Wiring a Siren or Strobe Light to your Driveway Alarm

Many people who have discovered the advantages and practicality of using a driveway alarm to monitor driveway or laneway visitors often begin to wonder how to expand on their system.  For some they require a louder and more noticeable alert, while others require a deterrent to would-be-thieves and vandals. A strobe or siren work very well in both situations because they are more noticeable and less likely to be missed by someone with hearing difficulties, and are a signal to thieves that someone has noticed their presence. Whether you are wiring up a strobe light or a siren you will follow the same steps.

1. Make sure you have all the materials you will need
   • Driveway Alarm with a NO dry-contact output
   • A suitable siren or strobe
   • Power Supply
   • Wire
2. Connect the wires
3. Test your system

First you have to make sure that you have all of the materials you will need. The most important factor here is the ownership of a good quality driveway that has a Form “C” relay output or a normally open “NO” dry-contact output. A Form “C” relay output simply means that it can do both NO and NC connections. A normally closed output will not work in this situation as it will cause the siren or the strobe to only turn off when a driveway alert has been received.

You will then need a siren or a strobe. There are very many different varieties of both. A few options that are good for use with driveway alarms can be found here: http://www.absoluteautomation.com/sirens-and-strobes/.
There are many different sizes of sirens.  The larger the siren the louder it will be. Those who work in a noisy manufacturing shop might wish to choose a louder and larger siren than those who work in a retail store or restaurant. There are several different colors of strobe to choose from.  For those who wish to deter criminals might prefer the boldness of red while those in an office might prefer the softness of blue.

Depending on the size and power of the strobe or siren that you choose you need to choose an appropriate power supply.  The siren or strobe will specify what it needs; most require a 12 Volt power supply. Some driveway alarms have a 12V output; in this case an external power supply is not necessary. You then need to find out how much amperage you will need.  Again, your siren or strobe will specify how much it needs. If you are only using one strobe or siren you will only usually need a 500mA or a 1 amp power supply.  If you wish to use more than one, be sure to add the amount of amperage each will need. As a general rule you can never have too much amperage available, but voltage needs to match your requirements (too much may “smoke” your siren or strobe).

You then need to calculate how much wire you will need. The siren and power supply will come with a minimal amount of wire, but this will only be useful if you wish to have your driveway alarm chime right next to your siren or strobe.  Any low voltage wire will be suitable. Be sure to first place everything where you would like them to be so that you can measure out how much wire you will require. It is always helpful to have a few extra feet for unplanned difficulties.

Now you should be ready to wire everything together.  Run the red positive wire from your power supply to your siren or strobe and the black negative wire to the connector on your driveway alarm labeled “NO” for normally open. Then you need to run a black negative wire from your siren or strobe to your driveway alarm connector labeled “COM”.

A helpful visual is available here http://knowledgebase.absoluteautomation.com/drivewayalarm-accessorywiring/

The final step is to test your system before putting it to work. If you do encounter problems run through these steps again to see if something was missed.

When you are purchasing your driveway alarm accessories be sure to purchase from a reputable vendor that has a working phone number and better yet, free tech support. This may mean that you are paying more than at a bargain retailer; but you then have the peace of mind, technical support and ability to return items that are faulty under warranty or return items that were unused within 30 days.  Calling in before you make your purchase is an easy way to monitor how quickly you are able to speak to somebody, a service like this is very valuable when you have a problem.