User Guide

Lynxmotion SSC-32U Servo Controller Board

Electronics Guide

DigitalvsAnalogvs“Smart”Servos

AnalogServos

R/CServoBasics

When dealing with a Remotely Controlled (“R/C”) servo, it is important to know the following

terminology:

● Case (normally plastic, sometimes aluminum)

● DC motor (normally brushed, sometimes brushless or more exotic)

● Gears (which reduce the motor’s speed and increase the torque)

● Spline (connection from the last internal gear; fits into the servo horn to make it rotate)

● Horn (the plastic or metal part which can be used to connect other items)

● Potentiometer (an absolute angel sensor used to provide the servo’s position)

● Electronics (controls the motion)

● 3-pin cable and connector (0.1” standard spaced)

White / yellow / orange = Signal (Pulse)

Red = 4.8V to 6V (VS)

Black / brown = GND

R/C servos use a form of “Pulse Width Modulation” (PWM). In this case, the servo’s electronics

are waiting to receive a repeated 5V signal which it times to see how long that signal stays on.

For most RC servos, a 500us long pulse (0.5ms) at 5V would rotate the servo horn to -90

degrees; a 2500us (2.5ms) long 5V pulse would rotate the horn to +90 degrees; therefore a

1500us pulse corresponds to 0 degrees (centered). This pulse needs to be repeated every

~20ms.