I. Working Principle of Electronic Speed Controller
The desired engine speed is set using a speed adjustment potentiometer. The sensor measures the actual engine speed through the gear ring on the flywheel and sends it to the controller. The actual value is compared with the set value in the controller. The difference is processed and amplified by the control circuit and drives the actuator output shaft. The actuator pulls the fuel injection pump rack through the adjusting linkage to adjust the fuel supply, thereby maintaining the set speed.
This electronic speed governor can also select the degree of non-uniformity according to the needs of the engine's operating environment. During zero-delay speed regulation, the electronic control system eliminates the difference between the set speed and the actual speed caused by load changes, maintaining the engine at its original set speed. Depending on the unit's requirements, the non-uniformity potentiometer can also be adjusted to achieve a satisfactory static speed regulation rate.
The electronic speed governor is also equipped with a variety of accessory devices. Depending on the needs of the unit, the appropriate accessories can be installed to achieve functions such as automatic synchronization, load distribution and load preset.
The characteristic of an electronic speed controller is that it can independently determine speed control characteristics, and with all accessories installed, it can determine optimal torque characteristics, idle speed characteristics, and transient characteristics. Electronic speed controllers can adapt to the requirements of various different engine models.
II. Components of an Electronic Speed Controller
The components of electronic speed governors are largely similar; here, we take the E6-E30 type electronic speed governor as an example. The E6-E30 type electronic speed governors can be applied to speed control systems of internal combustion engines ranging from 150 to 5000kW.
This speed controller is an all-electric type, requiring no mechanical or hydraulic transmission. It consists of a speed adjustment potentiometer, a speed sensor, a controller, an actuator, and a safety circuit.
1. Speed sensor
It should acquire the highest possible signal frequency. The design uses a maximum signal frequency of 12000Hz. The formula for calculating the relationship between engine speed and frequency is as follows: f=nz/60
In the formula, f is the frequency (Hz), n is the engine speed (r/min), and Z is the tooth count of the sensor gear (or the number of teeth on the outer ring of the flywheel).
Ideally, the sensor should measure the rotational speed from the flywheel. During installation, the gap between the sensor and the top of the flywheel gear should be 0.4-0.8 mm.
2. Controller
Its function is to compare the actual rotational speed measured by the sensor with the set value, and then drive the actuator to perform the operation.
3. Speed adjustment potentiometer
It is used to set the frequency according to the maximum permissible speed of the engine. If the engine operating frequency is specified when ordering, the factory will set the frequency accordingly. If the operating frequency is not specified on the order, the frequency is set to 2000Hz at the factory. If this set frequency is between the engine's idling and maximum speed, the engine can be started and the "speedmax" (maximum speed) potentiometer adjusted to achieve the engine's maximum operating frequency.
4. Actuator
The actuator mainly consists of a DC motor, transmission gears, an output shaft, and a feedback component. Driven by the DC motor, its torque is transmitted to the output shaft via an intermediate gear. The feedback component transmits the actuator's operating status to the controller to form a closed-loop control system. The actuator's output shaft rocker arm is connected to the fuel injection pump rack via an adjusting linkage. 5. Fuse Circuit
The electronic speed control system is equipped with a safety circuit. When the sensor signal is interrupted, such as when the engine stops traveling due to a broken cable, it can stop the actuator and restore the output shaft rocker arm to the "0" position.
III. Applications of Electronic Speed Controllers
The primary application of electronic speed controllers (ESCs) is in toy models such as airplanes, cars, boats, flying saucers, and frisbees. These models use ESCs to drive motors to complete various commands, mimicking their real-world functions to achieve a similar effect to reality. Therefore, there are ESCs specifically designed for airplanes, and ESCs for cars, and so on. The function of an ESC is to control the motor to achieve specified speeds and movements. Therefore, ESCs also have a wide range of applications in production and daily life, such as ESCs in power tools, ESCs in medical equipment, ESCs in automotive turbines, and ESCs specifically designed for special fans, to name just a few. Some ESC manufacturers will even customize ESCs to your specific needs and motor parameters.
