Hobby small electronics guy?

[Construct More Pylons]

Hey guys!

I am trying to build a gun show alarm and am running into an issue. The goal is to have something connected to RCA cables, where a siren will go off if a cable is cut / unplugged. And I want to power it off of a 9v battery and have it switch activated to turn off and on. So far this is my shopping list (see below). Do I need some kind of DC relay? If so what would you recommend (bonus points for a cheap one on amazon).

• Yoodelife 9V Battery Clip Connector, 9 Volt Long Cable Connection Soft Shell I Type, Black, 5 Pack​

  https://www.amazon.com/Yoodelife-Battery-Connector-Cable-Connection/dp/B081ZRBDVW/ref=sr_1_5?crid=2LPPGZ4WO88OC&keywords=9v+battery+connector&qid=1652586418&sprefix=9v+battery+connector%2Caps%2C83&sr=8-5

• Otdorpatio Project Box ABS Plastic Black Electrical Boxes IP65 Waterproof DIY Electronic Junction Box Power Enclosure 7.87 x4.72 x2.95 inch (200x120x75 mm)​

  https://www.amazon.com/Otdorpatio-Waterproof-Electrical-Electronic-200x120x75/dp/B08N1DD5WJ/ref=sr_1_18?crid=3T9DKVTWL6ZHE&keywords=6%22x3%22x2%22%2Bproject%2Benclosure&qid=1652586451&sprefix=6%2Bx3%2Bx2%2Bproject%2Benclosure%2Caps%2C114&sr=8-18&th=1

• Wishiot 12V DC Black Mini Piezo Alarm Siren 110dB Insurance Safes Anti-Theft Alarm High-Decibel Buzzer for Car（Pack of 5）​

  https://www.amazon.com/Wishiot-Insurance-Anti-Theft-High-Decibel-Car%EF%BC%88Pack/dp/B086YKYKL7/ref=sr_1_5?crid=H1TT2RD25EDP&keywords=piezo+siren&qid=1652586379&sprefix=piezo+siren%2Caps%2C79&sr=8-5

• Poyiccot RCA Female Speaker Wire Adapter, Phono RCA Female to AV 2 Screw Terminal Female Video Audio Spring Press Type Balun Connector Adaptor for CCTV(4-Pack) (RCA Female)​

  https://www.amazon.com/Poyiccot-Speaker-Female-Terminal-Spring/dp/B077JK3QNG/ref=sr_1_3?crid=1RQEJZOL74TGN&keywords=rca%2Bfemale%2Bpost&qid=1652586301&sprefix=rca%2Bfemale%2Bposts%2Caps%2C72&sr=8-3&th=1

• APIELE 10Pcs Rocker Switch ON Off KCD1 Mini Round Toggle Switch SPST 2Pin Snap-in Design Car Boat Automotive with Wires Pre-Wired AC 6A/250V 10A/125V 12VDC​

  https://www.amazon.com/APIELE-Rocker-Switch-Automotive-Pre-Wired/dp/B08R5PLDBP/ref=sr_1_1_sspa?crid=1V5OKNUFS8JL1&keywords=12v%2Btoggle%2Bswitch&qid=1652586168&sprefix=12v%2Btoggle%2Bswitch%2Caps%2C80&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUThXSzRCQlpYNjRYJmVuY3J5cHRlZElkPUEwNjg3ODAzM0YzRjRaRE9XTkJKNiZlbmNyeXB0ZWRBZElkPUEwMjE0NDAwMVNLMkw2TUNVQkJNMiZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

 

[Bypass]

http://www.gunshowalarm.com/

 

[Construct More Pylons]

http://www.gunshowalarm.com/

And they are the reason I’m building. The tool 3 months to send me an alarm then the alarm was non functional.

 

[Bypass]

And they are the reason I’m building. The tool 3 months to send me an alarm then the alarm was non functional.

Wow!! That sucks man. Have they offered to send a replacement?

 

[User170512]

Feel like you're overthinking it. Just get something similar that IS available like a standalone door alarm and wire an RCA cable jack in place of the switch.

 

[cskiles]

Hey guys!

I am trying to build a gun show alarm and am running into an issue. The goal is to have something connected to RCA cables, where a siren will go off if a cable is cut / unplugged. And I want to power it off of a 9v battery and have it switch activated to turn off and on. So far this is my shopping list (see below). Do I need some kind of DC relay? If so what would you recommend (bonus points for a cheap one on amazon).

