12V Shotgun Lock, with Keypad and Battery Backup in House?

rdiggidy

Here is the setup:




I have my shotgun mounted to a wall and secured by an electro-lock from an old run-out patrol car (http://www.santacruzgunlocks.com/locks/pumpgun.html). The electro-lock is designed to run off 12v power from a vehicle.

What I want:

1. Power the electro-lock in the house.
2. Have the electro-lock on a battery back up (if the power goes out in the house, the electro-lock can still still be opened)
3. Use a keypad to activate the release of the lock.

I don't know a whole lot about electronics, but I do know I'm going to need to convert my homes 120 A/C to 12v D/C to get the electro-lock to let go of my shotgun :-). I am wondering if this could be accomplished by using something like this: http://www.apc.com/products/resource...otal_watts=200

Could I just bypass the external plugs and run the 12v power for the electro-lock right off the battery inside this UPS? Would the UPS keep the battery charged after its used and the battery supply the 12v I need? The electro-lock will very rarely be used, and I don't think it will draw much of anything while just sitting there.

If the above will not work, can you point me in the right direction for something that would work?

If I can get the thing powered. Do you see any reason this wouldn't work for releasing the electro-lock? http://www.camdencontrols.com/pipeli...eet_Sept09.pdf

Thanks for any help!

nap

does that UPS have a 12V battery in it? If it does, you could probably do what you want. Have you looked for a 120vac powered 12vdc ups? That might be more simple. It would also likely be smaller as well.

exiledgator

A UPS should power your keypad and lock for a while. (24 hours?) It would depend upon the size of the battery in the UPS and the draw of your dc components. I can't imagine they'd use even 1 amp (plus loss from conversion).

A UPS like you linked, plugged into the wall with the proper 12v transformer/power supply(ies) should be all you need.

IMO.

nap

you missed the question. He wants to tag power from the battery and basically use the UPS as a charger for the battery. It's overkill but because they are relatively cheap, he may not be able to source a 120vac to 12vdc power supply/UPS for less.

since the lock is power unlock, it will draw nothing until he wants to remove the weapon. The keypad uses a non-volatile memory for user combination storage so the unit should have an extremely low current draw (if any at all) unless being used to activate the lock (then it is 500 mA) . As such, the battery would retain an adequate charge to be able to operate the system for a considerable time but to know with certainty, one would have to know the current draw of the lock plus the rating of the battery and any other current draw to be able to figure any sort of back up time and still be able to operate the lock.

rdiggidy

Gentleman,

Thanks for the responses!

@NAP: You got it. I'm wanting to bypass the plugs on the UPS and go straight for the battery, just like you described. This UPS' can be had brand new for about $40 on Ebay. I don't mind spending more if you guys are suggesting an alternate setup, but I thought this might be a fairly easy solution to my needs.

It sounds to me like you're saying it would work, but the amount of time the battery would last would be dependent upon the battery specs and the draw of the actual lock.

The draw of the lock is 2.1 - 2.4 Amps per unlock. Lets say the battery used was this one: AGM, 12V, 7.5AH L- 5.94 W- 2.56 H- 3.66 Terminal Type: T1/T2

I live in the city, so the power RARELY goes out (once that I can remember in the last year and it was out for about 20 minutes). The chance of me needing to get to the shotgun and the power being out at the same time are REALLY slim, but better safe than sorry. So if the battery can last 2-4 hours and offer me 1 unlock, that's all I need!

So, it should work right? If the answer is yes, then I guess my next question is: would it just be smarter to get an AC to DC converter and plug that into the UPS?

If you recommend doing the AC to DC converter would this be enough juice: http://www.amazon.com/Wagan-Amp-12V-...ref=pd_sbs_t_1

Or would you go bigger?

Thanks again for the help!

LyonsElecSupply

You could always get Emergency Exit light batteries.

They make a 6 Ah 12v battery which should give you decent run time.....or you could make a bank (3-4 in parallel). (They are sealed non-spillable batteries)

__________________
"Do it right the first time and avoid duplication of effort"

Your AHJ/Inspectors ALWAYS have the final say on ANY electrical code issue.
If in doubt, contact a licensed, experienced, reputable electrician to perform the work.

joed

You could get a whole emergency light. That way you have a charger as well and the light will come when the power is off so you don't shoot the wrong person. Just make sure you get one that is 12 volts. Some of them are 6 volts.

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LyonsElecSupply

Emergency lights are only rated for 90 mins of continuous run time......

__________________
"Do it right the first time and avoid duplication of effort"

Your AHJ/Inspectors ALWAYS have the final say on ANY electrical code issue.
If in doubt, contact a licensed, experienced, reputable electrician to perform the work.

EvilNCarnate

APC UPS's test the battery from time to time, the additional load of the lock could cause it to think the battery is bad and then it will start beeping. As well many of the older ones will just shut off after the battery has been in an error state and drained. I would recommend not wiring off the battery supply but rather using it as it was intended. Instead just wire the lock to a 12v supply. Go search for an "AC to 12v DC converter" or just click the link. Ive used the ones for a car adapter as a quick and dirty supply for testing car stuff in my garage.

Now granted if the power goes out you would be wasting a good amount of power converting the dc to ac and back to dc with a ups... so you could tap the battery and use a relay so when the ac is lost your ac/dc converter circuit switches and powers direct from the battery. Using the converted DC to keep the relay open and having it collapse to the other circuit at loss of power would keep the APC self test from detecting the battery load difference.

nap

right, continuous. The OP is talking about an electrically operated latch that draws only when activated. That means, unless he triggers the latch, the only draw will be the very minimal draw from the controller. It should last a long time in that condition.

nap

the latch does not apply a load unless activated. There is a minimal draw (if any) from the controller unless it is being activated

.

joed

You could remove the lamps then and just use the charging system.
You could replace the lamps with LEDs and it would probably run days.

All we are looking for here is a 12 volt power source and something to keep a battery charged for use in the event of a power failure. You could use a 12 volt car or RV battery and the battery maintainer to keep it charged if you wish.

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Do not PM with questions that can be asked in a forum. I will not respond.

rdiggidy

@Joed, I wish I read your suggestion earlier today...I like the 12v battery with a battery tender on it....that is probably the simplest solution and I have a battery tender already. I never thought of it :-(

But today I already order the stuff for the UPS with the AC to DC converter method.

Got: http://cgi.ebay.com/APC-Back-UPS-CS-...ht_2013wt_1139

and

http://www.amazon.com/gp/product/B00...ef=oss_product

and

http://cgi.ebay.com/ws/eBayISAPI.dll...ht_1892wt_1139

Total cost was under $50 with shipping and I think it'll work.

Once I get it all in (and hopefully working) I'll let you guys know how it works!

Thanks again for all the suggestions!