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I have a circuit that consists of a torquer. Its torque is directly proportional to the current in the circuit. I want to precisely control the torque provided by the torquer and hence need to control the current in the circuit. Which is the best technique you would prefer using Arduino?

  • Depends on what you mean by "control current", what current and what voltage. – Milliways Dec 21 '16 at 5:31
  • @Milliways I have a constant voltage source and wish to control the current in the circuit with Arduino. Can it be done using PWM? – yobro97 Dec 21 '16 at 5:33
  • If you want any sensible answer you need the provide detail of what you are trying to control. – Milliways Dec 21 '16 at 5:37
  • @Milliways I have edited the question. I hope it has enough detail :) – yobro97 Dec 21 '16 at 5:43
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    Add a current sense resistor. Connect that to an analog pin so you can measure the current. Then change the PWM output value till the current is what you want it to be. Some people use a PID control loop for this. – Gerben Dec 21 '16 at 8:51
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The Arduino (like other microcontrollers) is a digital device. It doesn't "control current" on its own. It has outputs which can either be off or on. Off is 0V and on is 5V (assuming you are powering it from a 5V supply). The continuous current you can drawn from output pins is 20 mA.

You can use PWM to effectively reduce the power output (for example, a 50% duty cycle would be half on and half off, thus you would have 50% power).

If you drive your torquer from some sort of transistor (eg. a MOSFET) then PWM could conceivably achieve what you are wanting to do. A link to this device would be helpful. Plus, the other circuitry you have in mind.

  • Yes I have planned to include MOSFET switches. Could you provide details on how to do so? I am a beginner.... – yobro97 Dec 21 '16 at 6:07
  • @yobro97. Google "using MOSFET as a switch". – user31481 Jul 19 '17 at 9:57

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