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New Size 20 Rotary Shaft Encoder from Quantum Devices October 8, 2014

Posted by Servo2Go.com in New Product Press Releases.
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Quantum Devices, Inc. model QDH20 provides an improved feedback solution in applications typically using a standard size 20 package.  The QDH20 provides encoder feedback in standard industrial mounting configurations with superb mechanical and environmental protection.

Outputs consist of a quadrature A & B with reference pulse Z as a standard feature.  The output can be configured with either the industrial standard 5 to 26 volt OL7272 line driver or open collector outputs.

Quantum QDH20 Encoder

Quantum QDH20 Encoder

The QDH20 features two heavy-duty bearing sets holding the output shaft, and two more bearings along with an integral flexible spring mount to isolate the working pieces of the encoder from mechanical stresses.

Features include:

  • 500 kHz Fundamental Frequency Response
  • High Operating Temperature Option (100 C)
  • Resolutions up to 5000 lines per revolution direct read
  • Flange and Servo Mount Options
  • 0.375″ shaft diameter
  • High Noise Immunity

 

More information on the QDH20 optical encoder from Quantum Devices can be found at the link below-

https://servo2go.com/product.php?ID=100132&cat=

For more information, please contact:

Editorial Contact:

Warren Osak
sales@servo2go.com
Toll Free Phone:  877-378-0240
Toll Free Fax:   877-378-0249
www.servo2go.com

 

Tags:  Encoder, Incremental Encoder, Single-Ended Encoder, Differential Encoder, Servo2Go, Quantum Devices

What is meant by Rotary Incremental Encoder Index Pulse “gating”? June 11, 2014

Posted by Servo2Go.com in Technical Support Information.
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Quantum Devices Optical Encoder

Quantum Devices Optical Encoder

Gating refers to the width of the Z (index) pulse relative to the A and B channels. With ungated devices the edges of the Z pulse have no hard relation to A & B.

Gating to channel A, requires the Z pulse to be high once per revolution and only when A is high.

Gating to channels A&B high requires the Z pulse to be high once per revolution and only when A AND B are high.

Gating to A creates a Z pulse roughly 180 Electrical Degrees in duration while gating to A&B creates a Z pulse roughly 90 Electrical Degrees in duration.

Gating to a smaller duration increases the precision of the Z pulse, but also requires the motion system to be able to read the Z channel at a faster rate.

Gating is sometimes required by certain drive/amplifier/controller manufacturers.

QD145 Z (Index Pulse) Specifications:

incremental-encoder-gating1
Ungated Z
Z-A/A-Z min = 0 Electrical Degrees
Z-A/A-Z max= 225 Electrical Degrees
Z width min = 180 Electrical Degrees
Z width Max = 540 Electrical Degrees

Z Gated to A
Z width min = 135 Electrical Degrees
Z with max = A true

Z Gated to A&B
Z width min = 45 Electrical Degrees
Z width Max = A&B true

incremental-encoder-gated1

Ungated Z
Z true over A&B> 45 Electrical Degrees
Z-A&B/A&B-Z min = 0 Electrical Degrees
Z-A&B/A&B-Z max= 315 Electrical Degrees
Z width min = 180 Electrical Degrees
Z width Max = 540 Electrical Degrees

Z Gated to A
Z width min = 135 Electrical Degrees
Z with max = A true

Z Gated to A&B
Z width min = 45 Electrical Degrees
Z width Max = A&B true

More information on ‘Quick Ship’ Industrial Rotary and Modular Shaft Encoders can be viewed at-

http://servo2go.com/supplier.php?id=1057843244

For more information please contact:

sales@servo2go.com
Toll Free Phone:   877-378-0240
Toll Free Fax:       877-378-0249
www.servo2go.com

 

Tags:  Encoder, Incremental Encoder, Absolute Encoder, Single-Ended Encoder, Differential Encoder, Servo2Go, Quantum Devices

 

 

The no assembly hassle industrial optical encoder from Quantum Devices May 7, 2014

Posted by Servo2Go.com in New Product Press Releases.
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The QPhase™ QD200 has been designed to eliminate the assembly hassle and hidden cost of installing modular or kit encoders onto OEM products.  The QD200 is a complete operational unit with an integral dual ABEC 5, ball bearing, insert molded hollow shaft support that provides the mechanical stability for this low profile (0.93” high by 2.00” diameter) high resolution encoder package.  Using our proprietary sensing technology we are able to obtain an incremental, 5000 PPR, plus Index pulse, without the use of interpolation schemes.  The stainless steel flexible spring mount provides for 30° rotational adjustment to permit precise commutation alignment and has been designed to allow for more motor tail shaft run out than typical modular or kit type units can tolerate.

