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| What is PWM? | |
| PWM stands for Pulse-Width Modulation. ESCs pulse current to the motor in an ON-OFF manner. Changing the ratio of the ON time to the OFF time changes the speed of the motor. For example, at 80% speed, the current pulse is on 80% of the time and off 20% of the time. This cycle happens 60 times-per-second for low-frequency ESCs, and approximately 3,500 times-per-second in the Novak high-frequency ESCs. | |
| What is BRAKE PWM FREQUENCY? | |
| Brake PWM Frequency is the frequency at which the duty cycle information is being sent from the speed control to the motor for braking. It also controls the deceleration characteristics of your vehicle with respect to trigger movement in the Full Brake direction. Brake PWM Frequency is measured in Hertz (Hz). Click here to find out what the effect is of changing the Brake PWM frequency. | |
| What is DRIVE PWM FREQUENCY? | |
| Drive PWM Frequency is the frequency at which the duty cycle information is being sent from the speed control to the motor during forward drive (How many times-per-second the motor is being cycled ON and OFF to control its speed). It also controls the acceleration characteristics of your vehicle with respect to trigger movement in the Full Throttle direction. Drive PWM Frequency is measured in Hertz (Hz). Click here to find out what the effect is of changing the Drive PWM frequency. | |
| What does SENSORED mean? | |
| Sensored refers to the connection between a brushless ESC and motor that allows the ESC to know the precise position of the rotor in relation to the windings in the motor for the best in low speed drivability and braking. A motor being sensored allows for smooth accelleration without "cogging." A motor being sensored has no effect on the power that the motor can produce. | |
| What does SENSORLESS refer to? | |
| Sensorless refers to lack of communication connection between a brushless motor and it's ESC. A sensorless system will not have the same low speed drivability or braking response as a sensored system. Sensorless motors are no faster than sensored motors. | |
| What is PROPORTIONAL CONTROL? | |
| This means that the speed of the car responds identically to throttle movement on the transmitter. | |
| Will my car go faster with an ESC? | |
| Yes. The efficiency of an ESC is much higher than that of a mechanical or resistor-type speed control. Not only will the car go faster, but it will also run longer. | |
| What is ON-RESISTANCE? | |
| This is the restriction an ESC offers to the flow of current to the motor at full speed. The lower the on-resistance, the higher the efficiency (performance) of the ESC. | |
| What is the difference between CONTINUOUS CURRENT and PEAK CURRENT? | |
| Continuous current is the MOSFET's ability to handle current over a continuous period. Peak current (or surge current) is the MOSFET's ability to handle high current surges for a very short duration (1-2 milliseconds). Both ratings are specified at the MOSFET's junction temperature at 25° C. | |
| What is BEC? | |
| BEC is the abbreviation for Battery Eliminator Circuit, which is a built-in voltage regulator that supplies a constant voltage (usually 5 or 6 volts) to the receiver and servo. The receiver does not need an external battery pack, but one can be used if desired. | |
| What is THERMAL PROTECTION and how does it work? | |
| Thermal Protection is a built-in sensor which shuts down the MOSFET(s) when its temperature exceeds a preset level. In our high-frequency ESCs and our Chargers, this temperature is 230°F (110°C). The Thermal Protection circuitry provides protection from overloads. Some of our ESCs have Dual-Level Thermal Protection, which cuts the throttle in half when the ESC's temperature reaches unsafe levels. If the temperature continues to climb, the ESC will shut down. | |
| What is a MOSFET? | |
| MOSFET is the abbreviation for Metal Oxide Semiconductor Field Effect Transistor. A MOSFET is a voltage controlled power device that is capable of handling large electrical current flow. This type of transistor allows us to design small speed controllers capable of handling the demanding requirements of R/C racing. | |
| What is a DIODE? | |
| A diode is a two-terminal semiconductor device, that acts as a one-way valve which allows the electrical current to only flow in one direction. Typically, a Silicon diode has a forward voltage drop of approximately 0.7 to 1.0 volts across the two terminals at full load. | |
| What is a SCHOTTKY DIODE? (pronounced Shot-Key) | |
| A Schottky diode is a special type of high-speed diode that has a very low forward-voltage drop. This means it offers very little resistance to the flow of current in one direction. The average Schottky diode forward-voltage drop is typically 0.30 to 0.45 volts under full load. A Racing Schottky diode module is available Novak Accessory Kit #5636.MORE INFO | |
| What is a POWER CAPACITOR? | |
| A power 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 on high-frequency ESCs 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 RPM of your motor at partial throttle. It will also decrease the operating temperature of the ESC by 10-15 degrees, making the ESC more efficient. | |
| What is REVERSE VOLTAGE? | |
| Reverse voltage is when the power source (battery pack) is connected backwards to the ESC's red and black wires. | |
| What is SOLID STATE REVERSE VOLTAGE PROTECTION? | |
| Our proprietary reverse voltage protection circuit uses a MOSFET to control the flow of current to the brake and the ESC's control circuitry. This circuit shuts off the flow of current in case reverse voltage is applied, thus preventing any damage to the ESC. Absence of any mechanical fuse means no fuses to change or repair. | |
