Connecting Power and Motors to the Controller

Powering the Controller using the Motor Batteries

The AX2500/2850 included a DC/DC converter to generate the internal 12V required for its operation. The diagram on Figure 10 show how to wire the controller to a single battery cir- cuit and the two options for turning the power On and Off. The diagram shows two switches, although switching either one alone will power the controller Off.

In a typical configuration, it is recommended that the Motor Power be always applied and that the Controller’s Power be controlled using a switch on the Power Control wire (yellow). When the controller is Off, the output transistors are in the Off position and no power is drawn on the Motor Power battery.

For safety reasons, however, it is highly recommended that a way of quickly disconnecting the Motor Power be provided in the case of loss of control and all of the AX2500/2850 safety features fail to activate

Note, however, that eventually the motor batteries will get weaker and the voltage drop below the level needed for the internal DC/DC converter to properly operate. For all profes- sional applications it is therefore recommended to add a separate 12V (to 40V) power sup- ply to ensure proper powering of the controller under any conditions.

Important Warning

Unless you can ensure a steady 12V voltage in all conditions, it is recommended that the battery used to power the controller’s electronics must be separate from the one used to power the motors. This is because it is very likely that the motor batteries will be subject to very large current loads, which may cause the voltage to eventually dip below 12V as the batteries’ charge drops. The separate backup power supply should be connected to the Power Control input.

Important Warning

On versions of the AX2550 with PCB revision number lower than 5.2, the backup power supply applied on the Power Control wire must NEVER EXCEED 13V. Perma- nent damage may otherwise occur. PCB revision number can be found on the sticker on the case’s bottom.

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AX2500/2850 Motor Controller User’s Manual

Version 1.7. February 1, 2005

Page 28
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RoboteQ AX2550/2850 user manual Powering the Controller using the Motor Batteries