Download Microstepping Driver - AV-iQ

Motion Control
SMD 703
24~60V, 0.75~3.6A
Microstepping Driver
SMD 707
24~60V, 1.5~7A
Microstepping Driver
USER’S MANUAL
REVISION 1.0 – 2001
No part of this manual may be reproduced without permission.
CyberResearch, Inc.
www.cyberresearch.com
25 Business Park Drive, Branford, CT 06405 USA
203-483-8815 (9am to 5pm EST) FAX: 203-483-9024
©1994 CBI ©1997 CyberResearch, Inc.
©Copyright 2001 CyberResearch, Inc.
All Rights Reserved.
Revision 1: 2001
The information in this document is subject to change without prior notice in order to
improve reliability, design, and function and does not represent a commitment on the
part of CyberResearch, Inc.
In no event will CyberResearch, Inc. be liable for direct, indirect, special, incidental, or
consequential damages arising out of the use of or inability to use the product or
documentation, even if advised of the possibility of such damages.
This document contains proprietary information protected by copyright. All rights are
reserved. No part of this manual may be reproduced by any mechanical, electronic,
or other means in any form without prior written permission of CyberResearch, Inc.
TRADEMARKS
“CyberResearch,” “SMD 703,” and “SMD 707” are trademarks of CyberResearch, Inc.
Other product names mentioned herein are used for identification purposes only and
may be trademarks and/or registered trademarks of their respective companies.
• NOTICE •
CyberResearch, Inc. does not authorize any CyberResearch product for use in life
support systems, medical equipment, and/or medical devices without the written
approval of the President of CyberResearch, Inc. Life support devices and systems
are devices or systems which are intended for surgical implantation into the body, or
to support or sustain life and whose failure to perform can be reasonably expected to
result in injury. Other medical equipment includes devices used for monitoring, data
acquisition, modification, or notification purposes in relation to to life support, life
sustaining, or vital statistic recording. CyberResearch products are not designed with
the components required, are not subject to the testing required, and are not submitted
to the certification required to ensure a level of reliability appropriate for the treatment
and diagnosis of humans.
CONTENTS
General Description.......................................................1
Connector Description...................................................3
Power Supply Requirements .......................................3
Fuse............................................................................3
Motor Output..............................................................4
Motor Wiring...............................................................5
Series Wired................................................................5
Parallel Wired .............................................................5
Motor Wire Color Codes ..............................................6
Noise Precautions .......................................................7
Direction and Step Inputs...........................................7
Current Set.................................................................8
Default Current ..........................................................9
Standby Implementation ............................................9
Microstepping ................................................................11
Factors Affecting Microstep Accuracy ............................12
Motor Accuracy...........................................................12
Motor Linearity ...........................................................12
Motor Load .................................................................13
Anti-Resonance Circuit..................................................13
Disadvantages ............................................................15
Performance Considerations..........................................16
Torque and Power vs. Speed .......................................16
Factors Affecting Power and Torque............................17
Power Supply Voltage .................................................17
Series vs. Parallel Operation .......................................18
Torque ........................................................................19
Power Supply Current ................................................20
Heating Considerations ..............................................21
Motor Speed-Torque and Speed Power Curves ..............22
Specifications ................................................................30
GENERAL DESCRIPTION:
CyberResearch's's SMD 703 and SMD 707 are step motor drives
whose major features are microstepping and anti-resonance
circuitry. These compensate for low speed vibration and
mid-band instability respectively.
The SMD 707 is designed to run unipolar hybrid PM step
motors with current ratings from .75 to 7 amps per phase;
the SMD 703 is designed to work with motors rated at 1.5 to
14 amps per phase.
The control interface for these drives is opto-isolated for
maximum noise immunity. The inputs are directly compatible
with TTL drivers and do not require additional components.
The drives require a single voltage, unregulated DC power
supply between 24 VDC and 60 VDC. The power supply current
requirements are very modest. For 6 wire step motors wired in the
series configuration, the power supply current is approximately
1/3 of the motor's rated per phase current.
A high efficiency switching 'H' bridge output utilizes power
MOSFETS to keep heating to a minimum. Under most conditions
the drives will not require heat sinking. It is sufficient to bolt
them down to a metal chassis in the user's system.
The drives are small; measuring 4" x 4.5" x .8" and weighing only
1.2 lb. They come encapsulated in a heat conductive epoxy and
encased in an anodized aluminum outer cover. The result is a
compact environmentally rugged package that resists abuse that
would destroy most other controls.
-1-
WARNER SM-200-0125-BC
200
175
150
125
100
TORQUE
(OZ/IN)
75
0K
1K
2K
3K
4K
81
73
71
67
60
0
16
31
45
53
5K
6K
7K
8K
9K
10K
65
69
66
67
67
68
72
92
106
126
133
152
50
25
POWER
(WATTS)
1K
2K
200
175
150
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
MAE MY200-2240-460A8
TORQUE
(OZ/IN)
125
100
10K
9K
0K
1K
2K
3K
4K
5K
6K
145
144
138
139
124
113
99
0
31
61
92
109
125
132
7K
8K
9K
10K
86
74
67
59
134
132
133
131
75
50
POWER
(WATTS)
25
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
CyberResearch's SMD 703 MICROSTEP DRIVE
(Actual Size)
-2-
10K
CONNECTOR DESCRIPTION:
TERMINAL 1,2 POWER SUPPLY
Terminal 1 (internally connected to Terminal 12) is the power
supply return or ground connection. Terminal 2 is the positive
power supply input connection. The power supply voltage range is
from 24 VDC to 60 VDC. The power supply need not be regulated;
however if an unregulated power supply is used, care must be
taken to insure that the power supply ripple and line voltage
tolerance do not exceed this specified supply voltage range. The
recommended power supply ripple voltage is 1 volt peak to peak
or less for best performance.