Quantum Devices QD200 Optical Encoder

Quantum Devices QD200 Optical Encoder

Product options include: 120° C continuous ambient operating temperature, 4 to 8 pole three phase commutation signals for brushless motors, 5–26 VDC operating input voltages, high voltage line driver outputs on both incremental and commutation lines and standard resolutions from 500 PPR to 5000 PPR derived directly from the encoder disc.

More information on the QD200 optical encoder from Quantum Devices can be found at the link below-

https://www.servo2go.com/product.php?ID=100130&cat=

For more information, please contact:

Editorial Contact:

Warren Osak
sales@servo2go.com
Toll Free Phone:  877-378-0240
Toll Free Fax:   877-378-0249
www.servo2go.com

 

Tags:  Encoder, Incremental Encoder, Absolute Encoder, Single-Ended Encoder, Differential Encoder, Servo2Go, Quantum Devices

 

Understanding Incremental Encoder Signals April 29, 2014

Posted by Servo2Go.com in Technical Support Information.
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Which incremental encoder wires should I use?

Channels A & B (Incremental Channels)

Use only A (or only B) for an RPM or counting applications where the rotation is either unidirectional, or where you don’t need to know direction.

Use A and B together to know direction.  After two low pulses the next high pulse indicates direction.  This is due to the phasing offset between A and B of 90 electrical degrees, placing the signals in what is known as quadrature.

These signals can also be used to set up an up/down counter.

Index pulse, also known as Z, marker, or I

Index pulse is a pulse that occurs once per rotation.  It’s duration is nominally one A (or B) electrical cycle, but can be gated to reduce the pulse width.

The Index (Z) pulse can be used to verify correct pulse count.

The Incremental Encoder Index pulse is commonly used for precision homing.  As an example, a lead screw may bring a carriage back to a limit switch.  It is the nature of limit switches to close at relatively imprecise points.  This only gives a coarse homing point.  The machine can then rotate the lead screw until the Z pulse goes high.

For a 5000 line count encoder this would mean locating position to within 1/5000 of a rotation or a precision of .072 Mechanical Degrees.  This number would then be multiplied against lead screw travel.

Commutation (UVW) signals are used to commutate a brushless DC motor.  I always like to compare these signals to that of a distributor in a car.  The commutation (sometimes called “Hall”) signals tell the motor windings when to fire

You would need to have encoder commutation signals if the motor you are mounting the encoder to has a pole count and there is no other device doing the work of commutation.  It is important to note that commutation signals need to be aligned or “timed” to the motor.

Single ended vs differential

These terms refer not to the waveforms of signals, but instead to the way the signals are wired.

Single ended wiring uses one signal wire per channel and all signals are referenced to a common ground.

TTL and Open Collector are types of single ended wiring.

Differential wiring uses two wires per channel that are referenced to each other.  The signals on these wires are always 180 electrical degrees out of phase, or exact opposites.  This wiring is useful for higher noise immunity, at the cost of having more electrical connections.

Differential wiring is often employed in longer wire runs as any noise picked up on the wiring is common mode rejected.

RS-422 is an example of differential wiring.
More information on ‘Quick Ship’ Industrial Rotary and Modular Shaft Encoders can be viewed at-

http://servo2go.com/supplier.php?id=1057843244

For more information please contact:

sales@servo2go.com
Toll Free Phone:   877-378-0240
Toll Free Fax:       877-378-0249
www.servo2go.com

Tags:  Encoder, Incremental Encoder, Absolute Encoder, Single-Ended Encoder, Differential Encoder, Servo2Go, Quantum Devices