Out of all the things to build this one is the most challenging for me. I have very little experience with building electronics. So I did what everyone in my situation would do and watch all the you tube on this subject. (to youtube's credit, there is lots of good content). I set out to design a brushed ESC that can handle the following power:
- 30A Continuous
- 24V max voltage
- Current sensing
- Temperature sensing
- Arduino bootloader
- Power output for case fan
- Header for users to expand upon if they want to
So with all those things on my design list, I set out to design version 1.0 of this controller. At first I used the VNH2SP30-E-1. This is a real nice chip because it dose quite a bit of the hard work for you since it is an all in one package (current sense, over temp shut off etc.). BUT when I went to buy the chip it had said that it was being discontinued.... So I switched to the VNH5019A-E. This chip is basically the same thing except it handles higher voltages and is not being discontinued. Below is a srceen shot of the final board design:
With all of the design criteria met, I sent the Gerber files to the board manufacture and ordered all the components.
Soldering the board was real easy because I made an Arduino controlled toaster oven to reflow the solder. My first board went well except for the fact that I oriented the micro controller the wrong way and the pins for the motor controller chip had some shorts in it because I did not position it close enough. So I then proceed to make another board to correct all my mistakes. With a now freshly solderd board, I flashed the arduino boot loader (real impressed that it worked first shot) and then procedded to connect the battery..... The smoke came out of the board.... I put the leads on reverse polarity. this forced me to go back to the spread sheet of the chip and then I found some other design problems that could let the smoke out. I then assembled a third (3) board this time I will power it up with a power supply (ordered it last week) as to limit the current. I also bypassed the reverse polarity mosfet as it does not do anyting right now AND it may cause another unforseen problem. So whenever I get the power supply I will contunue to trouble shoot the board. Here is a picture of the latest board build complete with bypass wire instead of a mosfet.