How to choose Electronic Speed Controller for FPV Drone?

Best ESC for FPV Drones: Comprehensive Electronic Speed Controller Buyer’s Guide

The electronic speed controller (ESC) plays a crucial role in FPV drones as it provides stability and power. It serves as the bridge between the flight controller and the motors. For quadcopters, each fpv brushless motor requires its own dedicated ESC. Therefore, a quadcopter typically needs four ESCs.

The primary function of an ESC is to receive signals from the flight controller and power from the battery, which it then uses to spin the brushless motor. Although this may seem straightforward, the process is more intricate than it appears. While smaller drones may utilize brushed motors, brushless motors are commonly found in mini quadcopters used for racing and freestyle flying.

Unlike brushed motors that rely on physical contact between brushes and windings to rotate, brushless motors do not have such components. Instead, they employ a different approach to convert direct current (DC), the one-way flow of electrons, into alternating current (AC). This conversion is facilitated externally through the use of an ESC.

Different Types of FPV Drone ESCs

Like everything else in a drone, the ESC is constantly evolving and adapting to the pilot’s needs. ESC plays a vital role in the performance of drones, so ESC hardware is constantly improving. There are several basic types of ESCs available. Electronic speed controllers (ESCs) on the market are mainly controlled by BLHeli_32 or KISS firmware running on an onboard 32-bit processor. Just last year, most ESCs only used 8-bit processors, and only a few high-end ESCs like KISS were 32-bit. Compared to D-SHOT 600, faster digital protocols like D-SHOT 1200 can be utilized by 32-bit ESCs for communication. The 32-bit ESC also has other functions, such as controlling light-emitting diodes (LEDs), changing the direction of motor rotation for turtle mode (which uses the motors to self-righte an inverted drone), and more. In addition, these ESCs possess the capability of telemetry that enables them to transmit relevant information from the ESC to the flight controller, which includes details such as RPM, temperature, and current draw.While the capabilities of 32-bit ESCs are a nice addition, many current 8-bit ESCs still perform very well when running the widely used ESC firmware called BLHeli_S.

When it comes to ESC hardware, an important factor to consider is whether the ESC is a standalone unit mounted on the drone arm in between the flight controller and the motors., Alternatively, is the motor powered by a 4-in-1 ESC that consolidates all four ESCs onto a single circuit board and mounted beneath the flight controller in the primary stack?For a lighter structure, or for a more compact appearance, many pilots choose to purchase 4-in-1 ESCs. They usually have a built-in voltage regulator and can also act as a power distribution board (PDB).

FPV Drone ESC Ratings

The ratings of ESCs depend on the amount of current they can deliver to the motor. ESCs work by turning on the power to the motor coils at a very fast rate. This switching is controlled by a microprocessor and performed by transistors called MOSFETs (often called FETs).

Amperage

The size and quality of these FETs determine the current (amperage) that can pass through the ESC. ESCs are typically rated based on their current capacity, indicated by values such as “30 amps” or “25 amps”. These numbers usually represent the continuous current that the ESC can handle. For short periods of time (usually less than 10 seconds), ESCs can handle slightly higher currents. It is common to see ESCs labeled “30 amp” ESCs that are capable of “bursting” 40 amps. When buying an ESC, it’s crucial to take its current rating into account. It’s always preferable to opt for an ESC that can provide higher current levels even if it means a larger size or higher cost, rather than risking damage by providing insufficient current. Motors with larger sizes typically require more current, and propellers with greater pitch or size will also draw more current. Currently, a 30 amp ESC using a 4-cell battery (4S) is sufficient for most pilots.

Voltage

Currently, most UAV operators use 4S, which operates at 16.8 volts. However, this has recently begun to change. To improve drone performance, some competition organizers are promoting the use of 5S and 6S batteries with higher voltages among pilots.In addition to amperage, ESCs are rated for their ability to handle voltage. Some ESCs are rated for 3S-4S, while others are rated for up to 6S. The power of a motor can be measured in watts, which is voltage multiplied by amps (volts x amps = watts). Therefore, it is interesting to note that as the voltage increases, the current intensity decreases to keep the total power output of the motor the same. This means that a higher voltage battery can deliver the same motor power output with lower current draw. Or, if the voltage increases and the pilot chooses to increase the throttle.