Power supply current may be estimated for a 6 wire motor as 1/3
of the motor's per phase current rating for series operation (fig. 3).
For parallel operation (fig. 4), use 2/3 of motor's per phase
current rating for estimating supply current. At light loads and
medium speeds considerably less current is needed.
See 'PERFORMANCE CONSIDERATIONS' (page 16) for more
information about the selection of an appropriate power supply
voltage and motor operating mode.
WARNING!
ALWAYS DISCONNECT POWER TO THE DRIVE BEFORE
EITHER CONNECTING OR DISCONNECTING ANY MOTOR
LEADS. FAILURE TO DO THIS WILL RESULT IN IRREPARABLE
DAMAGE TO THE DRIVE.
During rapid deceleration of large inertial loads, step motors
generate considerable power. This power is returned to the power
supply by the step motor drive. Usually the filter capacitor in the
power supply is sufficient to absorb this power safely and keep
the voltage rise to acceptable limits. If the power supply cannot
absorb this power, the voltage generated may exceed the 60 VDC
limit of the drive. Damage may result to the control, power
supply, or both. In this rare instance, an external voltage clamp,
such as a 68 volt zener diode, is recommended as protection.
For protection against motor to ground shorts, power supply
voltage reversal and other anomalies, use a 5 AMP fuse from the
power supply to TERMINAL 2.
EXAMPLE:
Design an unregulated power supply for use with a SUPERIOR
ELECTRIC M092 FD04. Series operation at 35 VDC will be used.
-3-
D 1-4
+VDC
T1
115 V
C1
Figure 1
1. The M092 FD04 has a current rating of 4 Amps per phase.
Because series operation is to be used, power supply current
will not exceed:
Isupply = IM/3 = 4/3 = 1.33 AMPS
2. For a ripple voltage of 1 volt or less, the minimum capacitor
(C1) size is:
C1 = Isupply x 8333 = 1.33 x 8333 = 11,000 MFD
3. The transformer (T1) secondary voltage is going to be:
VRMS = Vsupply x .7071 = 35 x .7071 = 25 VAC
The secondary current rating should be at least 1.5 AMPS.
TERMINAL 3,4,5,6
MOTOR OUTPUT
One motor winding connects to terminals 3 and 4, while the
other winding connects to terminals 5 and 6. The step motor drive
will operate 4,6 and 8 wire motors. The 6 and 8 wire motors may
be wired in either a series or parallel configuration. For 8 wire
motors, follow the manufacturer's hook-up diagrams for series or
parallel operation.
WARNING!
BEFORE EITHER CONNECTING OR DISCONNECTING ANY
MOTOR LEADS, ALWAYS DISCONNECT THE POWER FIRST.IF
THIS IS NOT DONE, THE DRIVE WILL BE PERMANENTLY
DAMAGED.
The most common step motor has 6 lead wires, which connect
to a pair of center-tapped windings. A typical 6 wire motor is
shown below (fig. 2). The SUPERIOR ELECTRIC color code is used
in this example.
-4-
RED
BLACK
RED/WHT
GREEN
WHITE
GRN/WHT
Figure 2
SERIES WIRED
RED
(Pin 5)
NC
RED/WHT
(Pin 6)
NC
GRN/WHT
(Pin 3)
GREEN
(Pin 4)
Figure 3
PARALLEL WIRED
RED
(Pin 5)
BLACK
(Pin 6)
NC
NC
GREEN
(Pin 4)
WHITE
(Pin 3)
Figure 4
-5-
Parallel wired step motors have twice the peak shaft power as
series wired step motors. Parallel wired step motors also have
more that twice as much heat dissipation as do series wired
motors. For a more thorough discussion see the 'PERFORMANCE
CONSIDERATIONS' section starting on page 16.
When using the series configuration, select the appropriate
current set resistor from the CURRENT SET RESISTOR TABLE.
When using the parallel configuration, or a 4 wire motor, make
the selection from the 'PARALLEL' column.
The proper motor wire color code to drive connector hook-up
for series and parallel operation is shown in the tables below.
This hook-up will yield clockwise motor rotation when the
DIRECTION input is at a logical '0'.
