eovnu87435ds Posted August 12, 2010 Share Posted August 12, 2010 3 speed controllers in stock I have some Victor 884 Speed Controllers here for sale. These are made by the company IFI Robotics ( IFIrobotics.com ) and are the perfect controllers for all of your robotic needs. SPECS: These controllers have an input voltage range specified at 6v to 16v, however the internal components are rated to 25v. I have used some with a 24v input voltage with no problems whatsoever. Output voltage is 12v, and constant current is rated for 40 amps at 12v. You can use a standard computer jumper to set the controller from brake mode to coast mode. For those who don't know, if you have a motor spinning at full speed, and set it to neutral while on brake mode, the controller will actively stop the motors movement. This provides a method of braking, and can stop your robot incredibly fast. I've used these to stop a 500lb robot moving at 15 feet/sec in as little as 3 feet. The downsides to motor brakes are that it uses more power(which equals less battery runtime) and depending on the motor and your robot, it could potentially be damaging to your drivetrain. Coast mode, which is the default configuration with no jumper installed, means that it will coast to a stop when there is a neutral signal. The controller checks for brake settings 60 times a second, so you can even control it by remotely opening and closing the circuit. These controllers are also able to be calibrated, to ensure that in a project with more than one motor and speed controller, you will not have motors "fighting each other" PROGRAMMING: These are robotic speed controllers that use PWM to control, and are 100% Arduino compatible. You can use AnalogWrite(reccomended), or even just open up one of the servo examples. 255 is full speed forward, 0 is full speed reverse, and 127 is neutral/stop. Note, if using 2 controllers, one for each side of a robot, one of the motors have to spin in reverse to make the robot move foward. To slowly ramp up to a desired speed, use a for loop that will add 1-5 to a value. inside that loop, just have analogWrite(leftMotor,127 + forValue) and analogWrite(rightmotor,127 - forValue) MY REVIEW: I have used these in projects of all sorts of sizes, and have never found a need for a better controller. I've used them to power 280 sized motors in small RC vehicles, to a full sized remote controlled twin bed, with an all steel frame and capable of carrying two high school students while still reaching speeds of 15 feet/sec. Their durability and efficiency is unmatched in the world of robot motor controllers, and here I am letting go of some of my extras. PRICE: $40 shipped to upper 48 states. If you live in another country, AK, HI, or PR, feel free to PM me so we can work out a deal. I will be willing to do a partial or full trade for 240-pin DDR3 1333 desktop memory, if you have any extra modules lying around. PICTURES: Quote Link to comment Share on other sites More sharing options...
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