Design and production of embedded electronics, software, telemetry- and remote-control applications


Embedded electronics

On of the main target areas for Novatron AS is design and delivery of embedded elctronics, special electronics designed for executing a specific function. This may be anything from simple analog interfaces, via power electronics to advanced microprocessor-based control-modules with complex software. Often, this also includes complete solutions including special designed mechanical enclosures where the elctronics itself is just a part of the complete product. The primary target is that the electronics and mechanics together shall form a customized unit that fits with the given product specification.

The remote control panel for Minecat demining machines is a typical example of customized embedded elctronics

The example above is a relatively complex module which contains both wireless communication, displays and different control devices such as 1- and 2-axis joysticks, knobs and pushbuttons. In addition comes battery-packs with large capacity for the long range radios, customized charge regulators and battery supervision circuits. The software packet contains interfaces for all control devices, displays, radios, lamps and acoustic alarms. In addition there are test menues for local test of panel functionality and retransmission routines to ensure safe communication. Safety functions such as emergency stop button and "dead man" timeout functionality is a natural part of such remote control system. As this equipment is designed primarily for use under hot, partly desert conditions, special considerations had to be taken regarding temeperature and dust.

Other examples: Microprocessorbased control board and license-free 433MHz ISM-band radio-link with USB

An other example of an embedded electronics module is shown below. This is a solid state (all electronic) relay developed for use on the same machine as the panel above. The demining machines was equipped with 2 diesel engines that both needed high currents for glow-plugs and for the starter solenoid. The glow-plugs could draw up to 100A from cold condition and this demanded thick cables and heavy contacts on connections leading to these devices. To minimize cable connections and cable thickness and at the same time ensure optimal voltage for the plugs and starter solenoid under cold conditions, we developed a small solid state relay that was maintenance free and that could be fitted locally on each of the engines and that could be supplied with current directly from the high cross section supply cables going from the battery to the starter engines.. From the relay, short, moderate size cables, connected directly to the glow-plugs and the starter-solenoid, something that minimized voltage loss. The connection to the central control system was now limited to 4 thin cables, 2 control signals and 2 status signals, connected through a low current (4A) connector.

The solid state relays had electronic current limiting on 70A for the starter solenoid and 130A for the glow-plugs. In case of short curcuits, the electronic overload protection would go into action and switch off the affected output and signal the error situation back to the control system. As a respones to the error situation reported, the operator could try to repeat the operation in case there was as transient situation, or perform necessary repair if the condition persisted. The electronics was self-protected and was fully operational again without any intervention as soon as the error condition was removed.

2-channel "solid-state" relay for start of diesel engines

The images above show 3 steps during mounting of a solid state relay, type DSR. Image 1 shows the electronics assembled with cables and fitted in the enclosure. Image 2 shows the module after it has been filled with a heat transferring epoxy mass that had a double function. Firstly, it transfer any exess heat from the modules to the enclosure (and to the brackets on which it is fixed) and secondly it fixes all electonic parts and cables inside the enclosure to protect them from mechanical fatigue due to the strong vibrations on the machine. Image 3 shows the final module complete with attached marking labels.

Notice the 3 lamps (light emitting diodes) on the top. The center lamp lights green whenever there is a +12V supply voltage available. The 2 other lamps shows status on each of the 2 relays as a guidance during fault-finding. When a ralay is activated, the lamp goes to yellow. If the output is shut down due to overload, it changes to red to indicated a "fault" condition. This simplified fault-finding.

Below is shown som images of an other special embedde module from the same project. This is the main power distribution for the machine, a module that contains all fuse- and distribution-functions in addition to som high current relay outputs for valves, brakes and cooling fans. Everything is electronically protected against overload and will handle and indicate any fault conditions without permanent damage. The module is epoxy filled to provide cooling and stabilization against vibration in the same way as with the small relay above.

Solid-state relay- and power-distribution unit in different steps of assembly

HKK/10.10.2012