TABLE 1
SERIES WIRED
Manufacturer
T3
T4
T5
Superior Electric
Rapidsyn
Imc
Sigma
Oriental Motor
Portescap
Bodine
Digital Motor
Warner
Japan Servo
Grn/Wht
Grn/Wht
Grn/Wht
Yellow
Blue
Yel/Wht
Yellow
Yellow
Red
Yellow
TABLE 2
Manufacturer
Superior Electric
Rapidsyn
Imc
Sigma
Oriental Motor
Portescap
Bodine
Digital Motor
Warner
Japan Servo
T3
Green
Green
Green
Red
Red
Red
Red
Red
Yellow
Green
Red
Red
Red
Black
Black
Org/wht
Brown
Black
Orange
Blue
PARALLEL WIRED
T4
T5
White
White
White
Red/Yel
Blue
Yel/Wht
Red/Wht
Red/Wht
Red
White
-6-
Green
Green
Green
Red
White
Red
Red
Red
White
Green
Red
Red
Red
Org/Blk
Yellow
Org/wht
Org/wht
Black
Orange
Blue
T6
Red/Wht
Red/Wht
Red/Wht
Orange
Green
Brown
Orange
Orange
Brown
Red
T6
Black
Black
Black
Orange
Green
Brown
Orange
Blk/Wht
Black
White
Under some conditions the unused wires may have voltages in
excess of 120 volts. Consequently all motor wires not used should
be insulated and not allowed to touch anything.
The SMD 703/707 are high frequency switching type drives.
Because of the power involved and the rapid rate of current
and voltage change inherent in this type of control, considerable
RFI is generated. The following precautions must be taken
to prevent this noise from coupling back to the inputs and
causing erratic operation.
1. Never bundle the motor leads in the same cable as the STEP
and DIRECTION input leads.
2. Always keep power supply leads as short as possible. If this is
impractical, use .1 µF and 100 µF capacitors directly
across TERMINALS 1 and 2 at the step motor drive.
3. Never wire capacitors, inductors or any other components to
the motor output terminals.
4. Always ground the chassis that the step motor drive is
mounted on.
5. Always ground the motor case.
6. Never use op amps, optocouplers or other slow transitioning
devices to drive the STEP input. Keep the logic transitions to
200 nSec. or less.
TERMINAL 7 NO CONNECTION (SMD 703/707)
On the SMD 703/707 microstep drives this terminal is
reserved for future use. Do not connect.
TERMINAL 8,9,10 DIRECTION AND STEP INPUTS
Terminal 8 is 'DIRECTION' input. A low level on this terminal
will result in a clockwise microstep when the 'STEP' input is
pulsed on a SMD 703 or SMD 707 microstep drive.
Terminal 9 is the 'STEP' input. A step occurs on the
high to low transition of the 'STEP' input, the direction being set
by the level on the 'DIRECTION' input at that moment. Terminal
10 is the '+5 VOLT' common to terminal 8 and 9.
-7-
The DIRECTION and STEP inputs are optically isolated from
the rest of the step motor drive circuitry. The isolated inputs are
intended to be driven directly by standard TTL or open collector
outputs. Because TTL is current sink logic, the driver 5 VDC
power supply must be connected to terminal 10, '+5 VOLT'.
Both the DIRECTION and STEP inputs require 16 mA current
sink capability. The logic transition time for the STEP input must
be 200 nanoseconds or less. The minimum pulse width for the
STEP input is 1 microsecond. The maximum pulse rate is 1 Mhz
when a 50% duty cycle square wave is used.
TERMINAL 11,12
CURRENT SET
The primary function of the CURRENT SET terminal is to set
the magnitude of the motor phase currents. This is done by
connecting a 1/4 watt resistor between terminals 11 and 12. The
correct resistor value in ohms is chosen from the tables below.
For convenience the appropriate table is also printed on the face
of the step motor drive. If a 6 wire motor is to be series connected,
use the first column, otherwise use the second column for parallel
connected motors.
Match the motor's per phase current to the closest listed table
entry, then pick the resistor associated with that current.
TABLE 3
SMD 707 CURRENT SET RESISTOR TABLE
SERIES
PARALLEL
RESISTOR
1.5A
2.0A
2.5A
3.0A
3.5A
4.0A
4.5A
5.0A
5.5A
6.0A
6.5A
7.0A
.75A
1.00A
1.25A
1.50A
1.75A
2.00A
2.25A
2.50A
2.75A
3.00A
3.25A
3.50A
12K
15K
27K
33K
47K
68K
82K
120K
180K
270K
560K
3.3M
-8-
TABLE 4
SMD 703 CURRENT SET RESISTOR TABLE
SERIES
PARALLEL
RESISTOR
3.0A
4.0A
5.0A
6.0A
7.0A
8.0A
9.0A
10.0A
11.0A
12.0A
13.0A
14.0A
1.5A
2.0A
2.5A
3.0A
3.5A
4.0A
4.5A
5.0A
5.5A
6.0A
6.5A
7.0A
12K
15K
27K
33K
47K
68K
82K
120K
180K
270K
560K
3.3M
CAUTION:
Without a current set resistor present, the SMD 707 and
the SMD 703 default to 3.6 amp and 7.2 amp drive currents
respectively. If these current levels are in excess of a motor's
rated per phase current, they may damage the motor.
For good low-speed smoothness with the SMD 703/707, the
motor set current should not vary more than ±20% from the
nominal value. This is because accurate microstep spacing occurs
over a narrow range of currents. Currents substantially above or
below this range may reduce microstep positioning accuracy and
increase low speed vibration.
The CURRENT SET terminal has a secondary function. One
optional use for the CURRENT SET input is to set a lower standby
current while the motor is stopped, or shut off motor current
altogether. A standby current can be set by switching another
resistor in parallel with the current set resistor. The standby
current will be equivalent to the resulting parallel wired resistor.
