With a lot of practice about working with vinyl in my back, building the box for the electronics was not such a big task anymore. I started with cutting out the different parts, then I glued some of them together, and I screwed some others.

Here you can see already the almost finished case.

I've built those parts to mount the box on the wheelchair chassis.

That's a close up of the side, which will hold the box, later.

This is a first test of mounting the box at the wheelchair.

Then I started to build the stuff inside that box. While the boards already existed, I had to build a new power supply. The old one would have been too big for that box. The purpose of this part is to get the different voltages, that the electronics require. The batteries only supply 24V, but some parts of the electronics work with 12V and most parts need 5V. So the small devices screwed on the black aluminum heat sinks are voltage regulators. They provide 12V and 5V and transform the voltage difference to heat.

This is the setup with the two drivecontrol boards and with the power supply inside the electronic box. You can also see the 2mm copper shield which serves as electrostatic shield. Of course, that sheet has to be connected to GND for that purpose.

Inside that box, there is enough space for more boards, which can be set on top of the drivecontrol boards. The board on the left already contains two fuses for the 12V and 5V circuit and for the power distribution. I will use the rest of the space on that board for the entertainment controller. On top of the right board, I will place the mp3 player.

For testing the system, I still used my old service control unit. The final service control unit is on the back side of the service latch, which you could already see in the test drive video #4. Through that service latch, I have also access to the programming and debugging connector and to the compact flash card of the mp3-player.

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