RoboteQ AX2550, AX1500 Power Fuses, Wire Length Limits, Important Warning, Version 1.9b. June 1

Connecting Power and Motors to the Controller

It will be safe to wire in parallel the controller’s outputs only after you have verified that both outputs react identically to channel 1 commands.

Xilinx

Jumper In for Single Channel

FIGURE 12. AX1500 Jumper setting for Single Channel Operation

MCU

Power Fuses

For low Amperage applications (below 30A per motor), it is recommended that a fuse be inserted in series with the main battery circuit as shown in the Figure 9 on page 30.

The fuse will be shared by the two output stages and therefore must be placed before the Y connection to the two power wires. Fuse rating should be the sum of the expected cur- rent on both channels. Note that automotive fuses are generally slow will be of limited effectiveness in protecting the controller and may be omitted in high current application. The fuse will mostly protect the wiring and battery against after the controller has failed.

Important Warning

Fuses are typically slow to blow and will thus allow temporary excess current to flow through them for a time (the higher the excess current, the faster the fuse will blow). This characteristic is desirable in most cases, as it will allow motors to draw surges during acceleration and braking. However, it also means that the fuse may not be able to protect the controller.

Wire Length Limits

The AX1500 regulates the output power by switching the power to the motors On and Off at high frequencies. At such frequencies, the wires’ inductance produces undesirable effects such as parasitic RF emissions, ringing and overvoltage peaks. The controller has built-in capacitors and voltage limiters that will reduce these effects. However, should the wire inductance be increased, for example by extending the wire length, these effects will

34 AX1500 Motor Controller User’s Manual Version 1.9b. June 1, 2007