Converting Whelen 900s/Similar Scene lighting to LED?

[eporter]

I like the idea of using the existing wiring as it's already run. I've thought of adding relays where the strobe controller is. Apparently this is a common emergency vehicle upgrade practice when upgrading old strobe housings to newer LED housings. The LEDs just need constant current, as they've got the flashing built in to the light head. So you add relays that just turn on the LEDs. That would work great whether it's a flashing LED light, or a nice work light for seeing the BBQ.

So there are a lot of options out there for clear scene lights. It seems the "Gradient Scenes" have a "cross pattern optic" and others have the "strobe style" lens.

Mine are the older 97 series, and they've got 13 degree scene lights in them. I think the only difference between a clear Halogen Lens, and a Scene Light, is that the the scene light "Lens Assembly" has a second, inner diffuser added that gives it the angle. This diffuser slides onto the mounting screw bosses with snap rings. I had to remove one to clean off the algae build up inside the lens. It's a Pacific Northwest problem...







I just ordered 4 more of these:



I plan to put the cross pattern optic ones on the front. Maybe someday I'll replace those with plates and flush mount LED spotlights of some sort.

I think anything with refractory lens patterns built into it will work ok. At some point it's all splitting hairs. Do you all have the strobe style scene lights, or the style that's just vertical lens lines?

Anything is better than the old, crusty-duct-tape covered lenses on mine...

 

[patoz]

I just ordered 4 more of these:

View attachment 327552

I plan to put the cross pattern optic ones on the front. Maybe someday I'll replace those with plates and flush mount LED spotlights of some sort.

I think anything with refractory lens patterns built into it will work ok. At some point it's all splitting hairs. Do you all have the strobe style scene lights, or the style that's just vertical lens lines?

Anything is better than the old, crusty-duct-tape covered lenses on mine...

I hear ya on the 'crusty-duct-tape covered lenses'! My 1993 had the old Model 97 lights also, so I ordered a new single lens to test with various bulbs. That lens (like the ones you just ordered), used with the intended Halogen bulb, produces a cross shaped (+) beam pattern, which is pathetic IMO for use as a scene or area light. The red lenses had the same pattern, so I don't believe these are 'scene' lenses even if they are labeled as such. The cross pattern projects warning light both in a horizontal pattern, i.e. intersections, and in a vertical pattern, i.e. hills and valleys.

Back in the 80s and early 90s there may not have been any actual 'scene' lenses, and they were all the same.

This is the lens I'm looking for. It's a 900 Series Gradient Opti-Scenelight. Notice it has no horizontal or vertical bars, but it does have an even dispersing texture on the inside of the lens. It is designed to be used with a 27W Halogen bulb.

The other problem I see with using the 900 series halogen lights as work lights for camping is, they are designed to light a big area for a good distance away from the ambulance, such as a vehicle in a ditch or the front yard of a house fire, etc. They project their light pretty much straight out horizontally, with no way to change the angle unless you add a special adjustable flange.

In a camping scenario, we generally don't need to light up the trees in the forest 100' away, but we do need to light the area immediately around the vehicle, and outward maybe for 30'- 40'. With the newer 900 Series Super-LED Gradient Opti-Scene Lights, Whelen addressed that problem and designed these so a certain amount of light is thrown directly downward, and the light has a 'top' side which must be mounted up.

Also just FYI, there is no such thing as 'strobe style scene lights'. Strobes (not LEDs) do one thing, and that is flash. They use high voltage and require a power supply we generally call a 'strobe pak'.

 

[eporter]

Good info there! Yeah, I don't need to blind everyone else camping, that's why I think a nice low glow might be ideal. Kind of like a truck with just marker/cab lights on.

What I meant to say was "strobe style scene light LENSES", that is to say the kind shown in the chart above. I think the difference between the older strobe light and scene light lenses is the second refractor lens panel in the assembly. That panel gives the 13 or 26 degree light angle, and would hopefully improve on the + pattern.

 

[patoz]

Good info there! Yeah, I don't need to blind everyone else camping, that's why I think a nice low glow might be ideal. Kind of like a truck with just marker/cab lights on.

What I meant to say was "strobe style scene light LENSES", that is to say the kind shown in the chart above. I think the difference between the older strobe light and scene light lenses is the second refractor lens panel in the assembly. That panel gives the 13 or 26 degree light angle, and would hopefully improve on the + pattern.

I have never come across any of those in the past, but that could be true. Warning light technology and their regulations are changing so fast, it's hard to keep up with all of it.

Did you see my review (post # 70, pg. 7 of this thread) of the Rigid Industries 1x2 65º DC Scene Light - White ?

I now have four of these and will be doing some more realistic testing soon. I want to temporary mount two of them on one side in the exact places where they would be permanently mounted, and then do some measuring out to known distances, while taking pictures from the top of the ambulance using a tripod and looking downward. I believe that setup will give the point of view for comparison purposes. It the previous test, I had them mounted on an open wooden 'T' shaped stand, but having them mounted on the side of a white ambulance should reflect even more light onto the work area.

My only probably with doing that testing right now is, my front yard is lit up like a football stadium due to the extra security street lights I pay for. And, my ambo/camper trailer is not street legal yet, and has no tag so it can't be towed to a darker location.

