quadrant control of DC Motors
Model 2748D Digital
Model 2748A Analog
10 Bit digitial input, or
±5 VDC analog input
1500 volt isolation (minimum)
Full-wave four-quadrant CD output
Opto-isolated failsafe input
||POWR UPS Model
2748A and 2748D motor controls are full wave, full regenerative (four
quadrant), completely self contained units that control the speed
and direction of motor torque of 24 VDC permanent magnet (PM) DC motors.
Direction switching is fully static (solid state). Model 2748 is an
exceptionally rugged unit that incorporates thyristor phase angle
control. Delivered output ranges to 2 amperes at 24 VDC. Less expensive
and more rugged than PWM servo amplifiers, these controls are ideal
for small velocity or position control applications, and replace costlier
and less rugged PWM amplifiers in many applications.
Model 2748 units are available in open frame construction, suitable
for OEM use in user provided enclosures. Power connections are made
using a heavy duty barrier block. Signal connections use a lighter
duty barrier block. Both blocks are field removable. Mounting holes
are provided for either bottom or edge mounting.
Model 2748 controls operate from a nominal 115 VAC, 60 Hz line. A
power line fuse is incorporated on the mounting base plate. These
controls are completely self contained and include an internal power
supply transformer to drive motors with an armature rating of 24 VDC.
ANALOG INPUT: Model 2748A analog input controls are designed
to be easily interfaced to low level analog circuitry. Signal input
signals are isolated from the motor and power line with a minimum
isolation voltage of 1500 VDC. This reduces the possibility of grounding,
noise or safety problems. The motor speed and direction are determined
by the amplitude and polarity (5 volts full scale) of the input signal.
In addition, a failsafe circuit de-energizes the motor if the input
control power is not present.
DIGITAL INPUT: Model 2748D digital input motor controls are
designed to be easily interfaced to microprocessors or 10 bit parallel
TTL logic level sources. Speed resolution is 9 bits, and one bit is
used for direction. For lower resolution, unused bits may be tied
off. Logic input signals are isolated from motor and power line with
a minimum isolation voltage of 1500 VDC. This reduces the possibility
of grounding, noise or safety problems. The motor speed and direction
are determined by the value of a ten bit parallel input which consists
of one bit for direction, and 9 bits for motor speed. In addition,
a failsafe circuit de-energizes the motor if the input control power
is not present.
Plug in adjustable Accel/Decel board permits clockwise and counterclockwise
control of acceleration and deceleration with four independent adjustments
Plug in optical encoder, electronic brake and Accel/decel board permits
four independent adjustments for high precision speed regulation,
electronic acceleration and deceleration.
Perforated metal cover (2748 COVER).