Producing reliable electronics for roadside installations

Director of A.D. Engineering International Peter Harris reveals how the company is focused on producing the most reliable equipment for roadside installations, for the traffic ITS industry.

“Consultation with the people that actually use and service the equipment is essential in developing equipment that is reliable for the long term.”
-Peter Harris

What are the main challenges to producing reliable equipment for the roadside environment?

Peter Harris. A.D. Engineering International (ADEI) is focussing on producing the most reliable equipment for the Intelligent Transport Systems market, as this appears to be a hole in the market in Australia. There are several key areas that make equipment fail in the field, especially in harsh environments such as by the roadside in Australia, such as keeping the moisture away from electronics and connectors; keeping power transients, surges and dips from getting to the sensitive components; keeping the temperature within acceptable limits; allowance for service "finger poking" (i.e. mechanically robust) and ensuring the equipment actually works by testing, testing, testing.

This is pretty obvious stuff, but is quite difficult to achieve, especially in this environment.

And how do these problems get solved?

PH. Well, without giving away too many secrets, we are designing the equipment, right from the base level, to combat each of these problems.

For example, the enclosures are designed specifically for the equipment they house and are designed to be IP rated, so that no water can enter the cabinet. The door seals are the last step in the weather proofing, rather than the first or only step.

All boards are coated to seal out moisture. All connectors are protected with a special grease and the cabinet is fitted with a vapour phase corrosion inhibitor.

Protection from incoming power spikes, surges, dips, etc. is difficult to protect against. There are a number of devices that are used to filter the power and other techniques. By working with testing labs, we can "harden" the power supplies to survive everything except a direct lightning hit! This ensures the equipment will continue to run for the life of the product without "falling over" due to power issues.

In Australia (and indeed other parts of the world, such as the Middle East) high temperatures are a big problem for roadside equipment. There are several techniques that are employed to combat this issue. The best technique is to design extremely efficient, low power consumption circuits that produce little or no appreciable heat. This way cooling is not generally required (removing the need for fans/filters or even air conditioners). If the enclosure is mounted in full sun then the cabinet colour plays a role in thermal management. In some cases the enclosure may need to be double skinned, or have sun-shades.

By far, the biggest input to the design of the equipment comes from field experience. Seeing the shortcomings of other designs, consultation with the people that actually use and service the equipment is essential in developing equipment that is reliable for the long term.

What is the main aim of ADEI for the immediate future?

PH. Quite simply - to be the best. We intend on being the only supplier of choice in the market place. If you want the best, then ADEI will be supplying it. However, being the best does not necessarily mean being the most expensive. By being innovative in the design process we believe we can produce the best equipment at realistic prices. Part of the reason why this is possible is also to do with our ability to partner with our suppliers to have the same product philosophy.

About

Peter Harris is Director and Engineering Manager of A.D. Engineering International, responsible for the direction of the company and directly involved with product design and improvements, with more than 20 years experience in ITS equipment design and installation.