Recent content by lawsonuw

Would any one be interested in a schematic an analog front end to do high precision battery cycling like in this video? I've been using some parts at work that should be able to get close to the precision in the video for about $100 channel + assembly. Don't have time to do the software for it...

Little late to this party, but I have a few suggestions regarding suspension geometry/setup. First http://www.tonyfoale.com/ has a ton of info about motorcycle setup and unconventional front suspensions in particular. http://www.tonyfoale.com/Articles/Dive/DIVE.htm Is the core of the info...

The cheap brushed hub motor I tired was about the same as always riding on a nearly flat tire. I'd expect a brushless hub to be more line an underinflated tire, and a geared hub with freewheel to be nearly imperceptible. Unfortunately the weight is more of a problem with hub motors. High...

I chose a through the gears drive for two main reasons. I wanted the drive system to be light enough that I could still pedal the bike easily, and I wanted enough torque to winch me up steep hills. (there was also a fair component of seeing if the crazy plan would actually work) I don't...

Of course there's always the "ghetto" method. A stack of four 74AC14 (Maybe a 74AC240 octal buffer?) with all the outputs ganged should net 1 amp of output drive, a max supply of 6volts and switching frequencies in the megahertz. (use a stack of more 74HCxx chips if a higher supply voltage is...

Personally I'd invest in some "lab equipment" and just BUY a simple H-bridge board for the initial testing. The following two sparkfun.com boards look about right. http://www.sparkfun.com/commerce/product_info.php?products_id=8902 or...

Yes the SPICE program will show a wave form after the inductor. The wave form will only be as accurate as your simulation. I.e. all components in a SPICE model are ideal. Parasitic components of the circuit need to be added manually if they're important. (or added via component sub models)...

My thought on a half-bridge driver would be to use an integrated Half-bridge chip. Infineon makes many different versions for automotive applications. Digikey TDA21201-P7IN-ND also looks interesting and is in stock at Digikey. I like the simplified schematic you've posted. I'd personally...

http://www.sparkfun.com/commerce/tutorials.php Read the "surface mount soldering tutorials" Tweezers, solder wick, and soldering iron make short work of SMD assembly. (dis-assembly, not so much) 12xx series SMD passives are fairly big. (like 3mm long and ~1.5mm wide) If you find something...

I don't think all the DC isolation capacitors need to have the same voltage ratings. Specifically, I think the caps only need to be rated for the DC voltage they block plus some margin. So the first two cells would be fine with 10v caps, the next three could use 25v caps, the next 5 cells...

With the "tire" that you put on the motor walking over to one side, it sounds like the motor and wheel are slightly misaligned. My other suggestion would be to use a high quality superglue to glue the tire on. I used super glue to fix RC car tires to rims and it holds quite well...

This exactly matches the conclusions I reached from my half-arsed experiments. I.e. LOTS of power, a small battery, minimal weight, and no drag makes one heck of a fun "turbo" button! (5-10min of turbo ai'n't bad either) This also works very well with the human engine. If you look at of of...

Or a higher resolution commutation sensor and two commutation look up tables. One for Wye and one for Delta. Lawson

Got tired of walking over a massive icy plow pile several winters ago. (smashed the local snow fall records that year) Broke out my trusty flat blade metal shovel and chipped cut through the hill. Left on Christmas break a day or two later. The best of all this is when I returned, the...

I'd not be too surprised if this was an "eccentric ratchet" (my own name) CVT combined with a planetary gear set to give it zero speed capability. (i.e. to subtract the input rpm from the CVT's output rpm) An additional output gear would then be used to get any desired top speed input:output...