| What is a CURRENT LIMITER? | |
| This is a feature found in our older models such as the Racer-EX and Tempest ESCs. The purpose of the current limiter is to allow the user the ability to adjust the maximum amount of current to be passed through the ESC upon acceleration. The current limiter functions similarly to an electronic slipper clutch. | |
| What is the difference between HIGH FREQUENCY and LOW FREQUENCY ESCs? | |
| Low frequency ESCs normally use 60 Hertz PWM to control the motor. High frequency ESCs use 1,000-23,400 Hertz. | |
| What are the advantages of HIGH FREQUENCY ESCs? | |
| There are three major advantages: (1) the throttle response is linear since high frequency ESCs are completely digital; this makes the vehicle much easier to drive; (2) run-time is increased since the MOSFETs are more energy-efficient and can recharge the battery during braking; (3) motor life is increased since the motor commutator sparking (or arcing) is drastically reduced. | |
| What is REGENERATIVE POWER? | |
| While braking, energy generated by the motor is fed back through the ESC into the battery pack; this can only be accomplished when the power MOSFETs are turned ON and OFF at a very fast rate, such as in our high frequency ESCs. This regenerative power provides increased battery life. | |
| How is RUN TIME related to the frequency of the ESC? | |
| Because high-frequency ESCs are more energy-efficient than low-frequency ESCs, and they recharge the battery while braking, the run time is increased. All Novak high-frequency ESCs use the optimum frequencies that result in the best compromise between power and long run-time. | |
| Why are high frequency ESCs easier on motors? | |
| The motor's current pulses at a faster rate, allowing less time for current to flow through the motor when the brush shorts across two of the three motor poles. This greatly reduces sparking (or arcing) between the brushes and commutator and increases motor life. | |
| Why do high frequency ESCs make a high-pitched noise before the motor starts turning? | |
| A DC motor has the same two basic components as a speaker, a coil and a DC magnet. When 2,500 Hertz current pulses are applied to the motor, it turns into a speaker and you can hear a high pitched whine. Although this sound is always being produced, the motor's rotational noise at higher RPMs drowns it out. | |
| What is DEAD BAND? | |
| Dead Band is the space between Minimum Brake and Minimum Drive, with Neutral located at the center of this space. This value is usually given as as a percentage, most Novak ESCs are set to a 5% default dead band value. | |
| What is DRAG BRAKE? | |
| Drag Brake turns the dead band area between throttle and brakes into a preset amount of brakes, which eliminates the time, or dead space, to travel from brakes to throttle. | |
| What is DRAG BRAKE FREQUENCY? | |
| Drag Brake Frequency is the frequency at which the duty cycle information is being sent from the Cyclone to the motor for Drag Braking during neutral/deadband. Drag Brake Frequency also controls the deceleration characteristics of the vehicle with Drag Brake during neutral/deadband. Drag Brake Frequency is measured in Hertz (Hz). | |
| What is MINIMUM DRIVE? | |
| Minimum Drive is the amount of drive applied with the first pulse of transmitter throttle information. This value is usually given in a percentage ranging anywhere between 1% and 12% of full throttle. The higher this value the less smooth the initial amount of throttle will be. For modified motors or lower traction conditions, a lower minimum drive value is best. For stock, 19 turn motors, or high traction conditions, a higher minimum drive value can be used. Most default settings are 3%. | |
| What is MINIMUM BRAKE? | |
| Minimum Brake is the amount of brake applied with the first pulse of transmitter throttle information. On most Novak ESCs this default value is set to 20% of full braking force. | |
| What is POLAR DRIVE TECHNOLOGY? | |
| Polar Drive Technology allows the circuitry to stay cool while enabling the speed control to handle higher powered motors. This results in smoother performance, increased acceleration, longer run time and increased radio system range.MORE INFO | |
| What are DRIVE PROFILES? | |
| Drive profiles are set programs within an ESC that have stored values for Drive Frequency, Minimum Drive, Dead Band, Brake Frequency, and Minimum Brake that are set up in certain ways to give the best performance for certain applications or allow for fine tuning of throttle response and feel. | |
| What is SMART BRAKING? | |
| Smart Braking is the Novak software that allows for smooth, controllable braking while using a reversable esc without fear of the motor engaging in reverse before the car has come to a complete stop. | |
| What is SMART BRAKING II | |
| Smart braking II takes the original smart braking software and makes braking and reversing while using a reversible ESC even more controlable. Smart braking II allows the driver full use of brakes without fear of reverse being engaged until the throttle is returned to neutral and "shifts" into reverse. This allows for easier transitions into reverse which in turn results in longer car life and is easier on your batteries and motors. | |
| What is the difference between an electronic speed control (ESC) and a mechanical speed control? | |
| Mechanical speed controls regulate the speed by lowering the voltage to the motor through a resistor. This is an inefficient technique. Also, mechanical speed controls require a servo for operation and only offer 2-3 steps of control. An ESC regulates the speed by PWM. This method offers many more steps of control, is highly efficient, and results in smooth, proportional throttle control, greater speed and longer run time. | |