Search found 11982 matches

by fechter
Mar 27, 2007 8:37 am
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

No acetone, it sounds like it will work fine. You can always limit the throttle on the regen. It would be a good idea to think about an interlock that will prevent the regen and main controller from being on at the same time. I think the simplest way would be to tie into the brake lever switch. The ...
by fechter
Mar 26, 2007 8:49 pm
Forum: E-Bike Technical
Topic: Help
Replies: 16
Views: 1860

Sounds like a shorted MOSFET in your controller. Sounds like that to me too. I hate it when that happens. Try disconnecting the motor phase wires (the fat ones) and use an ohmmeter to measure the resistance from each phase wire to both the main red and black battery wires going to the controller (s...
by fechter
Mar 26, 2007 7:40 pm
Forum: E-Bike Technical
Topic: Can you add a regen circuit
Replies: 16
Views: 3915

You're missing something. The idea is the brushed controller briefly shorts out the motor windings, causing the magnetic field to build. When the switch opens, there's a big voltage spike that gets circulated back to the batteries by the body diodes in the main controller FETs. We don't want to diss...
by fechter
Mar 26, 2007 2:36 pm
Forum: E-Bike Technical
Topic: Can you add a regen circuit
Replies: 16
Views: 3915

You could connect the bridge rectifiers directly to the motor all the time and have a single FET or relay switch right before the voltage converter. When the switch is open, there won't be any current in the rectifiers. In my circuit, the cheapo controller acts as a voltage converter, but a properly...
by fechter
Mar 26, 2007 2:10 pm
Forum: E-Bike General Discussion
Topic: Tidial Force owners
Replies: 12
Views: 1975

Welcome miro13car! The TF is a very nicely designed bike. I've only seen pictures, so I don't have much first hand experience. It seem like since the company is belly-up, any battery replacement is going to be a DIY job. The most elegant solution would be to tear apart the existing pack and replace ...
by fechter
Mar 26, 2007 12:20 pm
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

What would happen with this circuit and the bike if: A FET in the brushed regen controller blew (would the driving wheel lockup?) Yes. This could be ugly. It wouldn't exactly lock, the wheel would still move, but slower than the speed of the bike. With a hub motor, this might tend to over torque th...
by fechter
Mar 26, 2007 9:04 am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

Thanks Knoxie. After my 6mi of jackrabbit starts and serious hill climbing, the motor was barely warm. The cool weather really stops heat buildup. When it's 90F outside, it gets pretty warm. My batteries are 13Ah, 48v, used surplus chunks of lead (free). If I go all out, full throttle with lots of h...
by fechter
Mar 26, 2007 8:37 am
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

I don’t understand what this is about, but looks like you guys are on to something interesting here. Really into those special gadgets that generates juice. Not how much juice I can carry rather, how much juice can I produce, is key. Keep it up! If you hit the regen while pedaling,...
by fechter
Mar 26, 2007 8:33 am
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

Q: If I used a 35A / 100V 3 phase bridge rectifier @ 50V, would the rectify-able amperage be 70A? Alternately, if it were a 25A / 200V bridge running @ 100V, could it handle 50A? Am I thinking about this too hard, or not hard enough? (Edit: My monster headache and inability to sleep would indicate ...
by fechter
Mar 25, 2007 9:15 pm
Forum: E-Bike Technical
Topic: Fechter's current based throttle
Replies: 222
Views: 34001

I have all the parts. Coming soon.
by fechter
Mar 25, 2007 9:14 pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

I would have thought most of the noise is the gears no? I did once ride a bike with a brushless motor that actually made no noise i could hear at all, though I was in a busy market place at the time My Vego uses a belt, which is very quiet. When it was running the stock brushed motor, it made a dif...
by fechter
Mar 25, 2007 9:10 pm
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

You could also use two very common single phase full wave bridges and tie them together. Half of one of them would be unused, but they are nicely packaged and have isolated heatsink mountings.
by fechter
Mar 25, 2007 4:21 pm
Forum: E-Bike Technical
Topic: Make: Fechters' Braking Regen Add-on for BLDC Motors
Replies: 133
Views: 16608

I'm glad somebody is going to test the idea. The workmanship on the diode bridge is excellent. Too bad they're only rated for 6A, which means the current limit in the regen controller better be 6A or they might not last long. If you don't give the regen controller much throttle, you can keep the amp...
by fechter
Mar 25, 2007 4:07 pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

