Paul & Sabrina's cheap DIY 144v motor controller

[brihoo2k]

I'm sorry that I haven't posted this before but Ive used this site alot and its a great search engine for finding the availability and best prices on electronic componentsFindChips.com Search the closer it gets to being complete the more exciting it is thank you Paul for sharing the schematic and Motor Control for red lining it. I'm going to get a bread board from the college that I studied programmable logistic control (PLC's) and the components for the control portion hook it up to the scope that I'm waiting on from ebay and try things out. If for any reason I would make any changes to the design I would be obliged to post them while giving full credit to Paul for the original design and the inspiration.

[MPaulHolmes]

I forgot, another thing that has to be changed is right now, it's set up for a 600 amp hardware current limit, which is fine as long as you change it to 12 mosfets, and 12 diodes, since they can handle 50 amps each. You will have to fake the signal from the current sensor, unless you have a 600 amp current source. hehe. 2.5v means the sensor is measuring 0 amps. 3.25v means the sensor is measuring 600 amps. (and stuff inbetween means current inbetween)


PLus, I just heard from Digikey that the other 19 mosfets have been shipped, over a month earlier than expected! ya!

Thank you, Motor_Control! Noise protection is something that I forgot to add in the schematic, and plus I had a few resistors here and there missing that you filled in. Also, I didn't think about making sure the RESET stays high. Good idea!

Brihoo2k, I'll post the micro-controller software once it's done.

This is a lot of circuit to test all at once. Maybe it could be broken into smaller black boxes, and figure out what the inputs and outputs should be, and test it that way.

[esoneson]

Paul,
If you use the HASS 600-S Current Sensor and change to use 12 mosfets and 12 diodes for a maximum 600 amp system, are there any other changes necessary in order to support that high of a current? (Like number of capacitors?)
Remember, I'm just a software guy looking at a strange set of schematic symbols.

Eric

[brihoo2k]

Bummer I went to my previous college today to pick up a breadboard because I know they had ginormous ones which would be better that a small ratshack special but they no longer sell the breadboards alone and have a kit in a box.They were not going to open the box and I didnt want them to but if it didnt have anthing on the box saying what the contents were I wasnt going to persue it. I have some pcbs, some really light thin ones that would be ok for the control part but I want to make sure everything works before doing any etching. I just think its a good idea to have a mother/daughter board between the control and the major power going through the mosfets and the diodes. Then I finally got an e-mail from the person I bought the tektronix 2213 60mhz oscilloscope off of. I paid for it on the 10th and they just now sent it on the 17th.

[MPaulHolmes]

Originally Posted by esonson

Paul,
If you use the HASS 600-S Current Sensor and change to use 12 mosfets and 12 diodes for a maximum 600 amp system, are there any other changes necessary in order to support that high of a current? (Like number of capacitors?)
Remember, I'm just a software guy looking at a strange set of schematic symbols.
Eric

You can actually use the HASS 300-S up to the HASS 600-S sensor. The 300, 400, 500, and 600 all can safely measure up to 900 amps! haha! I ordered the HASS 500-S, but it would be better to get the 300 version, because it would give a bit more voltage resolution when it measures all the way up to 600 amps.

Check out Page one of the HASS documentation:
HASS! YA!


24 of those 200v 470 uF ripple capacitors is still plenty. To give you an idea, the Kelly 144v 600amp controller uses 10 330uF ripple caps. I was reading on the DIYElectricCar Forum about a guy that took one apart.

So, to sum up, just change to 12 freewheel diodes and 12 mosfets, and it's a 144v 600 amp controller. Now, it would be better to have 2 mosfet drivers (driving 6 mosfets each). Maybe I should change it to account for that.

brihoo2k: That's a good idea. I would definitely breadboard this thing first. There is way too much that can go wrong with such a big circuit. We need to break this thing up into several parts, and test each part.

[bennelson]

Originally Posted by MPaulHolmes

To give you an idea, the Kelly 144v 600amp controller uses 10 330uF ripple caps. I was reading on the DIYElectricCar Forum about a guy that took one apart.

The only guy I know personally who has used a Kelly controller could NOT say anything good about it. He had nothing but problems with it.

Just saying that a Kelly MIGHT not be the best to base your own design on.

[MPaulHolmes]

That's right Ben! As a less ghetto example, the Curtis 144v 500 amp controller has 35 200v 220 uF, and we'll have the equivalent of 48 200v 235 uF caps. Plus, these caps have the highest ripple current capability of any of comparable size. That engineer's conclusion was that the Kelly 144v controller was more like a 96v controller.

PS: Remember I was saying those ATMega8's are cheap? Here's a good example of what I mean...

Cheap ATMega8's!

I'm going to see of they combine shipping. 50 cents each is a good price. hehe.

[motor_control]

Originally Posted by MPaulHolmes

it would be better to have 2 mosfet drivers (driving 6 mosfets each). Maybe I should change it to account for that.

2 mosfet driver's outputs need to be connected together.
May be with two resistor by 0.33 ohm.

[motor_control]

Originally Posted by MPaulHolmes

Check out Page one of the HASS documentation:
HASS! YA!

I've DOUBLE checked it out !

And plot new sch for 600 A triggering. Using Vref of LEM HASS is more accurate INHO.

[motor_control]

I think that the first test you must doing with current limiting about 200 A - R2 obout 22 k

==========
Int Vref ATmega8 is low acurate:

VINT Internal Voltage Reference 2.3-2.7 V and typ. 2.56 V
Table 103. "ADC Characteristics"

I recomend to use external one, from LEM HASS module - Vref 2.5 ± 0.025 V

That is how.



For lowering voltage for ref 2.5 V ch. ADC0 and ADC1 must be shunted to GND pin 22 mega8 by 100 k resistors reffer my sch modes in page 20.