Paul & Sabrina's cheap DIY 144v motor controller

[squiggles]

I was just glancing over the schematic and noticed that pins 4 & 5 of J1 have the same net name, my PCB cad package would tie them together. Hope that is not an issue with yours.

[charlie_fd]

Originally Posted by MazdaMatt

quick googling turned up nothing... are the atmel users just not interested in interrupt driven communication? Every uart code snippet I saw had a while(blah blah){sit here with your thumb up your...}
....

FUNCTION Main
  Enable Global Interrupts

  LOOP FOREVER
    {Do Stuff}
    Transmit_Data(Data)
    Sleep
  END LOOP
END FUNCTION

FUNCTION Transmit_Data(Data)
  Store Data into RingBuffer
  Enable TX Buffer Empty Interrupt (instead of Dean's TX Complete Interrupt)
END FUNCTION

ISR TX_BUFFER_EMPTY_ISR
  IF RingBuffer NOT EMPTY
    UDR = RingBuffer.Next
  ELSE
    Disable TX Buffer Empty Interrupt
  END IF
END ISR

More about that, including a link to a ringbuffer implementation fond in the same place as the (pseudo)code above: View topic - [TUT] [SOFT] Using the USART - Interrupt driven serial comms :: AVR Freaks

[MazdaMatt]

Thanks, Charlie. It is pretty easy when you aren't going to be receiving and you aren't using any kind of proper data encapsulation.

[MPaulHolmes]

An update from our friendly neighborhood engineer...



Installed all connectors and the input components only (see pic). Here is where I start to test:
-Reverse polarity protection
-Overvoltage clamping @19V
-Common mode filtering of noisy +12V input (I'll attach a +12V brushed motor in parallel with input to verify spikes don't get through)

[esoneson]

Beauty....beauty.....beauty!!

A long way from a radio skank bread board.

Thanks for the progress report. It does a body good.

Eric

[vinny1989]

For a "cheap motor controller" Its looking great.

Just curious, but what is the minimum voltage this controller would be able to run / control a car at?

[MPaulHolmes]

The minimum voltage that you can give the controller for driving the car is 0, and the maximum is about 150v. At 0 volts, your top speed will be pretty low. hehe. But the controller would be perfectly happy with, say, a AA 1.5v battery as the power source for the motor. That's the beauty of powering the controller with the 12v auxiliary battery (but using an isolated DC-DC converter inside the controller). Absolute flexibility with the pack voltage! ya! And if someone uses 600v IGBTs, diodes and caps? Then the allowable battery pack voltage would be 0 to about 550v or so. Otmar, the Zilla maker, suggested to me that isolated DC-DC that we're using.

[MPaulHolmes]

As for cheap motor controller Oh, ya... I believe in bulk, that those control boards would cost around $8 each! ya! 2 Radio Skank boards (hehe, that was really funny Eric) cost $8!

I just bought the aluminum plate for the base of the controllers. It will be shipped here in a few days, then I'll drill the appropriate holes in it. The plate is 3/8"x7.875"x38.375", so I can hack that up to whatever it needs to be. That will be a nice solid base, and a pretty dang good heatsink too. So, Hondo, could you make those enclosures so that the fins stick out so that the total width of the enclosure is around 7.875" wide or so? hehe. I only need to really settle on the internal height and length now. It will be around 3.5" high or so inside I'm thinking, and maybe 10.5" long ERRRRRRR SOooooo! I really need to figure that out! I wasn't sure how tall the control board would end up being, but now I have an idea of that. I am so sorry that I've slacked in that department! I'm such a internal dimensions slacker!

[NiHaoMike]

For the power stage, what about oil cool it? Put it in a sealed container, seal up the power and control lines, connect a cooling system with a pump and transmission cooler, and fill it with transformer oil. Something like one of those speciality PC power supplies. JonnyGURU.com - Power Supply Reviews and more! - Reviews - Koolance PSU-1200ATX-12S Liquid Cooled 1200W power supply

[nubie]

Originally Posted by MPaulHolmes

An update from our friendly neighborhood engineer...

[IMG] http://i419.photobucket.com/albums/p...components.jpg

Installed all connectors and the input components only (see pic).

I love it!