If the current set resistor is shorted out, motor current goes to
zero, and the motor is freewheeling.
Fig. 5 shows how an optically isolated standby torque and
freewheeling functions may be implemented.
-9-
STAND BY
+ 5 VD C
C UR RE N T
SET
R ES I S TO R
4N28
TTL
220
TTL
220
4N28
' 0 ' = RU N
' 1 ' = S TA ND B Y
' 0' = ON
' 1 ' = R ES E T
Figure 5
WARNING!
NEVER CONNECT OR DISCONNECT ANY OF THE MOTOR
LEADS WITHOUT FIRST DISCONNECTING THE POWER. IF
POWER IS NOT TURNED OFF BEFORE ATTACHING OR
REMOVING THE MOTOR WIRES, THE DRIVE WILL BE
DAMAGED BEYOND REPAIR.
- 10 -
11
12
MICROSTEPPING:
Microstepping is a technique that electronically multiplies the
number of steps a motor takes per revolution. This is useful
because it increases motor angular resolution and decreases
motor vibration.
The multiplier is 10 for the SMD 707 and the SMD 703.
Thus a 200 step per revolution motor, when driven by this
control, will take 2000 steps to complete one revolution.
Microstepping is accomplished by driving the motor windings
with sine and cosine weighted currents. A 90 degree electrical
angle change in these currents results in a mechanical angle
change of 1.8 degrees in a 200 step motor, or one full step.
The number of microsteps per step is determined by the
number of sine and cosine values stored for a span of 90 degrees.
In the SMD 703/707, values are stored for every 9 electrical
degrees for a total of 10 for the 90 degree span.
A counter in the SMD 703/707 addresses a look-up table
that contains pre-calculated sine and cosine values. These values
are multiplied by a value proportional to the motor's rated current
(determined by the current set resistor). The results are converted
to phase currents and applied to the motor.
The STEP input, in conjunction with the DIRECTION input,
increments or decrements this counter, which then selects the
next look-up table entry.
Low speed vibration results from the start-stop or incremental
motion of the motor. This generates periodic acceleration and
deceleration reaction torques at the step rate. When the step rate
matches, or is a sub-harmonic of the mechanical resonant
frequency of the motor, the vibrations become particularly severe.
Microstepping decreases the magnitude of each step ten-fold,
with a commensurate decrease in vibration. Vibration is further
reduced because at any given speed the microstep rate is 10
times higher than the equivalent full step rate.
One apparent benefit of microstepping is an increase in the
number of resolvable angular positions. However, there are a
number of factors which limit its achievable open-loop accuracy.
- 11 -
FACTORS AFFECTING MICROSTEP ACCURACY
MOTOR ACCURACY:
Most step motors are specified as having a ± 5% nonaccumulative step tolerance. This implies that a 200 step per
revolution motor will have an absolute accuracy of 1 part out of
2000.
If the motor were run open-loop (as most step motors are) only
a ten-fold increase in accurately resolvable locations can be
expected. Consequently a 125 microstep drive cannot position a
motor any more accurately than a 10 microstep drive, such as the
SMD 703/707, in an open-loop configuration.
MOTOR LINEARITY:
For every motor there is a function that relates the angle of
rotation to the electrical angle of the winding currents. If it were
directly proportional, then sine and cosine varying currents would
cause a uniform rate of rotation. Alternately this would result in
uniformly spaced microsteps.
- 90 O
E LE C T RIC AL A NG L E
+9 0 O
For most motors this function is 'S' shaped to a greater or
lesser degree (fig. 6). The motor current profiles must be distorted
from their ideal sine-cosine profiles to compensate for this nonlinearity. How well this compensates for the motor's non-linearity
will determine the microstep placement accuracy of the control.
- 1 .8 O
0
M ECH AN ICA L AN GL E
Figure 6
- 12 -
+ 1 .8
O
The electrical to mechanical angle function is dependent on
motor current. By varying the current set resistor value, it may be
possible to trim out any residual positional error. Should this be
insufficient.
MOTOR LOAD:
A step motor only generates torque when a rotor error angle
exists. The relationship between rotor displacement angle and
restoring torque for a typical motor is shown in fig. 7.
-3 00
TOR QU E (O Z-I N)
+3 00
The function that relates error angle to torque is approximately
sinusoidal, so an error angle equal to one microstep occurs with
torque load of only 16% of holding torque. Generally speaking,
motor load is the single most significant contributor to microstep
positioning error. If the load is transient or due to acceleration,
the rotor error will decrease to a residual level upon removal of
that transient.
-1. 8
O
0
+ 1. 8
O
ME C HA NI CA L A NG LE
Figure 7
ANTI-RESONANCE CIRCUIT:
Most step motors are prone to parametric instability or
resonance when rotating between 4 to 15 revolutions per second.
Variously called midband instability, resonance or other terms, it
manifests itself as a torsional oscillation of 50 to 150 Hz when the
motor is running in this speed range. The torsional oscillation has
a tendency to increase in amplitude with time until it reaches a
peak equal to the step angle. When this happens, the motor loses
synchronization and stops.