• Yoodelife 9V Battery Clip Connector, 9 Volt Long Cable Connection Soft Shell I Type, Black, 5 Pack​

  https://www.amazon.com/Yoodelife-Battery-Connector-Cable-Connection/dp/B081ZRBDVW/ref=sr_1_5?crid=2LPPGZ4WO88OC&keywords=9v+battery+connector&qid=1652586418&sprefix=9v+battery+connector%2Caps%2C83&sr=8-5

• Otdorpatio Project Box ABS Plastic Black Electrical Boxes IP65 Waterproof DIY Electronic Junction Box Power Enclosure 7.87 x4.72 x2.95 inch (200x120x75 mm)​

  https://www.amazon.com/Otdorpatio-Waterproof-Electrical-Electronic-200x120x75/dp/B08N1DD5WJ/ref=sr_1_18?crid=3T9DKVTWL6ZHE&keywords=6%22x3%22x2%22%2Bproject%2Benclosure&qid=1652586451&sprefix=6%2Bx3%2Bx2%2Bproject%2Benclosure%2Caps%2C114&sr=8-18&th=1

• Wishiot 12V DC Black Mini Piezo Alarm Siren 110dB Insurance Safes Anti-Theft Alarm High-Decibel Buzzer for Car（Pack of 5）​

  https://www.amazon.com/Wishiot-Insurance-Anti-Theft-High-Decibel-Car%EF%BC%88Pack/dp/B086YKYKL7/ref=sr_1_5?crid=H1TT2RD25EDP&keywords=piezo+siren&qid=1652586379&sprefix=piezo+siren%2Caps%2C79&sr=8-5

• Poyiccot RCA Female Speaker Wire Adapter, Phono RCA Female to AV 2 Screw Terminal Female Video Audio Spring Press Type Balun Connector Adaptor for CCTV(4-Pack) (RCA Female)​

  https://www.amazon.com/Poyiccot-Speaker-Female-Terminal-Spring/dp/B077JK3QNG/ref=sr_1_3?crid=1RQEJZOL74TGN&keywords=rca%2Bfemale%2Bpost&qid=1652586301&sprefix=rca%2Bfemale%2Bposts%2Caps%2C72&sr=8-3&th=1

• APIELE 10Pcs Rocker Switch ON Off KCD1 Mini Round Toggle Switch SPST 2Pin Snap-in Design Car Boat Automotive with Wires Pre-Wired AC 6A/250V 10A/125V 12VDC​

  https://www.amazon.com/APIELE-Rocker-Switch-Automotive-Pre-Wired/dp/B08R5PLDBP/ref=sr_1_1_sspa?crid=1V5OKNUFS8JL1&keywords=12v%2Btoggle%2Bswitch&qid=1652586168&sprefix=12v%2Btoggle%2Bswitch%2Caps%2C80&sr=8-1-spons&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUThXSzRCQlpYNjRYJmVuY3J5cHRlZElkPUEwNjg3ODAzM0YzRjRaRE9XTkJKNiZlbmNyeXB0ZWRBZElkPUEwMjE0NDAwMVNLMkw2TUNVQkJNMiZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

The primary issue that you are going to run into is this - the piezo alarm works when power is applied, but you need the piezo to work when the cable / power is disconnected...not applied.

1.) I would add a double-pole/double-throw relay - the coil voltage of the relay (12 vdc) would be applied through the RCA cables constantly.
2.) The common of the relay would would be wetted with 12vdc, and the (+) power wire to the piezo would be attached to the normally-open contact.
3.) The 12vdc(-) would tie straight from the power source to the negative lead on the piezo.
4.) If all possible, I would ditch the batteries for a power supply - Power Supply. If you think that readily available power is going to be an issue, you should look into alarm system batteries for homes - Battery.
5.) The rocker switches would need to break the power between the battery and the relay coil.


Not trying to commandeer your plan, just a couple of thoughts. Let me know if you have any questions...

 

[JBWJr]

Treat it like an e-stop circuit.
The plugs keep voltage from the relay unless removed, turning on the relay transferring voltage to the horn, until plugged back in.
Crude, but effective.

This is created using a freebie app on the Digi-Key electronics website. Just an FYI.

 

[Bypass]

You guys are smart. I couldn't read a wiring diagram to save my life.

 

[JBWJr]

Nah. Old.

 

[cskiles]

Treat it like an e-stop circuit.
The plugs keep voltage from the relay unless removed, turning on the relay transferring voltage to the horn, until plugged back in.
Crude, but effective.

View attachment 4290800
This is created using a freebie app on the Digi-Key electronics website. Just an FYI.

How would a plug stop the flow of electricity, unless it was disconnected? Voltage would have to applied to the relay coil to change the state of the relay, so wouldn't the voltage need to be continuous to the coil of the relay with the piezo feed on the N/O contact of the relay.

In an E-stop circuit, the 'stop' functionality is provided by breaking the flow of electricity - that would definitely turn a load OFF but in this case, the OP is trying to turn a load ON upon loss of voltage flow. Not being a smart-ass, am I missing something?