has two new products for 2008. One is the final frontier for LEDs. The other is a unique lighting solution for unmarked vehicles.
New from SoundOff is its GHOST line of Gen 3 LED emergency lights. The concept behind the GHOST lights is a full power LED warning signal when on and hidden against the background of the vehicle when off. Part of this “ghost” effect is the small size of the light, and part is the unique mounting locations and methods.
Each GHOST light uses 6 LEDs in a single row. However, each light can be split into different colors. For example, the GHOST is available with three red LEDs and three blue LEDs, or three amber and three white, etc. The GHOST is available in 32 different flash patterns. The desired pattern may be selected by simply grounding a lead until the correct pattern is displayed. While many departments want a particular pattern, once it has been set, this is seldom changed during the life of the vehicle.
The light itself is less than an inch tall and 4 inches wide. It is designed to be mounted outside the vehicle on the rear lip of the hood, where it will visually blend in with the windshield wipers.
SoundOff has designed three mounting options for the GHOST. The first is a permanent mount where the mounting bracket is simply bolted to the exterior or interior surface. The second is an adhesive mount, which uses 3M automotive-grade adhesive tape. This holds the light in place, in all types of weather, without drilling holes.
The third option is an antenna-style mount, which uses “U” brackets to mount the light on the hood or trunk edge. No holes are drilled, but screws are used to secure the mount to the edge. SoundOff also makes a dual U bracket, which allows two lights side by side. The lights may also be synchronized. This allows sets of GHOST lights to flash with the same pattern.
Why the external mount? “Optically, the signal is brighter if the light does not have to pass through the angled and/or tinted windshield or rear window glass,” said Phil VonTom, director of Business Development and International Sales. All windshields are tinted, and some are heavily tinted at the top where LEDs are mounted to the headliner, rear-view mirror or sun visor. Finally, LEDs mounted in front of the glass don’t produce the flash back reflection from glass.
To properly direct the LED output from its mounted location, the light itself can be adjusted up or down a total of 30 degrees. The GHOST produces its maximum light output in a band 80 degrees wide and 20 degrees tall. The weather-sealed GHOST has the same climate resistance as any outdoor automotive product, i.e., the same as any external lightbar. The GHOST also has a narrow width. Front to back, including the mounting bracket, it measures just 1.8 inches.
The GHOST may be mounted for a forward or rearward signal, of course. However, it may also be mounted at an angle for an intersection signal, instead of using an outside mirror light. It can also be mounted for a side signal. With the flat and broad pattern of light output from the GHOST, it is intended to be mounted horizontally. The GHOST may be used as an inside B-pillar light where it will be the most effective if mounted on the rear door panel. If mounted vertically on the B-pillar, the visual signal to the side will be very narrow. Mounted horizontally, the visual warning will be quite wide.
The GHOST was originally developed for the volunteers in emergency services. The concept was for very low-profile, very inconspicuous lights when turned off. The goal was for no drill holes while mounting on personal vehicles. The concept was quickly expanded to include any and all unmarked emergency vehicles. UnderCover LED Insert
The last strobe or halogen emergency light application to be replaced by LEDs is the corner strobe. White LEDs have finally replaced halogen bulbs in the take-downs and alleys integrated into lightbars. And now they have replaced the strobe inserts used in the headlight and taillight lenses for corner lights.
The new SoundOff UnderCover LED Insert has exactly the same “footprint” as a standard strobe insert. The upfit is almost exactly the same, starting with a 1-inch hole saw and two drilled screw holes.
Gone is the heat from the strobe tube, which is intense enough to melt headlight lenses and blister aluminum reflectors. Gone is the strobe power supply. Instead of a strobe power supply, these SoundOff corner inserts are wired to a flasher unit. The connectors are very different from those used on strobes to prevent these LED corner inserts from being plugged into a strobe power supply by mistake. The real news is that the intersection warning signal from the UnderCover LED Insert is brighter and more effective than the strobe pulse.
SoundOff faced three challenges in developing a better light than strobe for intersection warning. First was finding an LED emitter that is bright enough. Second, and somewhat related, was getting rid of the heat from the LED, which in turn allows more light output. Third was properly dispersing and directing the light toward the intersection.