Select the right FPV drone electronic speed controller for your motor, propeller and battery combination

When selecting an ESC, it is important to consider 3 main considerations. 3 considerations for ESC selection include

• Motor size: The motor’s size play a significant role in determining the ESC’s current capacity requirements.
• Propeller: The choice of propeller will also determine the current rating of your ESC. Will your drone spin a 3, 4, 5 or 6 inch propeller? What kind of performance do you want, and therefore what propeller pitch will you use?
• Batteries: Will you be us Will your drone spin a 3, 4, 5 or 6 inch propeller?ing 3-cell batteries, or 4, 5 or even 6-cell batteries? Both ESC and batteries are rated by amperage.

Let’s say you are interested in racing drones. Modern competition drones almost always use 5″ high pitch propellers. To get these large pitch propellers spinning at high RPM, pilots choose motors with sizes such as 2207, 2450kv, etc. The motors have aggressive tilt struts and can pull up to 40 amps of current. Therefore, it is important to select the correct ESC so that the FET on the ESC is not damaged by the current strength and fails during the race. Therefore, it is best to design your drone for your specific needs and applications. However, choosing the voltage of the ESC is much easier because ESCs have ratings on them that indicate the battery voltage (S) they can handle. In general, for a 4S drone running a 5-inch propeller

FPV drone electronic governor firmware

The ESC receives the throttle signal from the flight controller. For several years, the primary means of conveying information to the ESC regarding the motor’s speed was through a pulse width modulated signal (PWM). However, modern flight controllers and ESCs communicate using a faster digital protocol called D-Shot. The ESC will receive a signal from the flight controller and convert that signal into motor speed. This change in motor speed can happen very quickly, due in part to the fast communication between the flight controller and the ESC, and the connections between the ESC and the motors. The FPV drone electronic speed controller utilizes an onboard microprocessor, so firmware is required to control the hardware. The firmware plays a crucial role in deciding the communication protocol that will be utilized by the flight controller to interact with the ESC.

• BLHeli: This was found on older 8-bit ESCs. It is capable of running one-time protocols. A subsequent model of 8-bit microprocessor called the F390 was able to process the faster analog Multishot.
• BLHeli_S: This is also present on the 8-bit ESC, but has more modern hardware, runs quieter, and is capable of running all protocols (Oneshot, Multishot) up to D-Shot 600.
• BLHeli_32: This is a relatively new firmware that will run on the new 32-bit ESC. It’s capable of faster D-Shot iterations like the D-Shot 1200, with features like telemetry.
• KISS: This is a proprietary ESC firmware that can only run on KISS ESC. It has Oneshot and D-Shot capabilities and has telemetry and other features.

This firmware is user upgradeable. Settings on the ESC can be changed using software on Mac and PC.

Capacitor

Electronic speed controllers for FPV drones of the past few years usually come with electrolytic capacitors. With microtetrodes becoming more popular, and to save size and weight, most ESCs are no longer equipped with these large electrolytic capacitors. With the advancements in flight controllers and ESC firmware and hardware, as well as the increase in motor power due to the use of stronger magnets, it has become evident that the absence of capacitors could have an adverse impact on the performance These ESCs are also capable of telemetry, sending information from the ESC such as RPM, current draw, and temperature from the ESC to the flight controllerof drones. Capacitors serve as electronic storage units, which can significantly improve the drone’s power supply when placed near the battery leads. By integrating capacitors into the PDB, the power surges produced by the brushless motor during braking can be effectively absorbed and minimized. In this way, capacitors greatly help protect electronics, eliminate electronic noise in FPV video feeds, and can even greatly improve the performance of drones. Many times a drone may experience some “jerking”, especially if there are powerful motors or some gyroscopes on the flight controller. The addition of a low-ESR electrolytic capacitor, which has a minimum rating of 440 µF and 25 volts (v), connected across the battery lead of the PDB can provide an instant boost in performance.Many pilots have had great results using 1000 µF, 35v capacitors, even though the build may be twitchy. Adding a low-ESR electrolytic capacitor rated at least 440 µF and 25 volts (v) across the battery lead of the PDB can immediately improve performance. Many pilots have had great results using 1000 µF, 35v capacitors, even though the build may be twitchy. The performance of the PDB can be instantly enhanced by including a low-ESR electrolytic capacitor with a minimum rating of 440 µF and 25 volts (v) connected across the battery lead.Many pilots have had great results using 1000 µF, 35v capacitors, even though the build may be twitchy.

Last conclusion

The FPV UAV electronic governor is a key component between the flight control, battery and motor. There is a wide range of ESCs available that cater to the requirements of various kinds of drones. Whether it’s small-sized 2-inch drones, high-powered racing drones, or long-range camera drones, there are numerous options to choose from.It is important to match the ESC to the flight style and intended application. However, it is best to choose an ESC that can handle higher currents and voltages than you plan to use, as you give yourself room to grow and a margin of safety.