2 thoughts on “Arduino Controlled ATX Power Supply

  1. servos shouldn’t need much current at all via a control pin, the "power" to their motors comes from dedicated power connectors, and the control pin switches that power to the motor on a little circuit board inside their cases. As such unless there’s a problem most of the current *should* be via servo’s power connections.

    Are you sure you understand how servos are instructed to move? Position of servo is controlled by duty cycle on the control pin. usually 50% equals mid position less equals change to a lesser angle, and more equals change to a greater angle . have a look at http://www.mcmanis.com/chuck/robotics/projects/servo.html which while for pic uC should give you the general idea/timings you’ll need.

    All a servo is a motor which always has a feedback mechanism to sense the angle the shaft has been rotated, and use that determine how a H-bridge should be controlled.
    References :

  2. What is the best way to control power to a servo using an Arduino?
    I’m playing around with some applications of servos (3-4) that will operate simultaneously from a single or multiple power sources and controlled independently with an Arduino. Unfortunately, I’ve discovered that Arduinos can’t exactly put out the amount of power required to drive multiple servos.

    I’m absolutely certain there’s a component to do what I need. I’ve heard a number of different terms but I’m not sure what exactly I’m looking for because I’ve never tried to do this before. Do I:

    – control current directly through a digital potentiometer?
    – use a voltage regulator?
    – use a breakout board intended for this application? If so, what’s the term I’m looking for?

    I’d rather have a completely controllable solution that I can scale up or down to fewer or more servos of various sizes and voltage requirements for the project I’m working on. I need to be able to control them all through an Arduino and I’d prefer to have them all run off of a single, rechargeable power source completely independent from the Arduino (and, ideally, a source that can charge the arduino when not powered via USB). I’d also like to add or remove servos and not have to alter the existing potentiometer/regulator/resistor setup of the previous servos.

    So, my question is, what are my options for how to connect an Arduino to multiple servos to utilize and control an external power supply?
    Also: would be helpful if this could also apply to DC motors.

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