Connecting to a Voltage Source

Connecting to a Voltage Source

The analog inputs expect a DC voltage of 0 to 5V which can be sourced by any custom cir- cuitry (potentiometer, Digital to Analog converter).

The controller considers 2.5V to be the zero position (Motor Off). 0V is the maximum reverse command, +5V is the maximum forward command.

The inputs’ equivalent circuit is show in Figure 63 below.

+5V

14

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

AX2500 Internal Resistors

Analog

 

 

 

 

and Converter

 

 

 

 

 

 

 

 

 

 

Input 1 or 2

10

 

 

47kOhm

 

 

 

0V = Min

11

 

 

 

 

A/D

 

2.5V = Off

 

 

 

 

 

 

 

 

 

 

 

10kOhm

5V = Max

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

13

 

 

47kOhm

 

 

 

 

 

 

 

 

 

Ground

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FIGURE 63. Analog input circuit

Notice the two 47K resistors, which are designed to automatically bring the input to a mid- point (Off) position in case the input is not connected. The applied voltage must have suffi- cient current (low impedance) so that it is not affected by these resistors.

Connecting a Potentiometer

Figure 64 shows how to wire a potentiometer to the AX2500/2850. By connecting one end to ground and the other to 5V, the potentiometer acts as an adjustable voltage divider. The voltage will thus vary from 0V when the tap is at the minimum position and to 5V when the tap is at the maximum position.

The controller considers 2.5V to be the zero position (Motor Off). 2.5V is the potentiome- ter’s mid point position.

AX2500/2850 Motor Controller User’s Manual

109

Page 109
Image 109
RoboteQ AX2550/2850 user manual Connecting to a Voltage Source, Connecting a Potentiometer