RobotBuilder

E15 Elec-trak

Elec-trak Mowing at River

Painting, Putting Together, and Wiring

The First Elec-trak Electronics

The first electronics design is pretty much the same electronics running in the Elec-trak now with but the HIP2101 Half-bridge driver for the mosfets didn't last long. The original design worked excellent during testing but only drove the tractor for about 10 feet before the FETs became Fire Emitting Transistors. This is because the chip didn't have any built in protection against the FETs turning the high and low side on.

The board was hacked in the end having a little board with a LT1162 full-bridge driver. I only hooked up half of it for the armature and the electronics worked great for the entire winter of 2003/2004. It plowed after many snow storms and had no problems with the electronics.

Revision 2 Electronics

After having success with the my original electronics design and the new LT1162 chip, I decided it was time to make a final version for the board since I didn't like having mosfet drivers off to the side. I figured it would be unreliable in the future. So the new board had used the LT1162 chip with both half-bridges used and again this time the tractor only ran about 30 seconds before the smoke came out...

I spent a lot of time figuring out what went wrong and being confident that I had everything hooked up properly. Eventually I called tech support at Linear Technologies and emailed my schematic to them. They said they couldn't see anything wrong with it and would try building it themselves. Their conclusion was the chip needed to dissipate over 1 W of power and juction temperature would reach 100 degrees Celcius. Then it would fail...

I don't have final pictures of this board but this board is still running in the E15 now with an attachment board containing IR2184 mosfet drivers.