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  1. L

    Where to buy IRFB 4110 in singles

    The way i usually do it is: First melt solder with the iron and suck up the bulk of it with the solder sucker. Then use the solder braid to get anything left behind. I pinch the braid between the board and soldering iron and sort of wipe it around like a mop. Your mileage may vary, just do what...
  2. L

    The Fully Computerized Electric Vehicle

    I really really would like to build a motor controller with an imbedded microcontroller, i have a ton of pics lying around with a compiler and programmer ready to go. I just dont trust my programming skills when it comes to something that could end up killing me. "Hmm the throttle doesnt...
  3. L

    New approach to brushed motor controller

    well yeah from my perspective that is what im talking about. pwm effect isnt a real term that your going to find in a glossary, i assumed that this is what you were talking about, being that it is the cause for the curved torque curve that upset you oh so many months ago. And the thing thats...
  4. L

    New approach to brushed motor controller

    Safe your typical torque curve could also be a motor controller with no current limit and somebody holding full throttle. At this point your just not listening, i guess its nice to know that v=di/dt but it also requires visualizing what all those letters mean to understand the system...
  5. L

    New approach to brushed motor controller

    I dont really follow on this. E1 is chopped. E2 ideally should be straight dc but there is some ripple voltage due to ripple current. The output filter capacitor ( left out on motor controllers) filters out the ripple voltage. I dont really see unaccounted for energy in an ac component. use my...
  6. L

    New approach to brushed motor controller

    Okay first thing. By pwm effect do you mean the fact that input and output current dont match, or are you talking about the fact that your torque curve isnt flat. These are two very very different things, and neither have much to do with discontinous vs continuous operation. continuous...
  7. L

    New approach to brushed motor controller

    Safe for the love of god please trust us, i promise we are not attempting to mislead you. The pwm effect, if you are talking about a difference between input and output current occurs ANYTIME the duty cycle is less than 100%. Let me explain it in non mathematical laymens terms. Think of...
  8. L

    Lenz's Law

    Well if you have a high backemf motor then you just have a high voltage motor. No more no less. Typically high backemf translates into high torque per amp low speed per volt, low backemf is the inverse. It doesnt really dictate power. edit: theres more to it than that. look at axial flux...
  9. L

    PWM current multiplication effect Practical Branch

    I would say you pretty much got it. If the load is the same then thats all there is to it when your cruising. The only benefit i see as far as motor heating goes, and the math has to be done to see if there is a benefit, is to raise voltage and raise the gear ratio at the same time. This way...
  10. L

    PWM current multiplication effect

    The difference is in that with the resistor, the impedance is coming from resistance, thus you pretty much all loss. loss does equal heat. however with the magnetic ballast you do have impedance but a lot less actual resistance. An impedance can be looked at as an apparant resistance, for...
  11. L

    PWM current multiplication effect

    Yes it does, core loss from hysteresis :lol: edit: i want trying to say his equation was right Joe
  12. L

    The Great "Gearing vs Hub Motor" Debate

    Well im getting in late on this converation. My opinion on gears is that they cant hurt they can only help. They give you more torque to the wheels with less power required from the motor. It is in effect the torque output of the motor that leads to loss and motor heating at any given speed...
  13. L

    $20 2.5 HP DC motor for crazy HV experiments

    A light bulb really is a power resistor that gets so hot it glows when you look at it. They get hot, very hot, it still needs to be delt with. The high temperature is a plus and minus at the same time. Being that they run hot normally you dont have to heat sink it, theres a huge temperature...
  14. L

    $20 2.5 HP DC motor for crazy HV experiments

    A halogen light bulb should make a pretty good load. Two or three 500 watt bulbs can take all the power your setup can dish out. A 300 watt bulb is good for smaller setups. I'm not sure how badly resistance changes as they warm up, but a voltmeter and ammeter will give you all the information...
  15. L

    * * * Bike Designs and Theories * * *

    speed controller? Joe
  16. L

    Adjustable Power supply ???

    The variac should do that nicely. Only problem really is that theyre pricy, not nearly as pricy as a regulated supplly. All electronics has a 20 amp model for 200 bucks and a 10 amp for 155. They are unregulated so youll get voltage sag with load. Just like batteries. Also if you do go the...
  17. L

    Adjustable Power supply ???

    You could use a variac. Its an adjustable transformer that usually outputs 0 to whatever your input is. Then use a bridge rectifier and capacitor to get your dc out. 10 amps at 100 volts is a kilowatt thats expensive...
  18. L

    * * * The Minimal Ammeter? * * *

    I agree completely lowell, ive been there. Except how did you ever get 600 hp out of 2 liters. I thought 400 maybe 450 was the limit if you really know what your doing. Only exception is the skyline which has a small (still bigger than 2 liter) powerful motor but thats a six. Joe
  19. L

    My DIY 56V 20W Xenon lighting system my e-bike project

    I was under the impression automotive hids are damn expensive. Not sure if the bulb itself is cheap, but you cant just connect the bulb to the power supply it needs a driver. Maybe in a parts store theyre not so atrociously expensive? Actually now you got me wondering what it is the driver does...
  20. L

    The Great "Gearing vs Hub Motor" Debate

    Could you graph that with time as the x axis and speed as a dependent variable it would be easier to read. Joe
  21. L

    RPM Based Current Limit?

    Xyster you got it :!: we have to get safe to design us vacuum bubbles for our bikes. then somebody has to figure out how to move the vacuum bubbles around efficiently :?: Joe
  22. L

    Parallel Potentiometer As Cruise Control?

    Actually all the relays in this circuit are non latching, the relay in my circuit isnt latching either. Joe
  23. L

    RPM Based Current Limit?

    Sheesh i was agreeing with you I was saying that your right cruising at 10 mph on a bike that can go 40 is inefficient. The power required to maintain 10 mph places you on the right hand side of the efficiency curve at that specific voltage point and simple ill let you decide if i understand...
  24. L

    The Great "Gearing vs Hub Motor" Debate

    I forgot that detail, if your controller has regen it definetely is synchronous, the designs go hand in hand. But fechter what do you think about my idea in using a high voltage battery stepped down to the motor voltage. Seems like there are some benefits to it. Not worth building a controller...
  25. L

    RPM Based Current Limit?

    You are right, however what your noticing is a low load condition, i thought you were going to attack low rpm efficiency all over again. The truth is that a motor has a certain constant loss associated to it, just to make it turn, if your load is small in comparison to that, well the percentages...
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