Using keypad to open 12v electronic gun lock
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Using keypad to open 12v electronic gun lock
Hey all - I think this is the right place for this but feel free to move if I'm wrong.
In my quest to provide a method of securing a rifle or shotgun in my safe room in a secure but quick-access manner, I've bought a Santa Cruz SC-5 system like this one.

I also purchased a lovely Chinese keypad to open the locking mechanism. I've got lots of 12v in the safe room, so I figured all would be copasetic.
Illuminated Metal Keypad Access Control 5 Free RFID Cards 5 Free RFID Tags | eBay
So today, while waiting for the gun lock to arrive in a few days, I got to trying to read the keypad manual, and under Lock Relay it reads 2A. Hmm...did some quick research and supposedly the Santa Cruz lock requires 2-4A to operate.
And thus I realize that I may be in a bit of a bind. I suppose I could certainly try it when it arrives in the hopes that perhaps both are conservatively rated in how many amps they are rated for; on the other hand, is there any chance I could wire this in such a way that I could somehow get the lock all the power it requires without being restricted by the keypad? Sure doesn't seem possible to me but you guys are the geniuses! Here's a schematic and spec sheet for the keypad:


I did some poking around and apparently all the sub-$100 keypads I could find (all Chinese of course) only do 2 amps...so I am hoping there is some way to make this work!!
Any ideas, all?
Many thanks!
In my quest to provide a method of securing a rifle or shotgun in my safe room in a secure but quick-access manner, I've bought a Santa Cruz SC-5 system like this one.

I also purchased a lovely Chinese keypad to open the locking mechanism. I've got lots of 12v in the safe room, so I figured all would be copasetic.
Illuminated Metal Keypad Access Control 5 Free RFID Cards 5 Free RFID Tags | eBay
So today, while waiting for the gun lock to arrive in a few days, I got to trying to read the keypad manual, and under Lock Relay it reads 2A. Hmm...did some quick research and supposedly the Santa Cruz lock requires 2-4A to operate.
And thus I realize that I may be in a bit of a bind. I suppose I could certainly try it when it arrives in the hopes that perhaps both are conservatively rated in how many amps they are rated for; on the other hand, is there any chance I could wire this in such a way that I could somehow get the lock all the power it requires without being restricted by the keypad? Sure doesn't seem possible to me but you guys are the geniuses! Here's a schematic and spec sheet for the keypad:


I did some poking around and apparently all the sub-$100 keypads I could find (all Chinese of course) only do 2 amps...so I am hoping there is some way to make this work!!
Any ideas, all?
Many thanks!
#2
I can help you out but I can't see/read your info. Post the make and model so I can get the info.
The long and short of it is.... you should use an aux. relay to operate the lock. Bosch relays, like in the pic below, are available everywhere mobile electronic equipment is sold. That relay would do the switching and save your keypad.
The long and short of it is.... you should use an aux. relay to operate the lock. Bosch relays, like in the pic below, are available everywhere mobile electronic equipment is sold. That relay would do the switching and save your keypad.

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Hey PJMax - thanks so much! This really makes great sense. In fact, it seems the keypad creators took this into account as there is an "electric lock relay output" on the board.
Let me apologize for my earlier pictures - they are thoroughly unreadable though the originals were fine. Let me try again - that may be the best way!
I think I've pretty much figured out the wiring, but just to be sure - would I wire the lock right to the "electric lock relay output"? And I assume this would be NC...but I'm certainly not certain
Trying again...hopefully readable this time!

Any idea which model number Bosch relay would work for this?
Many, MANY thanks!
Let me apologize for my earlier pictures - they are thoroughly unreadable though the originals were fine. Let me try again - that may be the best way!
I think I've pretty much figured out the wiring, but just to be sure - would I wire the lock right to the "electric lock relay output"? And I assume this would be NC...but I'm certainly not certain

Trying again...hopefully readable this time!


