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I am making a generator with a DC motor but the style of turning the rotor would be clockwise and then counter-clockwise, and I would want to capture as much current as possible so I hope it could be turned into AC current somehow. If so how?

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Well, if you reverse direction you will have an AC voltage at the motor terminals, frequency proportional to the period of reversal, peak amplitude proportional to peak shaft speed. It isn't necessarily sinusoidal unless the shaft speed is sinusoidally driven. This is assuming you are talking about a DC brush motor? A brushless DC motor will give you an AC voltage at the terminals if you drive it in either direction. Frequency and amplitude will be proportional to shaft speed.

I don't get the link between capturing as much "current" as possible and converting the output to an AC voltage, maybe you could explain a little more about what you are trying to accomplish?

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  • \$\begingroup\$ I am trying to harness the energy of a bolt (that I would attach the motor to) that spins rapidly clockwise and then changes direction and slowly spins counter clockwise back and then changes direction again and cycle repeats. \$\endgroup\$ Jul 6 '14 at 13:06
  • \$\begingroup\$ OK, that part is clear, but what are you trying to do with the output of the motor? Charge a battery? Just not clear on why you want AC vs. DC, since for most purposes you're just going to have to convert it to DC anyway. \$\endgroup\$
    – John D
    Jul 6 '14 at 19:09
  • \$\begingroup\$ yeah I am trying to charge a battery. But since the motor changes direction, I thought that that creates AC yet DC is needed for charging a battery. AC would be unpredictable I would think based on the inconsistency of the speed of the spinning bolt, which is why I asked, because rather than only getting DC when the motor is turned clockwise I thought it would be more efficient to get the current generated from clockwise spinning as well as counter-clockwise spinning in AC \$\endgroup\$ Jul 6 '14 at 20:52
  • \$\begingroup\$ I see- What you want to do is put a full-wave rectifier on the output to change the AC to DC, probably followed by a large electrolytic capacitor to smooth out the DC voltage. Then you have a shot at a stable DC source you can use to charge a battery. You could use a Schottky diode bridge for better efficiency if the output voltage of your motor isn't too high. \$\endgroup\$
    – John D
    Jul 6 '14 at 21:36

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