RoboteQ AX500 Tachometer or Encoder Mounting, Tachometer wiring, Speed Sensor and Motor Polarity

Closed Loop Speed Mode

Tachometer or Encoder Mounting

Proper mounting of the speed sensor is critical for an effective and accurate speed mode operation. Figure 1 shows a typical motor and tachometer or encoder assembly.

Analog Tachometer

Speed feedback

FIGURE 43. Motor and speed sensor assembly needed for Close Loop Speed mode

P iti F db k

Tachometer wiring

The tachometer must be wired so that it creates a voltage at the controller’s analog input that is proportional to rotation speed: 0V at full reverse, +5V at full forward, and 0 when stopped.

Connecting the tachometer to the controller is as simple as shown in the diagram below.

1kOhm

Zero Adjust 100 Ohm pot

1kOhm

	+5V 14
Max Speed Adjust	Ana 1: 11
10kOhm pot
	Ana 2: 10
	Ana 3: 12
Tach	Ana 4: 8

Ground 5

Internal Resistors and Converter

47kOhm

A/D 10kOhm

47kOhm

FIGURE 44. Tachometer wiring diagram

Speed Sensor and Motor Polarity

The tachometer or encoder polarity (i.e. which rotation direction produces a positive of negative speed information) is related to the motor’s rotation speed and the direction the motor turns when power is applied to it.

In the Closed Loop Speed mode, the controller compares the actual speed, as measured by the tachometer, to the desired speed. If the motor is not at the desired speed and direc- tion, the controller will apply power to the motor so that it turns faster or slower, until reached.

74 AX500 Motor Controller User’s Manual Version 1.9b. June 1, 2007