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Old 09-30-2003, 03:48 PM   #1
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on my cyclone, i just got it taped into my car, and i forgot the capacitor, does the cyclone really need it, or doesn't it.
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Old 09-30-2003, 03:58 PM   #2
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Yes, you dont want to run without it.
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Old 09-30-2003, 04:08 PM   #3
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why?, i never understood that, does it store power?
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Old 09-30-2003, 10:08 PM   #4
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Yes, it stores power. It is basically a little battery. It will give you more punch. I think you can run without one, but since they are so cheap and beneficial you might as well run one. I may have a cap that I could give you for a very small fee. I'll check my pit box in the morning.
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Old 09-30-2003, 10:17 PM   #5
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If I remember right, there is a small internal capacitor on the Cyclone, they didn't come with an external one, but it was always an option.
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Old 10-01-2003, 12:00 AM   #6
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Do I have to use the POWER CAPACITOR on the Atom / Cyclone if I am only using stock motors?

Yes. You have to install the Power Capacitor on the Atom / Cyclone even if you are using stock motors. The capacitor filters out all of the ripple on the input voltage. This ripple is due to the high frequency operation of the speed control. If you don't use the power capacitor you run the risk of causing internal damage to your speed control. Using the capacitor will result in an approximately 10 percent increase in the RPMs of your motor at partial throttle. It will also decrease the operating temperature of the Atom / Cyclone from 10-15 degrees, making the ESC more efficient.


The Cyclone speed control uses extremely high-speed switching circuitry for the drive power MOSFETS, which are used to control the power to the motor. This method of control is called PWM (pulse width modulation). To deliver 50% power to the motor at a PWM frequency of 5000 Hz, power is applied for 200 micro-seconds (s) and then turned off for 200s, repeatedly. In between being turned on and off, the transistors go through a transition period where they are inefficient. To minimize this inefficient period, the transistors must be switched on and off at a fast rate. Therefore, the speed of switching, which determines the overall efficiency of the speed controller, is important to the design of the speed control. The cyclone's switching speeds are the fastest in the industry, with a Rise Time (off to fully on) of less than 1 s and a Fall Time (fully on to off) of less than 0.8s.

There are several side effects with high speed switching. The more dangerous of these effects are the creation of high voltage spikes and radio noise. The value of these voltage spikes is determined by the current draw, the internal impedance of the battery, and the length of the wire connecting the speed control to the battery. During PWM switching, the battery voltage fluctuates up and down several volts (sometimes decreasing down to just a few volts during heavy acceleration). This fluctuation is called "ripple voltage," and can damage or cause improper operation of the radio system.

To provide smooth power to the speed control and the rest of the radio system, a very low impedance high-frequency capacitor is placed across the battery wires. This capacitor also delivers a large surge current during the valley portion of the ripple. Our test results have shown that at 50% power level, the use of a power capacitor adds about a 7-10% increase in motor RPM, reduces radio noise and increases the radio range. When the power capacitor is properly performing, it gets hot and must dissipate this heat or it will fail. As you have observed, the power capacitor is round in shape. Therefore, placing it inside the speed control would waste a large amount of space and prevent the heat from being dissipated.

Our competition uses several low frequency small capacitors, lined in parallel, inside their speed control to perform a similar function. We felt that doing this would reduce the system's reliability, as heat builds up in these capacitors and they tend to overload and fail. Our design philosophy delivers by far the best solution to this problem and provides flexibility in the usage of available space.
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