go rather than a mechanical. I’ll have to google some on their operation.

kv

Edit: Ok, then mechanical. Inert Gas prevents carbon break down, the glass tube holds it in preventing exposure to oxygen. Simplistic very functional I would suspect it would operate thousands of times unless there was a manufacturing defect, most likely would present itself early on vibration could create false positives, such as during a storm if a window or door might shake.
 
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Thread Starter

killivolt

Joined Jan 10, 2010
780
I just had the system installed I plan to monitor vibrational issues that might trigger a false alarm. Like how violently someone closes a window or not. Tactile sensors won’t or shouldn’t show false positives. But still unsure, I still lean to Hall effect if anyone says that isn’t the way to go let me know. More expensive possibly but seems more logical.

kv
 

be80be

Joined Jul 5, 2008
2,042
Vibration it take a lot of Vibration they close at a inch away and stay closed.
bigger the magnet the better they close.

And if the door or window has moved that much someone done broke in anyways LOL.

I don't think life will be a problem probably out live most people
I never seen a bad one just missing magnet, And the wired ones
would have wire cut but the reed was always still in good shape.
 
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Thread Starter

killivolt

Joined Jan 10, 2010
780
Got my Buck from china today, going to do a little cov19 cleaning with gloves.

kv

Edit: Decided to just let it sit in bowl then charge my 12v gel cell and print the new housing. I’ll mock a door window installation and test it over time, recording any events If any.
 

Alec_t

Joined Sep 17, 2013
11,291
The only problem I've ever had with a reed switch was the reed becoming permanently magnetised (by a moving magnet on rotating machinery....not a window :) ), thus keeping the switch 'on'.
 

Thread Starter

killivolt

Joined Jan 10, 2010
780
The only problem I've ever had with a reed switch was the reed becoming permanently magnetised (by a moving magnet on rotating machinery....not a window :) ), thus keeping the switch 'on'.
Never even thought about that, polarization. Now it makes me wonder if a hall effect or tactile sensor would be better than the reed switch. So, most of the time we have a false open, but that could be the last ”State” reported to the control panel before it went offline, or it literally stopped closing which would be opposite of the polarizing effect as you stated, permanently open, that would be weird.



kv
 
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