I tried the quick link and got the same message, even when already logged on to PayPal. I then clicked on Ben's webpage link, clicked on the "Donate Now", and just copied Paul's PayPal link from there, then pasted it into the PayPal "send money" page I already had up (Just ordered my t-shirt!). Seemed to work okay then...
I'm guessing the easiest way would be just to put Paul's (email or eBay ID) name on the Mosfet page. It's Mosfetational!!!
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The brake pedal is my enemy. The brake pedal is my enemy. The brake pedal...
Yup, the button link on Ben's blog page worked for me. I just adopted one.
I've decided to name mine "Little Miss Mosfet":
Little Miss Mosfet
Sat on a circuit
Doing what Paul did say.
Then along came a V spike!
Which, no, she did did not like.
Her smoke got out and blew away!
Thank you everyone! There are now about 2.2 out of 10 mosfets sponsored! I'm going to learn as much as I can about how not to make these cheap ones fail so I don't leave a man behind!
Update: I'm hooking up the Hall Effect current sensor, even though it did get pretty dang hot on an earlier soldering attempt. Assuming it isn't barbecued, I will get a good idea about how much current each mosfet can handle. I'll program it to limit current to 5 and then 10, 15, 20, etc... until it dies???? hmm... that seems a bit harsh. I'll do something similar on the car's version, even though Ian's results with those 200v mosfets says they can handle about 50 amps continuous. It would be good to know for sure in my case, I guess.
I thought I cooked the current sensor, but it still works! Bam! The specs say you can store the dang thing at 180 degC! That should have been a clue that it's sort of big, bad, and feisty!
So, With the single mosfet, I powered the bike with limiting the current to 10 amps, and it seemed slower than with no current limiting, so then I changed it to limit the current to 1 amp, and the little wheel would barely turn! haha! The brakes were rubbing against the rim, so that stopped the poor little 1 amp from doing it's duty! haha! Current limiting is very empowering!
I like the current limiting! and it likes me back!
Plus, the switches are super clean and good and easy to use! Sort of sloppy still, but it's all good. The switch on the left is for the pre-charge resistor. The middle switch is for turning on the controller. The right switch is like the contactor in a car when you turn the key.
There's also a picture of the ATMega8 micro-controller being programmed IN SYSTEM!!! No more unplugging it! ya! I need to clean up the interface for the in system programming, hehehe... but whatever, Back off, you red-headed stepchild!
I rewrote the whole micro-controller program to clean things up a bit. Then I tested the single 100v mosfet controller at 12v, 24v, 36v, 48v, and 60v. It worked perfectly! I set the current limit to 5 amps. When I slowed the wheel down with my hand, you could hear the 4kHz tone get quieter as the current limiting was kicking in and automatically cutting back on the throttle. I would have tested it at 72v, but I ran out of those wire connector things that you can see in the picture, so I couldn't hook up the 6th battery! Oh, that makes me real mad inside!
I'm amazed at how low the amps can be at high voltage to still get excellent performance. It's also amazing that all that power is going through a single mosfet!
I attached the current version of the software, heavily commented.
I was thinking for a kit, buying the stuff in bulk would cut like $50-$100 off the $350 pricetag. I wonder if that will be possible.
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Last edited by MPaulHolmes; 01-04-2009 at 09:46 PM..
Reason: Added software attachment
I Then I tested the single 100v mosfet controller at 12v, 24v, 36v, 48v, and 60v. It worked perfectly! I set the current limit to 5 amps.
I'm amazed at how low the amps can be at high voltage to still get excellent performance. It's also amazing that all that power is going through a single mosfet!
Ooooh, Ooooh, Pick Me!!! No, Wait... I mean, you gotta try something!!! This is the perfect time to do some research on something I've been hearing about, but haven't seen any real proof yet.
Could you try running the bike wheel at different voltages, but with the same WATTAGE? I hear that amperage is preferred over voltage, and vice versa, but just realized that you could find out what kind of power the wheel has at the different voltages if the wattage is the same. You know, like 12v/10 amps vs. 24v/5 amps and so on up to 60v/2 amps. These would all be 120 watts. I would REALLY be interested!
This might not prove anything but how that particular kind of motor works, but it would still be neat to know!!!