SoundOff started with the amount of light needed for this warning and worked backwards. How bright and attention-getting is the strobe corner light? How many LEDs, or how much LED output, would be needed to equal or exceed that? SoundOff settled on the OSRAM O-Star. Somewhat like a 6 LED cluster, the O-Star is actually 6 of the actual chips (die) together to form one emitter. It is 6 die under one optic. In a cluster like this, the whole is more than the sum of the parts. A 1 die produces about 100 lumens. With the same current input, the 6-die O-Star produces 800 to 1,000 lumens.
LEDs get brighter when more current is added and the die surface gets hotter. A strict limit exists on how hot the LED can get and still have the warranty-based hours of service. If the company building the light product can figure out how to keep the LED cooler during use, it can add more current and get even more light output.
“The better heat management, the more light output,” said Mike Walma, SoundOff’s senior product development engineer. The brightness of the UnderCover LED Insert comes both from the use of the 6-die OSRAM O-Star LED and from the extra current added because the product transfers the heat so well.
All this talk of heat from the high-output LED needs to be put in perspective. All LEDs are MUCH cooler than any strobe. In one controlled test, a strobe tube ran 300 deg F, while these LED inserts with more brightness ran 175 deg F. Put another way, these SoundOff LEDs run just 40 deg F hotter than the ambient temperature. And that is not going to melt a headlight housing or blister an aluminum reflector.
Heat-piping™ is the term SoundOff engineers use for the way they transfer heat away from the 6-die surface, down the length of the insert, out the bottom of the insert, and outside the enclosed headlight lens into open air. To do this, SoundOff used the same basic technology that Intel uses on its computer chips to transfer heat.
A long copper plate extends from the 6-die surface down the entire insert to form a large diameter base, which is outside the headlight housing. This is the heat-pipe that transfers heat out of the housing. The copper plate is also attached to a finned aluminum insert housing. Heat transfers from the copper to the aluminum and then to the surrounding air.
Enough total light from one location, emitted through one optic, is a major design feat. And it gives SoundOff great flexibility in how to disperse and direct the light. Other LED corner light inserts are starting to come on the market, but the UnderCover LED Insert is the first to use a secondary optic to direct the LED light output.
With LEDs, the challenge has always been how to properly disperse the light. Fresnel lenses have been the most common approach. SoundOff has taken light dispersal to the next level. Actually, the company has taken this back to its origin. French physicist Augustin-Jean Fresnel originally developed a thin, multi-faceted lens for use in lighthouses. This lens is full of angular prisms arrayed in a dome shape. This design of lens not only catches all the light emitted from the light source, but because it is thinner than a convex lens of equal power, it passes more light.
The optic on the SoundOff LED insert follows the classic Fresnel design. Rings of prisms above and below bend the light into a narrow beam, and the center is shaped like a magnifying glass, so the concentrated beam is even more powerful. The end result of the lighthouse-style Fresnel lens in front of the OSRAM O-Star LED is a bright and flat band of light. The output is 160 degrees wide and 20 degrees tall, a light output angle perfectly tuned for an intersection warning.
Unlike the simple strobe insert, it is absolutely critical that the UnderCover LED Insert, like most LED inserts, be mounted in the corner light housing facing the correct direction! With a strobe insert, you just drill a 1-inch hole and screw the insert in place. It produces light in 360 degrees, so some goes directly out the front and some goes to the back and is reflected out the front.
The UnderCover LED Insert is very different. It produces light in a 160-degree wide band, which is 20 degrees tall. SoundOff provides a mounting template, which clearly shows the direction to face the LED insert. These directions MUST be followed. It is possible to install the UnderCover LED Insert with the optic facing the headlight housing reflector. While that will reflect light forward, it will not be the flat and broad band of light produced by the correctly oriented LED insert.
Most fleet managers know to judge the brightness of an LED 1) at the level the light is directed, 2) at the distance the light is intended to warn, and 3) after the LED has operated for enough time to get as hot (internally) as it is going to get. (Some LEDs wash out in color as they get hot.)
This protocol holds true for the new SoundOff UnderCover LED Insert. Don’t stand next to the vehicle to judge the effectiveness of ANY corner light warning. Stand 100 feet away as if you were a motorist approaching the intersection. Now you can realistically compare “this” to “that” to see which warning signal is brighter and more effective.
The UnderCover LED Insert is brighter than the old strobe insert, especially in daylight. Judge for yourself how it compares to other LED inserts on the market. The SoundOff LED for corner lights is currently available only in white. The colors of red, blue and amber are options for the future.