Any idea which model number Bosch relay would work for this?
Many, MANY thanks!
#4
Below is the wiring diagram you'll need to follow. The relay on the lock board activates the Bosch/AUX relay and it operates the gun lock. You can use any 5 pin mobile relay. Bosch is the most common but there are at least ten different company names on them. If you call someplace to see if they have them you'd ask for a Bosch relay and they might say they have the xxx version which is fine. That relay is rated for 25A of switching so it'll last a long time.

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Seriously, this is amazing - thank you so much, PJM!! It really says a lot about people that I can drop in here from out of nowhere and you would even go so far as to draw me a really nice diagram. There are good people in this world!
Just got back with a relay and some 18-gauge wire - the lock is estimated to arrive on Thursday so I'll report back with my results!
Many, many thanks - this is the second time I've used this forum for help and both times I've been absolutely amazed at how friendly, knowledgeable, and helpful it has been. I think you really have renewed my faith in humanity!
Have a great night all!
Just got back with a relay and some 18-gauge wire - the lock is estimated to arrive on Thursday so I'll report back with my results!
Many, many thanks - this is the second time I've used this forum for help and both times I've been absolutely amazed at how friendly, knowledgeable, and helpful it has been. I think you really have renewed my faith in humanity!
Have a great night all!
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Hey all - I was finally able to get the lock mounted and everything wired up tonight. Unfortunately, when I made the last connection, nothing happened - the keypad was dead. I'll go back and double-check the wiring again tomorrow - just too darn beat tonight - but is there a way I could check to see if my Chinese e-bay-special keypad is at fault?
My multimeter says there's 12.8VDC between 86 and 30, so the relay is getting the power it needs. I used 18-gauge stranded wire and crimp connections or wire nuts throughout.
Many thanks, guys - I have faith!
My multimeter says there's 12.8VDC between 86 and 30, so the relay is getting the power it needs. I used 18-gauge stranded wire and crimp connections or wire nuts throughout.
Many thanks, guys - I have faith!
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Ok duh, so after having a bit of time to think it over, obviously the keypad is nothing more than a glorified switch and needs power of its own. Would it be sufficient to run the same + and - that's going to the relay into the keypad itself?
Sorry guys... been a LONG day!!
Sorry guys... been a LONG day!!
#10
Yes.... the keypad needs power. I was just illustrating the beefed up part for lock power.
The additional connections are shown below.
The additional connections are shown below.

