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Old 08-01-2009, 08:03 PM   #31 (permalink)
adamj12b
Master EcoModder
 
Join Date: Apr 2009
Location: Charlton MA, USA
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EVVette - '71 Chevy Corvette Coupe
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Quote:
Originally Posted by watahyahknow View Post
i was wondering about those controllers and how they work is it a solid state version of a row of relays raising the power in stages ? trying to see how its build i seen some drawings that look loke its the same scematic multiplied a couple of times
Hello whatahyaknow,

The controller uses 21 mosfet/diode pairs. A mosfet is basicially an digital on/off switch. These mosfets are rated to 130 Amps, and the diodes are rates to 90 Amps. I have derated to 80 Amps maximum continous current to keep them from being destroyed. The diodes are really the limiting factor.

There is a microcontroller that creats a frequency called PWM (Pulse Width Modulation). This is a high frequency square wave that tells the mosfets to turn on and off. With the PWM you can control the output voltage and current of the controller, Thus controlling the speed.

Here is the latest schematic of pauls controller. My controller uses this schematic as a base. I upgraded the diodes to the higher rated 90 amp ones, but these are twice as expensive Paul calls for 10 mosfet/diode pairs, All I did was increase this to 21 to increase the power of the controller.

Here is the schematic for refference.

-Adam

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You can download RTD Explorer for the Cougar controllers at www.EVVette.com
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