Impart Special Products (a division of Inventis Technology) is a long established Australian vehicle control systems designer and manufacturer that specialises in embedded control systems as well as safety enhancement solutions for a range of applications.
It has been a long time supplier of controls and speciality accessories such as vehicle siren and PA systems, work area lighting and light controllers and safety enhancement systems to police, fire, ambulance and emergency services fleet owners and body builders for more than two decades. Innovative CAN-Bus control solutions are already helping body builders reduce installation costs, add features and improve safety.
The latest development focuses on ensuring compliant operation of LED blinkers, in line with the requirements of the Australian Design Rule ADR 13/00 which relates to the installation of lighting and light signalling devices.
Impart Special Products asserts that the paragraph of most interest is paragraph 6.5.8. ‘Tell-tales’, which relates to how a tell tale system in a vehicle (typically a flasher indicator) will notify an operator if an indicator globe fails.
Put simply, in the event that a vehicle indicator fails, there must be a visual and/or audible warning that the indicator has failed. In most vehicles, if a globe fails, the indicator flashes more quickly. This is usually both a visual and audible warning.
If you install LED taillights on vehicles designed for traditional incandescent globes, the result will be that the indicator flasher unit will flash faster, as though there was a fault because LED lights drawn less current and the indicator circuit assumes this is the result of a blown globe.
To overcome this when replacing globes with LED light fittings, there were previously only two options.
The first is to ‘hot wire’ the tail lights with a resistor that applies an additional electrical load, as though there were a globe rather than an LED light. If the LED light then fails, the system will have no way of detecting that there is a real fault as the resistor fools the system. This option is in breach of the Australian Design Rule.
The second option complies with ADR 13/00, but is complicated and can be expensive. It involves rewiring the vehicle with a dedicated wiring loom and electronics, designed explicitly to accommodate LED tail lights by simulating the correct load while monitoring the LED light load and simulating a change in load if the LED globe fails. This may require the use of a specific brand of LED light to match the vendor’s wiring system and can make ongoing vehicle maintenance problematic, especially with respect to field repairs.
While Australian road authorities will not defect a vehicle for incorrect installation procedures, they can defect drivers for having non-functioning turn indicators. The simple fact that inappropriate installation techniques can prevent drivers from realising their vehicle has a faulty turn signal makes this issue of concern.
Impart Special Products has developed a device that is cheaper, easier to install and approved to ADR 13/00. The Blinker Load Simulator (BLS) is a simple low cost accessory fitted into the indicator circuit that simulates the load of a globe, but is smart enough to recognise an actual fault and report this to the indicator system inside the driver cabin.
It is typically installed near the rear indicator light and mimics the electrical load of a globe while looking at the load from the LED itself to determine that the LED is still functioning. The BLS fools the vehicle’s electrical system into thinking a globe is still installed, but will report a fault to the vehicle system if the LED fails.
What sets it apart is that it can be easily installed with a pair of pliers, a screwdriver and a crimp tool; and the trip load can be set via user selectable dip switches. Selectable loads are 30mA, 150mA and 300mA. Installers should check their vehicle service manual to determine the required trip amperage for the indicator/blinker circuit.
The BLS is available in two models, one for 12v and one for 24V vehicle systems. The unit is weatherproof and comes with a wire tail comprising of three one metre leads that are simply cut to length, fitted with crimp connectors and fitted into the indicator circuit.
The unit itself is compact, measuring 110mm wide x 60mm high x 30mm diameter (or 140mm wide including the mounting flanges). It can be mounted in a suitable position under the vehicle chassis, or under a cargo tray using four screws. Impart recommends that it be attached to a metal substrate (eg. the vehicle chassis) to dissipate heat. For user safety, the unit should be mounted where it can’t be easily touched during normal activity around the rear of a vehicle.