Newbie needs help adding on/off switch for peripheral

[DrakeTungsten]

I'm finishing my cockpit cabinet and I bought a police-style beacon to put on it. The beacon doesn't have an on/off switch. The only means of controlling the power is to plug and unplug it. I would like to add an on/off switch to it. I got some advice (and possible future help) from a friend, but would like a second opinion on his idea, because electricity scares me.

I bought a switch for this which will be spliced  into the beacon's existing power cord. Unfortunately, the switch is rated at 12v DC, but the label on the beacon's plug says that its output is 12v AC. The fact that it uses AC surprised him, and I found that it is harder to find switches rated for AC. Googling around tells me that generally it's safer to use a switch rated for DC in an AC device than the other way around, so I probably don't have much to worry about. Should this switch be OK for my beacon? What's the worst that could go wrong?  Are there any pitfalls to watch out for?

[DaOld Man]

It is strange indeed that the beacon needs 12 VAC. Are you sure it's not 120 VAC?
As far as the switch, it should be rated for ac voltage, but a dc one would probably work, but any switch rated for ac voltage will work (even a wall type  light switch).
If the beacon is in fact 120 VAC, I would not use a dc rated switch.
And in either case, switch needs to be rated for at least the amount of voltage you are switching.
Example: A 120 VAC switch will be just fine switching a 12 VAC load, but a 12 VAC switch should not be used to switch a 120 VAC load.
Also, the switch should be rated to handle at least the amount of amps the load pulls. Example a switch rated at 5 amps will be just fine switching a load of 3 amps. The load should not be higher than switch amp rating.
Clear as mud?

[drventure]

It is strange indeed that the beacon needs 12 VAC. Are you sure it's not 120 VAC?

+1

When you say "Plug and unplug it" do you mean into a wall socket, or into the lighter socket in a car?

If it's a lighter socket, that's 12vdc, and just about any automotive switch will work (but pay attention to the load as DaOldMan says).

If it's a wall socket, then it's all but certainly 120vac, and of that's the case, you need to be more careful. Easiest and safest would be to just buy an extension cord with a switch in it and plug things up.

[DrakeTungsten]

It plugs into a wall socket. Both of us have read the information on the plug and we both read "12 volts AC".

At first, I did look for an extension cord with a switch, but couldn't find any. But now that I bought a nice-looking switch with a flip-open safety cover, I would really prefer to use that.

[DrakeTungsten]

I should clarify: The 12 Volts AC is listed as the output. Input is AC 120 Volts.
The full info:
Input: AC 120V,  60 Hz, 103mA
Output: AC 12V, 830mA, Max 10W

And by "splicing", I mean that I (or hopefully my friend) will cut the power cable in the middle and install the switch there. The existing cable is not long enough to reach where it needs to go regardless if I'm using a switch or not, so we are going to use additional cable (is speaker wire/cable OK for this?) to attach the switch to both ends of the cut.

[rCadeGaming]

You should say it has an "AC adapter" rather than the just a plug.  Anything AC or DC should work for that, as long as its rated at for least 12V and 830mA (0.83 Amps), or 10 W. 

Watts is a measure of total power, found by multiplying the voltage and the amperage together, 12V x 0.83A = 9.96W.

[DrakeTungsten]

Sorry for the confusion and thanks everybody for the comments. My only remaining question is could I use speaker wire for this?

[DaOld Man]

You could probably use speaker wire, if it is on the 12 volt side of the power adapter. If it is very small speaker wire, make sure it doesnt get warm to the touch after the light has been on for a minute or so. If it does you need a bigger speaker wire.
Just a little primer about using wire:
The size of the wire (AWG, or how big the conducting part is), determines how much current the wire can carry. The insulation around the wire determines how much voltage it can safely handle.
Since the light only draws slightly less than an amp and the voltage is only 12, speaker wire should work.
If the speaker wire is about the same size (or bigger) than the wire going between the adapter and the light, then you should be A-OK.
Good luck with your project. Sounds interesting. Any pics of your cab?

[DrakeTungsten]

I plan on posting pics in a week or two. They might be more helpful in a "here's what not to do" context, but since I found few examples of cockpits that I liked and found no plans at all, somebody might find my experience helpful.