The **L12-R** series (specifically the **Actuonix L12-R**) is a micro-linear actuator designed to function as a direct replacement for standard rotary servos. Unlike industrial linear actuators that use complex motor controllers, the L12-R "R" suffix stands for **RC Servo Compatibility**. ### 1. Key Internal Electronic Components The L12-R contains an internal closed-loop circuit. Here is the breakdown of its primary electronic parts: | Component | Function | | :--- | :--- | | **DC Brushed Motor** | The prime mover that converts electrical energy into mechanical rotation. | | **Internal Potentiometer** | A variable resistor linked to the actuator shaft that provides position feedback (the "sensor"). | | **Control PCB** | The "brain" that compares the incoming PWM signal with the current potentiometer position. | | **H-Bridge Driver** | Part of the PCB that reverses polarity to the motor to extend or retract the shaft. | | **3-Wire Interface** | Standard RC connector (Signal, Power, Ground). | --- ### 2. Technical Specifications (Electronic) The electronics are designed to operate within standard hobbyist and robotics voltage ranges. | Parameter | Value | | :--- | :--- | | **Input Voltage** | 4.8V to 6.0V DC | | **Control Protocol** | PWM (Pulse Width Modulation) | | **PWM Range** | 1.0ms to 2.0ms (typical) | | **Peak Current** | ~450mA to 1000mA (depends on load/model) | | **Wiring Color Code** | White (Signal), Red (V+), Black (GND) | --- ### 3. How the Electronics Function The L12-R operates on a **closed-loop feedback system**: 1. **Signal Input:** The actuator receives a 50Hz PWM signal. A pulse width of 1.0ms usually corresponds to fully retracted, and 2.0ms to fully extended. 2. **Comparison:** The internal Control PCB reads the voltage from the **Potentiometer**, which tells the board exactly where the shaft is currently located. 3. **Error Correction:** If the pulse signal demands a position different from the current one, the **H-Bridge** sends power to the motor. 4. **Stopping:** Once the potentiometer value matches the target PWM value, the board cuts power to the motor, holding the position. --- ### 4. Critical Usage Notes * **Voltage Sensitivity:** Exceeding 6V can burn out the internal control board. * **Stall Current:** If the actuator is physically blocked, the motor will continue to draw peak current, which can overheat the electronics. It is recommended to use a fuse or current limiter in sensitive applications. * **Non-Programmable:** Unlike the "P" (Potentiometer) or "I" (Integrated Controller) versions, the "R" version's logic is fixed for RC signals. ---