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PWM Modulator Circuit
发布日期:2008-5-14 12:52:17 文章来源:搜电 浏览次数: [pic]326
[pic][pic][pic]PWM Modulator Circuit
Servo motors (supplier, supplier, supplier) are relatively cheap and good
for positioning. They have a range of motion usually around 180 degrees--
they aren't used for continual rotation (though you can modify them for
this purpose). Servos combine a DC motor with a built-in gearbox and
feedback control loop. This means that once you set the proper position,
then even if you manually push the motor off equilibrium it will return to
it. How nice!
However, these servo motors are controlled by a Pulse Width Modulation
(PWM) signal. In other words, you send it a 50Hz square wave, but adjust
the width of the positive pulses between 0.5msec and 2.5msec to control
position. The