Emax SimonK Series 12A Brushless ESC for Multirotor, Quadcopter & RC Aircraft

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The Emax SimonK Series 12A Brushless Electronic Speed Controller (ESC) is a reliable and high-performance speed controller designed for multirotors, quadcopters, RC aircraft, helicopters, and UAVs Featuring the optimised SimonK firmware, this ESC provides ultra-fast throttle response, smooth startup, excellent low-speed performance, and precise motor control for demanding flight applications.

Supporting 2S to 4S LiPo batteries, the ESC delivers a continuous current of 12A with a 15A burst current for short-duration peak loads. It includes a built-in 5V 1A UBEC, eliminating the need for an external receiver power supply in most applications.

The ESC is equipped with intelligent protection features including low-voltage protection, over-temperature protection, and power-on self-test for enhanced safety and reliability. Users can configure throttle range and operating parameters using a compatible programming card or transmitter, ensuring compatibility with a wide range of RC receivers.

Compact, lightweight, and highly efficient, the Emax SimonK Series 12A ESC is an excellent choice for FPV racing drones, multirotor platforms, and custom UAV builds.

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Key Features

• Genuine Emax SimonK Series ESC.
• 12A continuous output current.
• 15A burst current.
• Supports 2S–4S LiPo batteries.
• Optimised SimonK firmware.
• Built-in 5V/1A UBEC.
• Fast throttle response.
• Excellent low-speed motor control.
• Configurable throttle range.
• Remote and programming card configuration.
• Low-voltage protection.
• Over-temperature protection.
• Power-on self-test.
• Independent MCU and BEC regulation for improved anti-interference.
• Lightweight and compact design.

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Technical Specifications

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Why Choose SimonK ESC?

SimonK firmware has become one of the most trusted ESC firmware platforms in the RC hobby industry due to its fast processing speed and superior motor control. Unlike conventional ESC firmware, SimonK firmware significantly reduces throttle delay, providing smoother motor response and more precise control during takeoff, hovering, aerobatics, and landing.

The ESC is manufactured using high-quality MOSFETs and electronic components to ensure high efficiency, low heat generation, and long operational life. Multiple current ratings ranging from 6A to 80A allow users to select the perfect ESC for small indoor aircraft, racing drones, or larger fixed-wing models.

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Advanced SimonK Firmware

The SimonK firmware has been specially optimised to deliver excellent drive performance and stable motor operation.

Benefits include:

• Ultra-fast throttle response

• Smooth motor startup

• Reduced throttle latency

• Improved flight stability

• Efficient motor synchronisation

• Better power delivery

• Enhanced flying precision

• Reliable operation under varying loads

The firmware continuously monitors motor operation to maintain stable performance even during rapid throttle changes.

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Built-in BEC (Battery Eliminator Circuit)

Most SimonK ESC models include a built-in Battery Eliminator Circuit (BEC) that supplies regulated 5V power directly to the receiver and servos.

Benefits of the integrated BEC include:

• Eliminates the need for a separate receiver battery

• Simplifies wiring

• Reduces overall aircraft weight

• Provides stable voltage to receiver electronics

• Improves installation convenience

Depending on the model selected, the ESC features either a Linear BEC or a Switching UBEC, offering output currents from 0.8A to 5A.

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Intelligent Protection System

The SimonK ESC incorporates multiple electronic protection systems designed to maximise reliability and extend the life of both the ESC and the connected motor.

Low Voltage Protection

When the battery voltage falls below the preset threshold, the ESC automatically activates battery protection to prevent over-discharge.

Selectable protection voltages include:

• 2.8V per cell

• 3.0V per cell

• 3.2V per cell

The ESC automatically detects the number of connected LiPo battery cells and calculates the total cutoff voltage accordingly.

For example:

• 2S Battery → Cutoff based on 2 cells

• 3S Battery → Cutoff based on 3 cells

• 4S Battery → Cutoff based on 4 cells

This helps extend battery life while preventing permanent battery damage.

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Cutoff Modes

Users can choose between two battery protection methods.

Soft Cut

The ESC gradually reduces motor power once the battery reaches the programmed low-voltage threshold.

Advantages:

• Gives the pilot time to safely land.

• Prevents sudden power loss.

• Protects the battery from excessive discharge.

Hard Cut (Cut-Off)

The ESC immediately stops motor output when the programmed cutoff voltage is reached.

Recommended for applications where maximum battery protection is required.

