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Old 08-12-2004, 07:23 PM   #1
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Default Does the receiver step down the voltage ....

Does the receiver step down the 7.2 volts for the servo, ESC and personal transponder or does the speed control do it ?
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Old 08-12-2004, 07:31 PM   #2
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The ESC does it.
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Old 08-12-2004, 07:33 PM   #3
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AE Racer , Thanks.
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Old 08-12-2004, 08:16 PM   #4
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Yeah the esc and motor drains the most voltage. It would be nice to have something to distribute the power more evenly where you wanted.
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Old 08-12-2004, 08:36 PM   #5
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The esc doesn't "drain" hardly any voltage at all. Not sure what you mean when you want the power distributed more evenly.
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Old 08-12-2004, 08:38 PM   #6
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I mean the most of the power is used by the motor and speed controller.
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Old 08-12-2004, 08:45 PM   #7
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ESC's use much less power in comparison to the motor. It's basically an electronic switch. If you had a mechanical speed control, that would be a different case, since lower speeds are achieved through a resistor.
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Old 08-12-2004, 08:55 PM   #8
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I have both electric and mechanical speed controls and I have noticed the difference in run times.
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Old 08-12-2004, 09:06 PM   #9
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ok.
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Old 08-12-2004, 09:10 PM   #10
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That's hilarious.
The ESC doesn't take up the power.
The motor is the one taking up 10's of Amps dude.

The runtime difference is because the mechanical SC gives the motor a variable voltage from 7.2 to 0. Electronic ESC's use pulses to drive the motor, but the pulses are always 7.2V strong. The ESC just pulses more often for more power and less often for less power. It's more efficient.

Power distribution is not an issue with RC cars. It is power consumption. Your Servo, ESC, Receiver all take up negligible power compared to the motor.

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Old 08-12-2004, 09:16 PM   #11
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Thanks. But me and 071crazy have went over that already.
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Old 08-12-2004, 09:17 PM   #12
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The runtime difference is due to the fact that a resistor drops the voltage to the motor, not because of the fact that it has "variable voltage". Energy is wasted from the resistor heating up.

Conservation of energy. It works.
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Old 08-12-2004, 11:29 PM   #13
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Hey genius, the voltage at the motor terminals varies given the resistance of the mechanical ESC. The resistor value changes, that is why the voltage changes. That's how your motor gets faster and slower. If the voltage wasn't variable you'd have a problem. Don't try to teach me ohm's law kid.

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Old 08-12-2004, 11:30 PM   #14
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You are also correct about the energy wasted in the resistor. But if you compare a constant voltage of 3.6 V vs. a 7.2V pulse width modulation at 50% duty cycle you will see you also save energy using the PWM.
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Old 08-13-2004, 02:36 PM   #15
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What did you do anyways, pick up a physics book and "learn" about ohm's law. Hilarious!!!
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