Unformatted text preview: section allow the controller to pulse-width modulate the
voltage supplied to a BDC motor. In terms of power
consumption, this method of speed control is a far more
efficient way to vary the speed of a BDC motor
compared to traditional analog control methods.
Traditional analog control required the addition of an
inefficient variable resistance in series with the motor.
BDC motors are driven in a variety of ways. In some
cases the motor only needs to spin in one direction.
Figure 6 and Figure 7 show circuits for driving a BDC
motor in one direction. The first is a low-side drive and
the second is a high-side drive. The advantage to using
the low-side drive is that a FET driver is not typically
needed. A FET driver is used to: 2.
3. bring the TTL signal driving a MOSFET to the
potential level of the supply voltage,
provide enough current to drive the MOSFET(1),
and provide level shifting in half-bridge
Note: The second point typically does not apply
to most PIC® microcontroller applications
because PIC MCU I/O pins can source 20
mA. 2010 Microchip Technology Inc. Motor R...
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- Winter '10
- Electric motor, BDC motors, bdc motor