The Siren Board

I was heading to work this morning on a bus, and we had to stop because there was an emergency going on somewhere, and out of nowhere, this ARROW ambulance (Not shaped like an arrow, it's one of the companies in town) comes by with the lights & sirens on, and instead of a rotating lightbars & regular flashing strobes, this ambulance came equipped with nothing but pure LED lights! It was cool to watch although I only got to see the ambulance for only like 5-10 secs.

LEDs are the future for warning lights. Let's see: LEDs last much longer, they draw less current, and the colors are very intense. The only downside is they're expensive, but that's starting to change already.

Cleveland has had a few for a year or 2 now.

and a few weeks ago, i saw an Akron fire department ambulance with LED's:


(sorry its a bit blurry)

all the ambulances here are brand new just a new ship ment a fleet of 7 and all have LEDs its realy cool to seem them cuse all the out side lights are white covers with red LEDs

Uh, should we flip the slide next time? I was looking at the signs and thought it was a city in Russia or something.

Jim_Ferer wrote:Uh, should we flip the slide next time? I was looking at the signs and thought it was a city in Russia or something.

that pic was taken looking at the sideview mirror, besides, the ambulance is the main attraction of that photo

Blue light is more noticeable to the human eye than red.
Also stands out in background which is often red and clear lights.

Incandescents, even halogen, do not produce blue well.
LEDs blues are so rich and pure.

We only have red LEDs. Blues are too expensive.

Our LEDs have a clear case and black background.
This creates the best contrast when lights are off between flashes.
They turn on and off INSTANTLY.

They flash one second on steadily, one second off. But during the OFF phase they rapidly flicker at half the Opticom preemption frequency. Together they create the preemption frequency, which sometimes works some signals - but never the signal at a huge busy intersection with a 500 foot long median before the intersection - where we need it most.

One of our lightbars has 26, count 'em, 26 flash patterns!
It's a joke. Best is simply ALL ON/ALL OFF - ALL ON/ALL OFF.

The back LEDS can be an arrow stick.
But we never use them as such.
If we correctly direct someone, and they have an accident, they may blame and sue us.
Though we be right, we spend a fortune to win the case.

Moral: Never direct anyone. Just protect yourself.

Both the Oregon State Police and the Salem PD appear to be converting to clear-cased blue LED light bars, although most of them still have skinny blue strobe bars with small red halogens on the back. They are much more noticable than the strobes and the color is more intense because it is monochromatic, rather than simply filtered with colored plastic. In Europe and most other countries, emergency vehicles use blue lights because they cannot be mistaken for brakes or traffic signals. Notable exceptions are Japan, various places in the Middle East, and New York, which all seem to prefer red.

Blue is best for visual detection both to stand out and also the retina
detects blue better for some reason.

But I like red color better.

My favorite was red, clear and blue on a lightbar.

In heavy snow, we saw orange from red beam crossing white
purplish red & blue
greenish blue & white

In some American places, funeral vehicals have PURPLE!

Light bars come with the following lights avalible:
Red
Blue (in some states, They are only assigined for Police, Example: Maryland)
Green
White
Amber (yellow)
Purple (disignated for a funeral vehicles only)