Precautions when using our products

This section explains some of the points to be aware of when using our servo motor (hereafter, servo) for our radio control (hereafter R/C).Please read and fully understand the following information before using our R/C servo.

  1. Safety precautions
  2. The large R/C servos are extremely powerful. Misoperation can cause severe injury or damage. For example, the standard SSPS-105 can easily bend a 6-mm diameter steel rod. Always turn off the switch for the power supply for the servo when inspecting or maintaining the linkage or other areas. Also make sure that persons working with this equipment have a thorough understand of R/C technology.

  3. Summary of radio-control (R/C) servo
  4. servo block diagram
    1. Mechanical Design
      The R/C servo is comprised four blocks of a DC motor for operating power, gear unit, a servo drive amplifier that operates on R/C signal and potentiometers (POT) for detecting final shaft rotation position. Tonegawa servo's reduction unit has a DC motor pinion that operates sequentially in four trains. The final gear is mounted with a horn and the potentiometer that electrically senses the position of rotation.
    2. Electrical design
      The following items are mounted on one printed circuit board: the H-bridge circuit that turns the DC motor in the forward and reverse directions, the photo coupler that conveys the servo IC.Then the servo IC compares the R/C signal input pulse width and the POT position which is for internal one shot timer timing operation. In more specific terms, when the input pulse width at the stick of the R/C transmitter is in the neutral position (the center of the operation of the stick) is 1.5mS generally, the POT for the servo internal timer also be in the center position with 1.5mS timing. If the stick is then moved, the command input pulse width will change, the servo IC detecting the timing difference between the internal timer with POT position. Current will flow to the motor and the POT turns by means of the reduction unit to eliminate this difference as a servo loop. Once the command input pulse width and the POT position timing match, the motor drive current is stopped. The direction of rotation is determined by the pulse width time compare sign results. If the terminals for the motor are connected in reverse, those for the POT must also be connected for reverse direction.