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I got a siren! Answered

A little over a month ago, my dad got a siren on eBay. It's the Wolo Model 345, about halfway down the page. Note: if you want one, go through eBay, Wolo wants $64, but this was brand-new for $20. It's not Instructable-worthy, and I don't have enough pictures to make a Slideshow, so I'm using the Forums for their original use.

We were originally going to put this on my mom's ZAP Xebra, because it's completely silent and we wanted a way to warn walkers of her approach, but she didn't like it, so I got it to put in out Ford Courier. Since it's electric, I only go 39 in a 40 mph-zone to save range, so I'm often cut off by people going 45.

Being electric, the truck has no radiator, just a flat plate of steel. We were already going to paint it black, so we mounted the horn speaker in there.

There is an instrument bay overhead, so I stuffed the control box inside an empty slot. Eventually I'll take off the plastic case and mount it in the aluminum sheet to make it much cleaner, but this is fine for now. There were already two extra switches that did nothing, but already had an always-hot line running to them, so I wired it in to that.

It can do sirens, animal noises, or a PA. I'm leaving it set to a police-style siren, so if someone cuts me off, I can just flip the switch and give a short blast, then watch them look around for the police car. If I have more time, I can just use the PA to yell at them.

Other potential use: I'm going to make a CD of engine sounds. That way I can make my electric sound like an idling Harley at a stoplight. Or a turbine engine. Or a semi. Or a whatever.


LOL, if somebody cuts you up, follow them.

When they park, roll silently up and then go VRRROOOOMMMM!!!

And make sure you have your video camera handy.

My first Mini had a pretty feeble horn, which went honk. I splashed out on a pair of air-horns, which only just fit under the bonnet. I'm not sure how powerful they actually were, but the headlights dimmed when I pressed the button...

The air horns are still in the garage, they'll probably go on the other electric truck.

Heh, just found this topic. Air horns are now tucked behind the front bumper on my Ford Escort.

No silly! If someone cuts you ~~up~~ off, then you follow them, park about a block away from their house, and when they come out the next morning, they will be missing their tires.

>Stifles laughter< People talking on the phone and all. >Didn't work

:-( Your link to "ZAP Xebra" tells me it is FORBIDDEN for me to see it.

Such are the dangers of hotlinking. :) Should work now.

Shouldn't an electric car charge it self? Since an alternator?

It can but ONLY if it ALSO uses some gasoline or other form of energy to supplement the losses in conservation.

Laws of thermodynamics

An electric car can't charge itself (except for recovering a little energy with regenerative braking, but I suspect that's not what you mean), it's impossible.

Thanks for the quick reply...I answered a very similar question a few months ago, and created a fairly satisfactory answer. I saved it, and I have copy-pasted it below.

It would break the laws of physics. Let's say that you have an electric motor and a generator, such that the motor turns the generator and the generator powers the motor. All of your ideas basically boil down to that. If both the generator and the motor were 100% efficient, then ALL of the rotational force put out by the motor would be converted to electricity by the generator, and ALL of the electricity put out by the generator would be converted to rotational energy by the motor. This is physically impossible, due to friction, electrical resistance, and other inefficiencies, but let's pretend we've just broken that law, and move onto the next problem.

If you try to "tap in" to the electricity put out by the generator, then the motor will have less power to use, and will put less power to the generator. Let's say that you tap 25% of the power put out my the generator. This leaves the motor with only 75% of the original power. The next time around, another 25% is removed, leaving only 75% of 75%, or 56.25% of the original power, to run the motor. Thus, every time around, you lose power, until the amount remaining in the system is effectively zero. It's actually an exponential curve that approaches zero without reaching it, but it effectively reached zero very quickly.

As you can (hopefully) see, drawing power from a closed loop will cause it to slow down, as will ANY inefficiency below the theoretical maximum of 100%. Even an efficiency of 99.999999999% will eventually slow down and stop the system, without drawing out any power.

I hope I have sufficiently explained this, and haven't just confused you more. We have two electric cars, and we get asked this question all the time. It's difficult to explain to someone who doesn't just logically "get it," no offense intended toward you.

whimpy, whimpy, whimpy

Hefty, Hefty, Hefty!

ZOMFSM!! That's cooler than my bud's car horn...

haha great work!

weeeoooh! I want my electric ranger already!

. Using a siren that sounds like what the police use is probably illegal. . But it would be extremely funny to see their heads whipping around while they jam on the brakes. If the penalty is not too great, I might be willing to risk it.

If the penalty is not too great, I might be willing to risk it.

Do it.
Pics/video is needed.

Siren #8 sounds like a car alarm, maybe I'll use it.


9 years ago

I still love your truck...