- 13 -
Generally the amplitude build-up takes from tens to hundreds
of cycles to reach this level, so up to several seconds may elapse
from the start of the oscillation until the motor stops. This time is
sufficiently long to permit the motor to accelerate through this
speed band, however continuous operation in this range is not
possible.
Above and below this range of speeds, the oscillation
amplitude may not be sufficient to stop the motor but it is still
present. Fig. 8 shows the parametric resonance frequency versus
motor step rate for three unrelated step motors. In all three cases
resonance breaks out at 5 to 7 revolutions per second and is most
severe at the higher torsional frequencies (lowest step rates).
S U PER IO R M0 62 -F D04
RE S ONA N T FR E QUE NC Y
150Hz
RA PI DS Y N 34 D -9 2 08 A
100Hz
50Hz
SI GM A 2 0 -2 23 50 - 281 75
5K H z
10KHz
1 .8 D E GRE E S TE P R AT E
Figure 8
Because any torsional oscillation implies acceleration and
deceleration of a mass, torque that otherwise would have been
available for useful work is wasted to sustain this oscillation.
Both the SMD 703 and the SMD 707 incorporate a midband
anti-resonance compensation circuit that closes the loop on
this instability and electronically damps it out. Since the motor
is now unable to sustain oscillation, torque previously wasted
is now available.
- 14 -
With anti-resonance the motor may be run continuously at
speeds where de-synchronization would otherwise occur. The
motor no longer exhibits 'forbidden' continuous-operation speed
bands and there is more torque available outside these speed
ranges as well.
The operation of the anti-resonance circuit in most
applications is transparent to the user, in the sense that no
special provisions have to be taken to accommodate it. There are
three instances where it may be disadvantageous:
1. VERY HIGH SPEED
The anti-resonance circuit limits the maximum speed to
30,000 full steps per second (300,000 pulses per second).
Should it be necessary to run the motor faster than that, up
to 100,000 full steps per second, a special "anti-resonance
disabled" version of the step motor drive can be ordered (a
SUPERIOR ELECTRIC ME61-8001 will exceed 100,000 full
step per second or 30,000 RPM).
2. VERY LARGE INERTIAL LOAD
Microstepping permits reliable operation with inertial
loads in excess of 100 times the motor's moment of inertia.
However a very large inertial load so lowers the mechanical
resonant frequency that the anti-resonance circuit may cause
oscillation. It may be better to order the drive without the
circuit since resonance usually is not a problem with
moderate to large inertial loads anyway.
3. IRREGULAR PULSE TRAIN
To operate properly, the anti-resonance circuit cannot
tolorate more than a 15% variation in the pulse period at the
STEP input. Any variation in excess of this limit may result in
missed steps. There are some digital pulse sources that have
more than a 15% period to period variation. To use these
sources without error the "anti-resonance disabled" version of
the step motor drive should be ordered.
- 15 -
PERFORMANCE CONSIDERATIONS
This section will deal with factors that affect motor
performance and the interactions between these factors. This
should permit the designer to achieve the optimum balance of
performance trade-offs. The factors considered will be:
TORQUE
OUTPUT POWER
POWER SUPPLY VOLTAGE
SERIES vs. PARALLEL OPERATION
POWER SUPPLY CURRENT
MOTOR HEATING
MOTOR DRIVE HEATING
TORQUE AND POWER vs. SPEED:
Step motor performance curves exhibit two distinct regions
with respect to speed. In region 1 (fig. 9), motor torque is constant
with speed while motor shaft power is proportional to speed. In
region 2, motor torque decreases as the inverse of the speed while
motor shaft power remains constant.
400
350
REGION 1
REGION 2
300
TORQUE
(OZ/IN)
TORQUE
250
200
150
POWER
100
POWER
(WATTS)
50
0
1K
2K
3K
4K
5K
6K
7K
FULL STEPS PER SECOND
Figure 9
- 16 -
8K
9K
10K
In region 1 the motor torque is held constant by controlling the
magnitude of the motor phase current. The step rate in this
region is sufficiently low to permit motor current to reach the
programmed value.
Above a certain speed, the motor torque begins to drop off as
the inverse of the speed. Motor winding inductance limits the rate
of current rise, and as speed increases, progressively less current
can be forced into the windings. Because motor torque is
proportional to phase current, and in region 2 current is
proportional to the step period, torque decreases as the inverse of
the step rate.
Because power is the product of speed and torque, power
remains constant with speed in region 2 in a loss-less step motor.
There are speed related power losses in the motor ( i.e. friction,
magnetic losses, windage and other losses ) that result in a
shallow slope to the power curve. Where this slope intersects the
speed axis is the maximum speed at which the motor will run.
CAUTION:
The SMD 703/707 drive is capable of running step motors at
speeds high enough to cause damage to motor bearings.
FACTORS AFFECTING POWER AND TORQUE
POWER SUPPLY VOLTAGE:
The choice of power supply voltage affects the power a step
motor generates in region 2. The speed to which constant torque
is maintained is proportional to power supply voltage.
Consequently maximum motor shaft power is also proportional to
the power supply voltage.
The step motor drive has a power supply range from 24 to 60
VDC. This results in a motor power range of 2.5:1.
Increasing power supply voltage increases motor heating.
