STP DRVA RC 050 Regeneration Clamp Data Sheet Surestepclamp Datasheet

User Manual: STP-DRVA-RC-050 Regeneration Clamp Data Sheet SureStep™ Stepping Systems User Manual - AutomationDirect

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Data Sheet: STP-DRVA-RC_DS, 1st Edition – 10/2012 For a complete user manual, please visit www.automationdirect.com
STEPPING SYSTEMS
Sheet 1 of 2
STP-DRVA-RC-050 REGENERATION CLAMP
(FOR USE WITH 24–80 VDC POWERED STEPPER AND SERVO DRIVES)
DESCRIPTION
As with most stepper and servo systems, a clamp circuit is
required to limit increased power supply bus voltage when the
motor is decelerating under load. This is commonly referred to as
“regeneration,” which is what happens when DC motors are
driven by their load. During regeneration the DC motor can
produce enough voltage to actually exceed the input power
supply voltage. More sophisticated stepper and servo drives deal
with this by channeling the increased motor voltage back to the
source power supply. If the voltage is not clamped to a safe level
the amplifier can be damaged or destroyed.
For this reason AutomationDirect offers a “Regen Clamp” module
for our stepper/servo drive products. With this module one or
more stepper/servo drives can be protected from “Over Voltage”
conditions by placing the clamp module between the power
supply and the drive. The clamp tracks the input power supply
and will operate from 24 to 80 volts. No adjustments are needed.
The Regen Clamp is designed to handle a wide range of condi-
tions. The voltage input matches the needs of the SureStep
stepper drives and SureServo servo drives by providing 24 to 80
VDC capabilities. External power resistors, such as STP-DRVA-
BR-100, can be added for even greater continuous power require-
ments. The modules are small and compact to minimize impact
on the system design. More than one stepper/servo drive can be
connected to the clamp module, with the potential to handle an
entire multi-axis system.
FEATURES
The STP-DRVA-RC-050 Regen Clamp is mounted on a heat sink
and has a 50 watt power resistor for more continuous current
handling.
CIRCUIT DIAGRAM
The regeneration circuit is designed to provide a wide range of
voltage clamping operation with a simple and reliable design. The
block diagram gives a simplified view of the circuit design
showing the major parts.
TERMINAL BLOCK
A 6-connection terminal block provides easy connection access to
the clamp. The terminals are designed for wire sizes from 12–28
AWG.
INPUT DIODE
The input diode provides over-voltage and reverse-voltage protec-
tion. If the input power supply is connected in reverse, this diode
will prevent failure. During over-voltage conditions the diode
blocks the higher regeneration voltage from feeding into the input
power supply. The input is designed to handle 20 amps contin-
uous with peaks greater than 100 amps.
Clamp MOSFET
Over Voltage
Sense Circuit
Power
Resistor
Input Diode
Terminal Block
Vin
GND1
GND2
Vout
R1
R2
Green LED
Power Indication
Red LED
Clamp Indication
Sure
Step™ Regen Clamp Specifications
Part Number STP-DRVA-RC-050
Voltage Range 24 to 80 VDC, no user adjustments
Peak Power 800W
Continuous Power 50W
Connection 6-pin screw terminal block accepts 12–18 AWG wire
Indicators
Green LED: Indicates power supply voltage is present.
Red LED: Indicates that the clamp is operating.
(This is typically a very short time, since it is only on while
the stepper/servo is decelerating.)
Protection
The power supply is internally connected to an “Input Diode”
that protects it from higher regeneration voltages. The diode
protects the system from connecting the power supply in
reverse. If the clamp were to fail, the diode would continue to
protect the power supply from over-voltage.
Agency Approvals RoHS
INTERNAL POWER RESISTOR
For moderate power operation, this may be all that is required for
safe operation. This resistor is designed to “sink” up to 8 amps
when using an 80 volt power supply, but only 2.5 amps when
using a 24 volt supply.
Larger power resistors can be added to the circuit by connecting
between the “R1” and the “R2” terminals (STP-DRVA-BR-100).
FILTER CAPACITOR
A large capacitor is added across the voltage output to smooth
out operation and allow the “clamp” to work at a low switching
frequency.
OVER-VOLTAGE SENSE CIRCUIT
This part of the clamp senses when an over-voltage occurs.
The clamp will turn on when the “Vout” exceeds the “Vin” by
approximately 1.2 volts. The clamp turns off when “Vout” drops
to about 1 volt below “Vin”.
CLAMP MOSFET
At the heart of the circuit is a power MOSFET designed for
20-amp continuous operation
INDICATOR LEDS
A green LED is used to indicate power supply input, and a
red LED is used to indicate when the clamp is on.
EXAMPLE 1
A single stepper or servo drive is connected to the Regen Clamp
module. This design will work in most cases where the load is
primarily “Frictional,” as opposed to “Inertial.”
EXAMPLE 2
Two stepper or servo drives are connected to the Regen Clamp
module. This design will work in cases where the load has
significant “Inertial” content.
Regen Clamp
STP-DRVA-RC-050
24–65 VDC
Power
Supply
STP-DRV-6575
Drive #2
Resistor
STP-DRVA-BR-100
10Ω 100W
STP-DRV-6575
Drive #1
+
Vout
–
Vin
GND1
GND2
–
+
–
+
R1
R2
Regen Clamp
STP-DRVA-RC-050
24–65 VDC
Power
Supply
STP-DRV-6575
Drive #1
+
Vout
–
Vin
GND1
GND2
–
+
Data Sheet: STP-DRVA-RC_DS, 1st Edition – 10/2012 For a complete user manual, please visit www.automationdirect.com
STEPPING SYSTEMS
Sheet 2 of 2
STP-DRVA-RC-050 REGENERATION CLAMP
DIMENSIONS
STP-DRVA-RC-050
Dimensions = in[mm]
3.75
[95.3]
2.50
[63.5]
4.00
[101.6]
3.00
[76.2]
1.50
[38.1]
2.21
[56.2]
0.87
[22.1]
1.17
[29.7]
3X Ø0.12
[Ø3.0]
4X Ø0.12
[Ø3.0]
4-40 UNC
1.20
[30.6]
1.24
[31.5]
1.25
[31.8]
0.24
[6.1]
3.69
[93.7]
0.16
[4.0]

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