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Alright - update! Got the keypad powered and it came right on. Programmed it up, then gave it the code to unlock but the lock didn't open; instead, a loud buzzing came from the relay for the two seconds that the lock should have been open. I checked all the wiring and it seems to be correct! Any ideas?
Many, many thanks, guys!
Many, many thanks, guys!
#13
I'm guessing if you disconnected the lock from the relay that the relay would operate normally.
That wold tell us that your power supply is not maintaining voltage.
What did you use for a power supply ?
That wold tell us that your power supply is not maintaining voltage.
What did you use for a power supply ?
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Okay, I just disconnected 87 and it didn't buzz at all. My power source is large 12v batteries; i tried two different ones and they both buzzed. Meanwhile, the voltmeter showed them drain just 10 mA while it was buzzing; also, before I hooked everything together I touched the lock wires to one of the batteries and it worked perfectly. I've got my voltmeter right here - anything I can try to figure out this riddle?
Again, I am so grateful for your patience and help!
Again, I am so grateful for your patience and help!
#15
Try connecting the C and NO wires coming from the module together.
The circuit is acting like the module is starving for power. Did you use decent size interconnect wire..... like maybe #18 ?
The circuit is acting like the module is starving for power. Did you use decent size interconnect wire..... like maybe #18 ?
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I just put a wire between the 85 and 30 terminals, and the same buzz happened! Hmm... I did use 18 awg stranded throughout, even to and from the board in the keypad...
#18
I can count the defective Bosch type relays I've had on one hand and I've used hundreds of them.
When you take 87 off the relay does the relay click when it's supposed to when you activate the code ?
It's a simple basic circuit. Is there a polarity to the lock and is it correct ?
When you take 87 off the relay does the relay click when it's supposed to when you activate the code ?
It's a simple basic circuit. Is there a polarity to the lock and is it correct ?
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Hmm...when I disconnect 87 there is no "click" in the relay, just a click from the keypad, which I believe we've determined is working as usual. The lock doesn't have polarity.
This is just strange.
So get this - just for fun I put the voltmeter between 30 and 87; turns out there was like 8 volts going through it - except when the keypad closed the circuit! Then it dropped to zero. 87a same thing, but with 10 volts. I could be wrong on which was 8 and 10 - it's been over ten minutes now!
So heck, it just seems like this relay doesn't want to do what it's supposed to do. Shall I try a new one tomorrow?
PJMax, thank you SO very much for your help - I deeply appreciate it and when this thing is working soon I will owe it all to you!!
This is just strange.
So get this - just for fun I put the voltmeter between 30 and 87; turns out there was like 8 volts going through it - except when the keypad closed the circuit! Then it dropped to zero. 87a same thing, but with 10 volts. I could be wrong on which was 8 and 10 - it's been over ten minutes now!
So heck, it just seems like this relay doesn't want to do what it's supposed to do. Shall I try a new one tomorrow?
PJMax, thank you SO very much for your help - I deeply appreciate it and when this thing is working soon I will owe it all to you!!
#21
Try reversing the leads on 85 and 86. Maybe you got a relay with a diode in it.
There are some relays like that .... that are used for special purpose.
What's the number on the relay.
There are some relays like that .... that are used for special purpose.
What's the number on the relay.
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Alright! Reversed 85 and 86. No buzz, but no voltage between 87 and 30 either. I tested the resistance between 85 and 86 - just 40? Weird. The relay is a Littelfuse FLR27.Should I get a replacement?
By the way, touching 30 to 87 opens the lock perfectly - so we certainly know that it's not the lock or the keypad! Hooray!
By the way, touching 30 to 87 opens the lock perfectly - so we certainly know that it's not the lock or the keypad! Hooray!
#24
That number is a Littlefuse 5 pin thermal flasher unit. Not a relay.
What store are you buying that out. We can check to see what they carry that will work.
What store are you buying that out. We can check to see what they carry that will work.
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Thank GOD! Was coming a little unglued trying to figure it out. I got it at O'Reillys - if they don't carry one I'll just return it and find one somewhere else. Thank you!!
#26
List: Replacement Relays (Universal) | O'Reilly Auto Parts
Optronics® A715A - Light Relay | O'Reilly Auto Parts
BWD R3177 - Relay - Multi-Use | O'Reilly Auto Parts
Sometimes they're known as driving or fog light relays.
Optronics® A715A - Light Relay | O'Reilly Auto Parts
BWD R3177 - Relay - Multi-Use | O'Reilly Auto Parts
Sometimes they're known as driving or fog light relays.
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Hot dang!!! Works like a charm!!! AND I got 7 bucks back in change!! It was pretty tricky of them to make a flasher with exactly the same layout and appearance...I am SO thankful you figured it out, PJMax!! Let me clean it up a little and I'll post a pic. Might be Tuesday...
Let me say again thank you SO much for the help!! New favorite site ever.
Let me say again thank you SO much for the help!! New favorite site ever.
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Well...it is finished! It really ain't much to look at but it is absolutely exactly what I needed and pure utility.

I hated to have to run the wires and mount everything outside the drywall, but it's concrete on the other side so I didn't have any choice. Again, pretty it ain't, but it works like a dream. Of course, anybody with any sense could start cutting and splicing wires until it opens, but if anybody has access to this area in the first place, they are meant to be there.
PJMax, thank you so much for your infinite patience and problem-solving! Would have been completely impossible without you.
Thanks again!!

I hated to have to run the wires and mount everything outside the drywall, but it's concrete on the other side so I didn't have any choice. Again, pretty it ain't, but it works like a dream. Of course, anybody with any sense could start cutting and splicing wires until it opens, but if anybody has access to this area in the first place, they are meant to be there.
PJMax, thank you so much for your infinite patience and problem-solving! Would have been completely impossible without you.
Thanks again!!