Wednesday, 9 July 2008


Here is a little about the Sabertooth 25A system I am getting. A bit of overkill, but I have read in a few places that under stress that wiper motors can produce 30A peak current! So I don't want to take any risks.

The Sabertooth 2X25 is one of the most versatile, efficient and easy to use dual motor drivers on the market. It is suitable for high powered robots - up to 100lbs in combat or 300lbs for general purpose robotics.

Out of the box, the Sabertooth can supply two DC brushed motors with up to 25A each. Peak currents of 50A per channel are achievable for a few seconds.

Overcurrent and thermal protection means you'll never have to worry about killing the driver with accidental stalls or by hooking up too big a motor.

Sabertooth allows you to control two motors with: analog voltage, radio control, serial and packetized serial. You can build many different robots of increasing complexity for years to come with a Sabertooth. Sabertooth has independent and speed + direction operating modes, making it the ideal driver for differential drive (tank style) robots and more.

The operating mode is set with the onboard DIP switches so there are no jumpers to lose. Sabertooth features screw terminal connectors - making it possible for you to build a robot without even soldering.

Sabertooth is the first synchronous regenerative motor driver in its class. The regenerative topology means that your batteries get recharged whenever you command your robot to slow down or reverse. Sabertooth also allows you to make very fast stops and reverses - giving your robot a quick and nimble edge.

Sabertooth has a built in 5V BEC that can provide power to a microcontroller or R/C receiver. The lithium cutoff mode allows Sabertooth to operate safely with lithium ion and lithium polymer battery packs - the highest energy density batteries available.

Sabertooth's transistors are switched at ultrasonic speeds (32kHz) for silent operation.

Sabertooth 2X25 uses 1.3 milliohm MOSFETs in its bridge. Going by other's ridiculous rating schemes this would make it a dual 190A motor driver!

Model: Sabertooth 2X25
Specifications: 25A continuous, 50A peak per channel.

Synchronous regenerative drive
Ultra-sonic switching frequency
Thermal and overcurrent protection
Lithium protection mode

Input modes: Analog, R/C, simplified serial, packetized serial

Size: 2.6” x 3.2” x .8”
65 x 80 x 20 mm

Weight: 96g / 3.5oz

Applications: Combat robots up to 100lb
Normal and hobby robots up to 300lb
Differential drive robots
Electric vehicles, ride-on toys, scooters
Easy speed/direction control for pumps, conveyors, automation and any application that uses two brushed DC motors

For more even more about the Sabertooth, you can go here and here

I have uploaded some information about the Sabertooth, including the manuals, so it doesn't vanish like so many things on the web do...

Sabertooth 2x25 QuickStart.doc
Sabertooth 2x25 QuickStart.pdf
Sabertooth 2x25 Manual.doc
Sabertooth 2x25 Manual.pdf
Motor Drive Efficiency Comparison Test.pdf

Tuesday, 8 July 2008

Knight Rider

I have received a message that the "Knight Rider" LED kits are ready for me to pick up. I am going to that today at lunch from Active Electronics in town.

This morning I ordered my motor controller. There will probably be a customs delay of a weeks or two, but shouldn't be too much longer than that. I am getting a Sabertooth dual 25A motor driver from Robot Parts, an Australian online store for robot parts funnily enough.