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Old 08-03-2010, 11:42 PM   #3621 (permalink)
MPaulHolmes
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Join Date: Feb 2008
Location: Maricopa, AZ (sort of. Actually outside of town)
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Michael's Electric Beetle - '71 Volkswagen Superbeetle 500000
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I checked out the LEM current sensor with 3 wraps of wire around it. I measured the current with a 200amp 200mV shunt, and with a Fluke 337. The fluke 337 gives identical results as the shunt! 17amps on the fluke, 17mV across the shunt! They don't mess around at Fluke!

So, since I'm using a LEM 50, with 3 wraps, it should behave like a LEM 16.666666667, which is 50/3 HEHE. So, according to the datasheet, 16.666667 amps on the charger should result in a reading from the LEM of 512 + 128. Know what it was? 512 + 128. Ya. Perfectly accurate. That's what I"m talking about. The Japanese make some good stuff.

So anyway! I'm ordering those 1000amp control boards. Friggen heck ya! Does anyone want to buy one so that I don't go broke in the process? I am praying that there are no mistakes. There probably aren't since much of the circuitry is so similar to the charger I recently made, and that works perfectly. The few minor mistakes that the charger had, I already fixed on the control board layout for the controller. The control boards are going to be around $29 each before tax and shipping (I'm ordering 10), so probably $35 each would cover the cost of them. If I can get like 3 or 4 people, I can afford the rest. The software is actually mostly done, since it's SOOOOO similar to the charger. The same microcontroller. The dsPIC30F4011. All the chips are throughhole, so you can socket them, and all the resistors and capacitors are surface mount. 0805 and 1206 package resistors and capacitors. It's actually easier than through hole soldering once you get used to it. All you need is some solder flux. I can explain how if anyone needs help (or watch youtube video. haha. That's where I learned how).

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