Taking this into consideration, the choice of power supply voltage
should be just high enough to meet the application's power
requirements and no higher.
- 17 -
SERIES vs. PARALLEL OPERATION:
The customer has the option of wiring 6 and 8 wire motors in
either series or parallel configuration.
Parallel operation doubles the maximum motor power output
over what can be obtained with series operation. The speed to
which constant torque is maintained is also doubled. This
performance improvement comes at the expense of greater motor
and control heating.
Series operation is preferred for low speed (region 1) operation,
and suitable in region 2 if the available power is sufficient. Series
operation benefits are low motor and control heating and modest
power supply current requirements.
Using the power supply voltage range in conjunction with
either series or parallel operation permits a 5:1 range in
maximum motor power.
Fig. 10 illustrates the effects of series vs. parallel operation at
low and high power supply voltages on motor performance. Note
that series operation at 54 VDC supply voltage yields performance
virtually identical to parallel operation at 27 VDC supply voltage.
200
175
150
TOR Q U E
( O Z /I N )
125
T 1 ,P 1
T 2 ,P 2
T 3 ,P 3
T 4 ,P 4
T1
T2
T3
=
=
=
=
27
54
27
54
vo lts,
vo lts,
vo lts,
vo lts,
f u ll - w i n d in g
f u ll - w i n d in g
h a l f - w in d i n g
h a l f - w in d i n g
T4
P4 (105W)
100
75
P 2 (53 W )
50
P OW E R
( W AT T S )
P3 ( 50W)
25
P 1 ( 25 W)
1K
2K
3K
4K
5K
6K
7K
FU LL STEPS PER SECO ND
Figure 10
- 18 -
8K
9K
10K
TORQUE:
The current set resistor determines the motor torque in region
1. Motor torque is approximately proportional to motor current
times the number of winding turns that carry the current. In
series operation, twice the number of turns carry current as do in
parallel operation, so only half the current is needed to generate a
given level of torque.
Unfortunately series operation quadruples the effective
winding inductance. In region 2, motor power is proportional to
the inverse of the square root of the winding inductance.
Fig. 11 illustrates the effect of various winding currents on
motor performance. A 4 Amp per phase motor was driven from 1
to 6 Amps per phase in 1 Amp increments.
In region 1 motor torque is nearly proportional to motor
current. Torque remains constant until it intersects the motor's
load line, which may be approximated as:
T = kV / f L
T = torque
k = motor constant
f = steps per second
L = motor inductance
V = power supply voltage
The intersection of the constant torque line and the motor load
line marks the beginning of region 2. Above this speed motor
torque is not dependent on the current set resistor.
- 19 -
400
350
( 6 A /P HAS E )
300
( 5 A/ PHA SE )
TO RQU E
( OZ /IN ) 250
( 4 A /P HA SE )
( 3 A /P HA SE )
( 2 A/P HA SE )
200
(1 A /PHA S E)
150
100
POW ER
(WAT T S)
50
1K
2K
3K
4K
5K
6K
7K
8K
FULL STEP S PER SECO N D
9K
10K
SUPERIOR ELECTRIC M092-FD08
4A 3V
Figure 11
Note that if the motor in fig. 11 is operated in excess of 4000
steps/sec. it would make no performance difference what the
current set was. What would be significant would be the greatly
reduced motor and control heating at low speed at the lower
current setting.
POWER SUPPLY CURRENT:
Power supply current depends on the current set resistor
value, the speed the motor is running and the load applied to the
motor.
Generally speaking, the power supply current for a 6 wire
motor in the series configuration will not exceed 1/3 the motor's
rated per phase current. A parallel configured motor will require
no more than 2/3 the rated per phase current.
- 20 -
Fig. 12 is representative of a parallel configured motor's power
supply current requirements vs. speed. The solid curve is for an
unloaded motor while the dotted curve is for a fully loaded motor.
SUPERIOR M062-FD04
SMD 707
PARALLEL WIRED 27V
POWER SUPPLY CURRENT
1.5A
1.0A
0.5A
0
10K
20K
FULL STEPS PER SECOND
Figure 12
MOTOR AND CONTROL HEATING:
Motor and control heating is equivalent to the difference
between the electrical power input and the motor's mechanical
power output. The ratio of the power out vs. power in is the
system efficiency.
The power losses are dependent on motor speed, load and
winding configuration, the power supply voltage, current set and
other factors.
The power losses in the step motor drive are primarily resistive
and therefore relatively easy to calculate. Each channel of the
drive may be considered to be equivalent to a .55 ohm resistor.
WARNING!
THE DRIVE MUST HAVE SUFFICIENT HEAT SINKING TO KEEP
THE CASE TEMPERATURE BELOW +75 DEGREES C (+167
DEGREES F) OR PERMANENT DAMAGE WILL RESULT.
- 21 -
Step motor drive dissipation in region 1 is always considerably
higher than in region 2. In region 1, motor phase currents, and
therefore drive channel currents are sinusoidal. The peak
amplitude is equal to the rated per phase current in the parallel
mode and half of that in the series mode. In region 1, power
dissipation is approximately:
W = .55 (Iφ)2
W = .55 (Iφ/2)2
for parallel wired motors
for series wired motors
Note that the power dissipation is 4 times higher for the parallel
connection.
