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Do I need a fuse between the battery connection and the Sabertooth/Syren?


If this is more of a hobby project instead of an industrial product, most people do not use fuses. The Sabertooth has built-in current limiting.

We prefer that you fuse the motors rather than the battery leads, or if for safety reasons you need to fuse the battery that you do it at a much higher current than the motors. The reason is this:

Because Sabertooth is a regenerative driver, it relies on having a battery to put regenerated energy back into when you command a stop (and at other times). If you draw enough power to blow a battery fuse, all of a sudden the Sabertooth has nowhere to put the energy. It will see the fault, though, and try to stop the motor. It doesn't, however, have anywhere to put the energy (the mechanical energy of the vehicle and the electrical energy carried in the windings and the caps). So blowing a battery fuse will sometimes kill the driver -- which we can usually repair at no charge, but it's still annoying for all parties.

The better way to do it is to fuse the motor leads. If a motor fuse blows, the motor will freewheel, the Sabertooth will sit there contentedly, and the only thing you will have to replace is the fuse. A very large fuse (100 amps plus for a 2x25) on the battery lead will protect the wiring in the event of a battery lead short or motor driver failure.

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Article details
Article ID: 2
Category: Motor Drivers
Date added: 2012-03-30 00:45:14
Views: 7969
Rating (Votes): Article rated 3.5/5.0 (24)

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