Servo motor H bridge control
Gerhard Fiedler email (remove spam text)
Bob Blick wrote:
> Locked Rotor (50% duty being zero) will give you the most accurate
> control, with the drawbacks being heat, power consumption, noise, and
> brush/commutator wear.
I'm not concerned about noise. Heat and power consumption I take it are
higher in (or close to) the 50% duty (motor standing), where the standard
configuration doesn't use any energy, but I'm able to switch it off
completely when it has reached that position.
What worries me is the wear. Is this also related mainly to the additional
wear in the 50% duty cycle situation? Or is the whole process of PWMing
between positive and negative polarity a stress on the brushes? How does
this compare to stopping or reversing direction by completely reversing the
current (like in the "normal" form of PWM driving)?
> If you have the luxury of disabling it most of the time, it may be just
> the thing for you. Otherwise it is likely to prove a headache in the
> long run.
It is my impression that most commercial servos use this form. Is this
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