In region 2 power dissipation can be calculated as:
W = 1.1 (Iφ/3)2
W = 1.1 (Iφ/6)2
for parallel wired motors
for series wired motors
Region 1 power dissipation is 4.5 times greater than region 2
power dissipation. If the motor will spend most of its time stopped
or in region 1, use region 1 power dissipation equations to
evaluate the needs for heat sinking. Alternately, consider
reducing motor set current while the motor is stopped to reduce
power dissipation. As a practical guide, heat sinking will almost
certainly be required if the drive is set to 3 amps or more.
Generally, if the unit is too hot to touch, it needs additional
cooling. The case temperature should never under any
circumstance, be allowed to exceed +75 degrees C (+167 degrees
F), since this will destroy the drive.
MOTOR SPEED-TORQUE & SPEED-POWER CURVES:
The following pages contain motor speed-torque and speedpower curves. Two sets of curves are plotted per motor using the
SMD 703. One set was taken at 54 VDC power supply voltage, the
other at 27 VDC. The dynamometer moment of inertia was
adjusted to be equivalent to the motor's moment of inertia. The
test data was collected at 100 points between zero and 10,000 full
steps per second.
The motors were operated in the parallel configuration for both
test runs. The lower voltage test run is representative of a series
configured motor run at 54 VDC supply voltage. A power supply
voltage between the two test run voltages would yield results
between the plotted results. The dotted power output curve is the
mechanical power output of the motor, measured in watts.
- 22 -
SUPERIOR M093-FD14
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
TORQUE
(OZ/IN)
200
150
100
397
397
380
279
215
171
140
117
99
85
74
0
88
168
185
190
190
186
181
176
171
165
POWER
(WATTS)
50
1K
2K
400
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
RAPIDSYN 34D-9214R
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
9K
TORQUE
(OZ/IN)
200
224
213
204
195
163
137
118
99
87
76
67
10K
0
47
90
129
145
152
157
154
154
152
148
150
100
POWER
(WATTS)
50
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 23 -
7K
8K
9K
10K
WARNER SM-200-0125-BC
200
175
150
125
100
TORQUE
(OZ/IN)
75
0K
1K
2K
3K
4K
81
73
71
67
60
0
16
31
45
53
5K
6K
7K
8K
9K
10K
65
69
66
67
67
68
72
92
106
126
133
152
50
25
POWER
(WATTS)
1K
2K
200
175
150
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
MAE MY200-2240-460A8
9K
0K
1K
2K
3K
4K
5K
6K
TORQUE
(OZ/IN)
125
7K
8K
9K
10K
100
10K
145
0
144
31
138
61
139
92
124 109
113 125
99 132
86
74
67
59
134
132
133
131
75
50
POWER
(WATTS)
25
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 24 -
7K
8K
9K
10K
MAE MY200-3437-400A8
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
TORQUE
(OZ/IN)
200
224
238
229
184
151
120
101
85
73
65
57
0
52
101
122
134
133
134
133
129
130
127
150
100
50
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
200
10K
SUPERIOR M093-FD11
400
250
9K
TORQUE
(OZ/IN)
397
397
294
199
149
117
93
78
63
53
45
0
88
130
132
132
129
124
120
113
105
100
150
POWER
100 (WATTS)
50
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 25 -
7K
8K
9K
10K
BODINE 34T3 2005
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
TORQUE
(OZ/IN)
368
346
277
188
141
113
93
76
65
56
48
0
76
123
125
125
126
124
118
116
111
107
150
100
POWER
(WATTS)
50
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
JAPAN SERVO KP88M2-001
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200 TORQUE
397
397
269
188
135
107
87
73
60
51
43
0
88
119
125
120
119
116
113
107
102
96
(OZ/IN)
150
POWER
100 (WATTS)
50
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 26 -
7K
8K
9K
10K
RAPIDSYN 34D-9206A
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
150
100
50
246
234
213
156
121
98
81
67
57
49
43
0
51
94
103
107
108
107
104
102
99
96
TORQUE
(OZ/IN)
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
VEXTA PH265-05
200
46
0
39
8
36
16
35
23
39
35
43
48
46
62
47
73
49
87
48
96
49 108
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
75
50
TORQUE
(OZ/IN)
25 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 27 -
7K
8K
9K
10K
VEXTA PH296-01
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
150
151
141
140
135
113
93
81
68
57
49
43
0
31
62
90
100
103
107
106
102
99
96
TORQUE
(OZ/IN)
100
50
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
10K
BODINE 34T2 2104
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
9K
TORQUE
(OZ/IN)
250
200
0
262
54
248
94
213
159 105
118 105
93 103
99
74
94
60
88
49
83
42
79
35
150
100
50