Brushed motors are actually quieter usually. Most brushless motors make some noise. A BMC or Kollmorgen are similar. The Crystallyte motors have overlapping windings which will minimize the noise. Some of them have skewed stator poles which helps too. If the controller had a trapezoidal or sine wave...
by fechter
Mar 25, 2007 3:53 pm
Forum: E-Bike Photos & Video
Topic: Deecanios first build the "DC1"
Replies: 723
Views: 84881

6 threads should be enough. When the motor starts torquing the arm, the spot where the welds are will be put in compression, which will help their strength. If the main axle nut is tight enough, the torque arm isn't really carrying any load. It's a good safety in case the nut loosens. If there was e...
by fechter
Mar 25, 2007 2:43 pm
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

I was born and raised in Minnesota, but I don't miss the winters there. I get spoiled by the climate here. It was 79 two days ago, which is much more comfortable for riding. I still hate the wind, which is frequent here. The noise is interesting. My son says it sounds like a muscle car with a roots ...
by fechter
Mar 25, 2007 2:33 pm
Forum: E-Bike Photos & Video
Topic: Deecanios first build the "DC1"
Replies: 723
Views: 84881

Nice progress... You only have a few threads left on the axle bolt, which is not really enough. I would place the arm under the nut that's there and shorten the spacer that goes to the brake mount if there's enough room. I guess I would have gone for attaching the end of the arm to the other brake c...
by fechter
Mar 25, 2007 11:35 am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

Violated!

Anyway, the video was something like 18 minutes. 10 minutes is the maximum allowable. I guess I should have tried the video.google thing. Somehow I thought that since google bought out YouTube, they were the same thing.
by fechter
Mar 25, 2007 12:36 am
Forum: E-Scooter and Motorcycle Photos & Videos
Topic: Video of Fechter's Vego SX-600
Replies: 36
Views: 9409

Video of Fechter's Vego SX-600

Here's the link: http://www.youtube.com/watch?v=9TOJ9PhxqIg My first attempt at a rolling video. I used a foot-long mini tripod that was zip-tied to the shoulder strap on my backpack. It has ball joint under the camera that allows a wide range of adjustment. It puts the camera at about chest level, ...
by fechter
Mar 25, 2007 12:19 am
Forum: E-Bike Technical
Topic: Brake disconnect
Replies: 18
Views: 2759

I'll have to check on that one when I get back to work where my ripped apart controller is. I don't use the brake switches, so I haven't paid any attention to them. As far as I know, the brake switches are normally open, and close when you apply the brake. This shorts the throttle wiper to ground, s...
by fechter
Mar 25, 2007 12:01 am
Forum: E-Bike General Discussion
Topic: New forum member says 'hi'
Replies: 18
Views: 2531

So far, so good. It looks sort of like that thing Knoxie was riding around in the snow with. It looks a fun thing to ride.
With a motor, it will be like a go kart, only legal to ride on the street.

Welcome aboard :D
by fechter
Mar 24, 2007 11:55 pm
Forum: Battery Technology
Topic: Help request- to wire a Lipoly cell monitor array
Replies: 9
Views: 1275

Resistors in series will be fine as long as the LED is off. Once the LED turns on, there will be 120mv voltage drop, which will sort of latch it on until the voltage rises by more than 120mv. I gues if you have a 10 ohm resistor on both legs, the drop would be 240 mv. I wonder if a 1 ohm or 5 ohm re...
by fechter
Mar 24, 2007 1:08 pm
Forum: E-Bike Technical
Topic: Simulation Spreadsheets
Replies: 55
Views: 4947

What's the big peak in the torque curve? Somehow that doesn't look right.
by fechter
Mar 24, 2007 10:06 am
Forum: Battery Technology
Topic: Help request- to wire a Lipoly cell monitor array
Replies: 9
Views: 1275

TD is right about the VGA cable. It might only have 8 or so conductors, some of which are coaxial (PITA to mess with). I wouldn't worry too much about the voltage drop in the wire at 12ma, but resistors would throw it off. You could put a short piece of smaller gauge wire in series with the connecti...
by fechter
Mar 23, 2007 11:23 pm
Forum: E-Vehicles General Discussion
Topic: how many amps does your car starter draw?
Replies: 16
Views: 3544

OK, I peeked... but to make sure I understand: the ratio of the headlight current to voltage drop is equal to the ratio of the starter current to its voltage drop? :?: Right. The resistance stays the same. Ohm's law. Depending on the resistance of the wire and the sensitivity of the meter, the read...