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Overheat Protection

The ESC continuously monitors its operating temperature.

When excessive heat is detected, output power is automatically reduced to protect the internal MOSFETs and electronic circuitry.

Typical protection stages:

• Above 100°C → Output power reduced below 75%

• Above 105°C → Output power reduced below 50%

• Above 110°C → Output power reduced below 25%

• Above 115°C → Output power reduced below 6.25%

Once the ESC cools down, normal performance is automatically restored.

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Signal Loss Protection

If communication between the receiver and ESC is interrupted:

• Motor power is gradually reduced.

• The motor safely stops.

• Power resumes automatically when a valid receiver signal is restored.

This feature improves operational safety during flight.

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Throttle Range Calibration

The SimonK ESC supports throttle endpoint calibration to ensure compatibility with virtually all RC transmitters.

Calibration ensures:

• Accurate minimum throttle detection

• Correct maximum throttle detection

• Smoother acceleration

• Improved throttle linearity

• Better motor response

• Reliable startup

Throttle calibration is recommended whenever changing transmitters or receivers.

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Fully Programmable ESC

The SimonK Series ESC allows users to customise motor performance through several programmable parameters.

These settings can be adjusted using a programming card or directly through the transmitter.

Brake Mode

Available options include:

• OFF

• Low

• Mid-Low

• Middle

• Mid-High

• High

Brake mode is particularly useful for fixed-wing aircraft where quick propeller stopping is required during gliding.

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Timing Mode

Motor timing can be optimised for different brushless motors.

Available timing options:

• Low

• Mid-Low

• Middle

• Mid-High

• High

Lower timing generally suits high-inductance motors, while higher timing may improve performance with low-inductance or high-KV motors.

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Start Force

Adjusts the amount of startup power supplied to the motor.

Multiple startup force settings allow reliable motor startup for different propeller sizes and motor loads.

Ideal for:

• Large propellers

• High torque motors

• Lightweight racing aircraft

• Multirotors

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Throttle Curve

Users can configure the throttle response curve to match different flying preferences.

Options include:

• OFF

• Low

• Middle

• High

This allows smoother or more aggressive throttle behavior depending on the application.

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PWM Control Frequency

The ESC provides selectable motor drive frequencies for optimized efficiency and smooth motor operation.

Available frequencies include:

• 8 kHz

• 22 kHz

Users can choose the frequency best suited to their motor type and application.

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Programming Methods

The ESC supports two programming methods for maximum flexibility.

Method 1 – Programming Card

A compatible SimonK Programming Card provides quick access to all adjustable parameters.

Benefits include:

• Fast configuration

• Simple operation

• Instant parameter changes

• Easy viewing of current settings

Ideal for users who frequently tune their aircraft.

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Method 2 – Transmitter Programming

No programming card is required.

Using only the RC transmitter, users can configure:

• Brake Mode

• Timing Mode

• Start Force

• Throttle Curve

• PWM Frequency

• Low Voltage Protection

• Cutoff Mode

The ESC uses audible beep sequences to guide users through each programming option.

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Important Notes

• Select the ESC current rating according to your motor's maximum current consumption.

• Use only compatible LiPo or Li-ion battery packs within the supported cell range.

• Ensure adequate airflow around the ESC during operation.

• Perform throttle calibration before the first use.

• Disconnect the battery immediately after flying.

• Never reverse battery polarity.

• Avoid operating the ESC in wet or highly humid environments unless additional waterproofing is applied.

• Inspect all solder joints and connectors before each flight.

• Always use a propeller suitable for your motor and ESC rating.

• Read the instruction manual carefully before programming or operating the ESC.

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Applications

• FPV Racing Drones
• Quadcopters
• Multirotor UAVs
• RC Airplanes
• RC Helicopters
• Brushless Motor Control
• DIY Drone Projects
• UAV Development
• Robotics Projects
• Educational Drone Kits
• RC Hobby Electronics
• Custom Aircraft Builds

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Precautions

• Use only compatible 2S–4S LiPo batteries.
• Verify motor and battery wiring before powering the ESC.
• Ensure adequate airflow for cooling during operation.
• Do not exceed the rated current of 12A for continuous use.
• Calibrate the throttle range before the first flight.
• Disconnect the battery before installation or maintenance.
• Avoid reverse polarity connections.
• Inspect wiring and connectors before each use.

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Package Includes

• 1 × Emax SimonK Series 12A Brushless ESC with 5V 1A UBEC