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Unread 19-02-2007, 11:30
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WOOPS! shorted the deep cycle batt.
AKA: the supply seargent, Eugene
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Re: Capacitor Question

Quote:
Originally Posted by Ronald_raygun View Post
Allow me to clarify my previous post.

I meant 5 meters/second, not 5 milliseconds.

My weight budget is theoretically unlimited as long as the final machine fits into a 30cm x 30cm x 60cm box.

The motor voltage is somewhere in the neighborhood of 3volts. So, a final output voltage from the capacitor of 6volts should be doable. The amperage as well. 9A discharge from the supercap that I would like to use should be more than enough.

Choosing the capacitor isn't too much of a problem for me, unless the supercap battery link I posted earlier has some property which I am not aware of.

You're right, the motor is nowhere near 100% efficiency, but neither are my competitor's motors (we all use the same one). So for comparison purposes, I think I'm fine.




So far Al, you have provided me a wealth of information. Thank you for that.

However, I need to design a circuit which performs as follows:
  1. The fuel cell charges the capacitor before a race
  2. At the start of the race, the capacitor dumps its power into the motor, giving me a boost of speed similar to using NOS on a car.
  3. Once the capacitor is depleted, the circuit then directly routs the electricity from the fuel cell to the motor, so no energy is wasted charging the capacitor.

I have very little experience designing these kind of circuits, and that is where I need help. The supercapacitor's properties seem to be sufficient to provide just the power I need in order to get the car to jump out of the starting gate, and then pretty much coast to the finish line.

I hope my intentions are clearer.

For the circuit that disconnects the capacitor it would be great to use a relay even though my mentor calls it ancient arts. as for the capacitor try to look for transmitting capacitors used in amateur radio, not the big antenna tuner ones, but the smaller ones used in the actual radio


this capacitor will probably serve your needs http://www.digikey.com/scripts/DkSea...247035&Site=US
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Last edited by eshteyn : 19-02-2007 at 11:40.