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 28 -
7K
8K
9K
10K
SUPERIOR M092-FD08
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
150
100
294
0
283 62
219 97
156 103
113 100
92 101
74 99
62 96
51 91
43 87
37 82
TORQUE
(OZ/IN)
POWER
(WATTS)
50
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
SUPERIOR ME61FD-80083
200
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
74
70
65
65
67
68
64
60
54
49
44
0
15
29
43
59
76
86
94
96
97
98
75
50
25
TORQUE
(OZ/IN)
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 29 -
7K
8K
9K
10K
JAPAN SERVO KPM8AM2-001
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
224
212
198
143
109
85
70
57
48
42
37
0
47
87
95
96
95
93
89
85
83
82
200
TORQUE
150 (OZ/IN)
100
POWER
50 (WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
50
25
10K
VEXTA PH268-05
200
75
9K
78
75
70
71
71
73
67
60
53
46
40
0
16
31
47
63
81
89
94
95
93
89
TORQUE
(OZ/IN)
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 30 -
7K
8K
9K
10K
SUPERIOR M091-FD09
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
137
129
123
118
98
82
70
59
49
43
37
0
28
54
78
87
91
93
91
88
87
82
150
100
TORQUE
(OZ/IN)
50
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
SUPERIOR M061-FD08
200
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
48
44
39
36
39
43
44
43
43
42
40
0
9
17
24
35
48
59
67
77
85
89
75
TORQUE
50 (OZ/IN)
25 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 31 -
7K
8K
9K
10K
RAPIDSYN 23D-6306
200
150
125
147
138
129
120
101
77
65
53
46
37
30
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
TORQUE
(OZ/IN)
100
0
30
57
80
89
85
87
83
82
74
67
75
50
POWER
(WATTS)
25
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
RAPIDSYN 34-9601A
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
146
140
134
109
87
70
57
48
40
34
29
0
31
59
72
77
77
76
74
71
68
65
150
100
TORQUE
(OZ/IN)
POWER
50 (WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 32 -
7K
8K
9K
10K
SUPERIOR M091-FD-6006
400
0K 135
1K 131
2K 124
3K 98
4K 76
5K 63
6K 51
7K 43
8K 35
9K 31
10K 29
350
300
250
200
0
29
55
65
67
70
68
67
63
62
65
150
100 TORQUE
(OZ/IN)
50 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
VEXTA PH299-01
400
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
350
300
250
200
283
260
170
112
78
63
49
43
35
31
26
0
57
75
74
69
70
66
67
63
62
58
150
100
50
TORQUE
(OZ/IN)
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 33 -
7K
8K
9K
10K
RAPIDSYN 23D-6204
200
0K 106
1K 99
2K 93
3K 81
4K 64
5K 50
6K 42
7K 35
8K 29
9K 24
10K 21
175
150
125
100
0
21
41
53
57
56
55
54
52
49
46
TORQUE
75 (OZ/IN)
50
POWER
25 (WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
SUPERIOR M062-FD04
200
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
99
95
88
67
53
42
34
28
24
21
17
0
21
39
45
46
47
45
44
42
41
39
75 TORQUE
(OZ/IN)
50
25
POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 34 -
7K
8K
9K
10K
WARNER SM-200-0080-B8
200
59
56
53
53
44
36
28
23
19
17
0
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
0
12
23
35
39
40
37
36
34
34
0
75
50 TORQUE
(OZ/IN)
25 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
10K
0K 149
1K 131
2K
76
3K
51
4K
37
5K
26
6K
21
7K
17
8K
0
9K
0
10K
0
0
29
33
34
33
29
29
26
0
0
0
9K
10K
SUPERIOR M091-FD03
400
350
300
250
200
150
9K
TORQUE
(OZ/IN)
100
50 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 35 -
7K
8K
RAPIDSYN 23D-6102
200
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
63
56
55
47
36
28
22
18
0
0
0
0
12
24
31
32
31
30
29
0
0
0
75
50 TORQUE
(OZ/IN)
25 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
7K
8K
9K
10K
SUPERIOR M061-FD02
200
0K
1K
2K
3K
4K
5K
6K
7K
8K
9K
10K
175
150
125
100
63
59
50
35
28
21
17
0
0
0
0
0
13
22
23
24
23
23
0
0
0
0
75
50
TORQUE
(OZ/IN)
25 POWER
(WATTS)
1K
2K
3K
4K
5K
6K
FULL STEPS PER SECOND
- 36 -
7K
8K
9K
10K
SPECIFICATIONS
PARAMETER
MIN
MAX
UNITS
.1
.1
Full-step
24
50
18
.75
1.5
60
60
24
3.5
7.0
ELECTRICAL:
GENERAL
Resolution
SMD 703 & SMD 707
Supply voltage
Current (no motor)
PWM frequency
Motor current
SMD 707
SMD 703
Motor Inductance
1
STEP PULSE INPUT
Voltage
Input impedance
Pulse 'high'
Pulse 'low'
Rise time
Fall time
Frequency
Logic '1' volts
DIRECTION INPUT
Voltage
Current
Logic '1' volts
ENVIRONMENTAL:
Operating temp.
Humidity
Shock
Dust, oil, etc.
VDC
mA
kHz
ampere
ampere
mH
0
12
1
1
------+1.8
+5.0
20
----.5
.5
500
+2.0
VDC
mA
µSEC
µSEC
µSEC
µSEC
KHz
VDC
0
12
+1.8
+5.0
20
+2.0
VDC
mA
VDC
-20
+75
C
0
100
%
--150
G
---- NO LIMIT ----
MECHANICAL:
Weight
Size
Mounting hole centers
Mounting screw size
19
20
8h x 4w x 4.5d
3.625 x 3.625
#6
#8
- 37 -
OZ
inches
inches
- 38 -