Responder PSE's Blog

This is an article we sent out in our last email newsletter because we get this question quite frequently…

Light Emitting Diodes, those magical illuminating semiconductors, have been around now for more than four decades. In just the last ten years or so, the led has undergone a tremendous evolutionary transformation. Originally only able to produce light in the red wavelength, they can now produce nearly any color in the spectrum. In addition, the achievable power levels of leds have increased exponentially. This has led to explosive growth in the emergency vehicle lighting (EVL) market.

The term “Gen1” generally refers to the traditional 5mm led which has been with us for most of the last forty years. The 5mm led typically has a light dispersion angle of approximately 10-15° but the overall light energy is relatively low. Because 5mm diodes were the only affordable option when emergency vehicle lighting began to incorporate them almost ten years ago, generating enough light to meet emergency vehicle lighting standards required using large number of these Gen1 leds to do so. This is why Gen1 products are made up of tens, if not hundreds of leds. Products based on the Gen1 led are economical to produce and therefore provide an affordable entry level option. However, it’s important to understand the inherent limitations of these lights. They have a very narrow angle of visibility and they tend to lose their effectiveness in bright sunshine.

The Gen2 led, also known as the Super Flux led, is widely used in automotive applications due to its higher energy output, much wider viewing angle and stout architecture. However, it did not find its way into many emergency vehicle lighting products. This can be attributed to both its size as well as the need to group large numbers of these leds together to produce a significant light output. Currently there are very few products using Gen 2 LEDs.

Today’s high tech leds come in a wide range of configurations. It’s no longer an apples to apples comparison. The reference to Gen3 is more akin to the fact that these new leds are able to operate at much higher energy levels for longer periods of time. This translates into a significant increase in light output. So it only takes a few of these high output leds to provide the required light output required for EVL. In addition, these leds have very wide viewing angles, in some cases as much as 160 degrees. Because of this, products utilizing these leds have a greater effective warning signal. The Gen3 moniker therefore, is a misnomer. A much more accurate classification of these leds is wattage. leds used in most EVL products are either 1w or 3w. Higher power levels have been developed, but the heat they generate is greater than can be effectively dissipated. This means that for the foreseeable future, this is where “Gen3” warning lights will remain.

What does all of this mean? In short, Gen1 products offer generally acceptable performance at an economical price point. Products such as the Hawk I and Hawk II provide an economical entry point for the first responder. Gen3 led products are the current industry standard. These products offer the greatest performance in light output and wide angle visibility. Dash lights, such as the Titan series, and grille lights, such as the TLED04 and RECT-14 are brilliant day or night. They provide the greatest level of visibility and when you get down to the heart of the matter, being seen is the key to being safe when responding. Conspicuity is the key and emergency vehicle lighting incorporating Gen3 leds are the best performer.