Connecting Sensors and Actuators to Input/Outputs

When the controller is used in RS232 mode, this output can be turned On and Off using the !C (On) and !c (Off) command strings. See “RS232 Commands Set” on page 92 for more information.

Important warning:

This output is unprotected. If your load draws more than 2A, permanent damage may occur to the power transistor inside the controller. A 1A fuse may be used in series with the load for increased protection.

Overvoltage spikes induced by switching inductive loads, such as solenoids or relays, will destroy the transistor unless a protection diode is used.

Connecting devices to Output D

Output D is a low-current, unbuffered output. When Off, this output will be pulled to ground through a 10Kohm resistor. When On, this output will be pulled to around 4.5V through that same resistor.

The D output cannot drive any load directly and requires an external transistor or solid state relay to drive high current accessories. Because they are external, the size, voltage, and power of these transistors can be selected to best suit a particular need.

The diagram on Figure 24 shows how to drive a large inductive load using the D output and a Power MOSFET widely available at most electronic component distributors. The MOS- FET must conduct with a gate voltage of 4V or higher.

The D output can be toggled On and Off using the Channel 3 Joystick when in the R/C mode. See “Activating the Accessory Outputs” on page 83 for more information.

When the controller is used in RS232 mode, this output can be turned On and Off using the !D (On) and !d (Off) command strings. See “RS232 Commands Set” on page 92 for more information.

5to 24V DC

+

-

Use Diode for Relay, Valve Motor, Solenoid

or other Inductive Load

IRF1010

Output D 12

AX2500 Internal Buffer and Resistor

10kOhm

1MOhm

Ground 5

FIGURE 24. Connecting external MOSFET and load to Output D

54

AX2500/2850 Motor Controller User’s Manual

Version 1.7. February 1, 2005

Page 54
Image 54
RoboteQ AX2550/2850 user manual Connecting devices to Output D, Connecting external Mosfet and load to Output D