 

[eporter]

OK, so I did some testing with some LED Sign Modules. These go inside most outdoor illuminated signs these days, and are quickly replacing the old fluorescent tubes. They're weatherproof, and fairly cheap. Ideal scenario would be an RGB version that's dimmable & color adjustable.

Here are some pics of the older style lenses I have. Note that the red and the clear have the same pattern, but there's an added diffuser for the clear scene light version.

 

[patoz]

So the extra diffuser is basically flat and the 'C' rings are what's holding it in place, right?

Do you have any pictures or links to the LED Sign Modules you are testing?

 

[eporter]

Yes, the diffuser is held in w/ those snap rings. They make 13 and 26 degree versions of the diffuser. You could probably make a diffuser out of milk-plex translucent white acrylic and have decent results getting good glow from the LEDs.

I'm going for decent camp light over the ability to really illuminate an accident scene...

I used 4 LED sign modules. Each had 3 LEDs, so that's 12 5050 style LEDs per scene light. There are a ton of options for these modules, from cheap to quality. I'd get some from superbrightleds, they've got good quality.

RGB for color changing options, or warm white for a nice camp glow. They cost ~$2/module, so that's $8/scene light to add LEDs. Or add less modules to more light heads if you replace the red lenses w/ clear.
https://www.superbrightleds.com/cat/led-module-strings/

So here are some pics of the different lenses, with the LED modules installed. I used the red lens, a clear lens w/ diffuser, and the modern gradient lens.

**I'm having a lot of trouble uploading/linking pics here today. It keeps timing out/getting errors. I'll update this as soon as I can get it to work!**

 

[patoz]

I'm having trouble with the forum also. Apparently, it's still suffering from the DoS attack.

I looked at those LED sign modules and the problem I see is most of them are only 50Lm or less, which is nothing when your talking about useable projected light. Even the High Power ones are only in the 80Lm range which is still very little. If you use four high power ones in each lighthead that's a total of around 320Lm, which is not too shabby, but half of that is headed out into space unless you can find a way to direct it all downward to where you need it.

Don't get me wrong here, I'm not condemning your efforts by any means, I'm just playing the devil's advocate. I hope you do come up with a workable and economical solution to the common problem we ambo/camper owners all have.

What gets me though is, I'm a flashaholic (or so I've heard) and have all kinds of flashlights. I have some small LED lights that will fit in the palm of your hand and will light up my entire yard with enough light to read by. I have one in particular, which is just a little smaller than the size of a coke can and rated at 3,660Lm with a semi-flood pattern. It has three LEDs and reflectors. and will light up the entire block! One of these mounted on the side of an ambulance would be overkill for use as a work/scene light. So why is it so hard for us to find decent 12VDC LEDs to use for this function?

 

[tgreening]

So why is it so hard for us to find decent 12VDC LEDs to use for this function?

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[patoz]

Tom, you ain't right! :agree:

 

[tgreening]

Hey, got to make my incredibly valuable contribution.

 

[patoz]

Hey, got to make my incredibly valuable contribution.

 

[eporter]

So here are some pics from the other evening when I tested out the four LED-module arrangement in a 900 lighthead with the new style gradient (grid) lens, and the old style lens w/ snap-in diffuser.

I should do this side by side in a field to really show any differences, but I think my main take away from this is that the older style lenses work almost as good as the new ones. I think the gradient is better for diffusing/directing light lower towards the ground, but if you can find the old style clear lens for cheap on ebay like I did, then go for it.

Either way, adding the LED modules is a cheap add-on to existing scene lights and they use a fraction of the power. I'm going to try to find some RGB dimmable LED modules so that I can dim the light way down for late night camp use/basic visibility.

Fairly un-scientific, but you get the idea. Kind of hard to say which is "brighter" since the auto-exposure on my iphone camera goes all over the place.

Light pattern with new style 900 clear "Gradient" Scene Light lens:


Light pattern with old style 900 clear Strobe lens and extra snap-in internal refractor plate:


Then I propped the light up on the back of the ambo, at approx. scene light height & plugged it into a 12v power source.



Gradient lens:


Old style lens:


Gradient lens illumination:


Old style lens illumination:


Gradient lens from afar:


Old style lens from afar:


Visibility at the ground. It's probably a bit brighter from the light reflected off the white garage door.

 

[patoz]

They look like they are putting out a fairly good amount of light. As far as the minimum amount on the ground, some of the actual 'scene' lights are marked with the word 'Top' on the edge to indicate which way to mount them because the lenses have a certain degree of downward angle built into them. Did you check for that?

 

[eporter]

These have a top mark, and I'm 90% sure I had it the right way up. I did this all a few weeks back, so the details are fuzzy.

My main goal was to see the difference in light quality w/ the different lenses. I proved to myself that I can add LED modules to the scene lights and still have decent light.

3 or 4 LED modules use about 1/10th of the power of the 27w Whelen bulbs. So, I could have all 10 900-Series clear-lens-converted scene & warning lights on, and use about the same power as ONE scene light, and have tons of ambient light all around the rig. Could be cool...