Cambridge Technology 6220H Instruction Manual

______________________________________________________________________________

Model 6220H

Galvanometer Optical Scanner

INSTRUCTION MANUAL

CAMBRIDGE TECHNOLOGY, INC.

25 Hartwell Avenue

Lexington, MA 02421

U.S.A.

TEL.[phone] FAX. [phone]

www.cambridgetechnology.com

Revision 3.1, August 8, 2010

Cambridge Technology Model 6220H Instruction Manual

TABLE OF CONTENTS

1.0 Introduction and Warnings _______________________________________________ 3

2.0 Specification ____________________________________________________________ 5

3.0 Description of Operation__________________________________________________ 7

3.1 Overview _____________________________________________________________ 7

3.2 Mounting Scheme ______________________________________________________ 8

3.3 Mirror Mount and Mirrors _____________________________________________ 10

3.4 Cabling ______________________________________________________________ 11

3.4.1 Attaching the Cable to the Motor ____________________________________ 12

3.4.2 Modifying the Cable Length ________________________________________ 13

3.5 The 6220HM _________________________________________________________ 15

3.5.1 Field Replacement of the Bumpers ___________________________________ 15

4.0 Limited Warranty ______________________________________________________ 16

5.0 Appendix______________________________________________________________ 17

5.1 Schematics and Mechanical Drawings ____________________________________ 17

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Cambridge Technology Model 6220H Instruction Manual

1.0 Introduction and Warnings

This manual was written to help the customer use the Model 6220H scanner successfully. There
are several warnings and precautions written throughout this manual. Read this manual
carefully. It is possible to damage the scanner by exposing it to rough handling or contaminants.

As the demand for speed and accuracy of today's optical systems increases, so does the need for
high performance, high accuracy scanners. This scanner was designed for just those applications
that require ultra-high speed and accuracy.

Note: Throughout this manual the terms mechanical angle and optical angle will be used. For
all applications the mechanical angle refers to the angular change of the scanner shaft. For most
optical systems the optical angle is the angular change of the beam. For these optical systems,
the:

optical angle = 2 x mechanical angle

WARNING! Upon system shutdown or malfunction, the scanner has the ability to point the
beam anywhere within ~200° optical. It is up to the end user to limit the exit window of the laser
beam in order to provide laser safety.

CAUTION! Ensure that the scanner and/or the XY mount have adequate heatsinking to
allow scanner operation. Never operate the scanner without a heatsink! The scanner will
suffer irreparable damage if allowed to overheat! For more information, refer to Section

3.2. The Cambridge Technology XY mount is a sufficient heatsink only if bolted to a
customer supplied adequate heatsink to conduct away the heat. It is recommended the
customer use thermal grease between the scanner body and the XY mount to maximize
heat dissipation.

Note: These scanners are high performance devices that require some special handling. Never let

them impact a hard surface especially on the front shaft. Do not pull or push with anything other
than light finger pressure on the front shaft or damage to the front bearing can occur. Do not
expose the scanner to extremes of temperature outside the operating limits shown in the
specifications Section 2.0. Do not let any foreign material, e.g. dust, dirt, solvent, water, oil, etc.
come in contact with the front bearing. It is located right at the front end of the scanner. Foreign
material inside the bearing will reduce bearing life.

Note: As with any high performance motor, resonances created during power up, power down,
normal operation, or during tuning can cause serious motor degradation or failure. Always keep
the motor under proper servo control and do not let the motor swing uncontrolled into the
bumper stops.

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Cambridge Technology Model 6220H Instruction Manual

Note: Lead free solder (SAC 305) should be used to solder or unsolder any connections on the
position detector board. This scanner is now fully RoHS compliant. Using leaded solder can
result in failed solder joints due to incompatibility of the two types of solder and will make the
entire assembly non-RoHS compliant.

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Cambridge Technology Model 6220H Instruction Manual

2.0 Specification

Note: All angles are in mechanical degree unless stated otherwise.

Scanner MODEL NO. 6220H Tolerance Units/Notes

Mechanical Specifications

Rated Excursion, Rotor1 ±20 Min degrees
Bumper Stop Angle, Initial Contact1 ±26 ±4 degrees
Optical Aperture, Two-Axis, Std. 5, 8 - millimeters
Rotor Inertia 0.125 ±10% gm-cm2
Recommended Load 0.000 – 1.25 - gm-cm2
Torque Constant 6.17E+04 ±10% dyne-cm/amp
Coil Resistance 2.79 ±10% ohms
Coil Inductance 180 ±10% µhenries
Back EMF Voltage 108 ±10% µv/degrees/s
Thermal Resistance, Rotor-to-Case 1.0 Max °C/watt
Maximum Rotor Temperature 110 Max °C
Maximum RMS Current 3.9 Max amps
Maximum Peak Current 20 Max amps
Maximum RMS Power 60 Max watts
Fuse Rating 5 - amp., fast-blo
Settling time2 200 Typ µsec
Scanner Weight 42 Typ grams
Case Operating Temperature 0 – 50 Typ °C

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Cambridge Technology Model 6220H Instruction Manual

Position Detector, PD

Linearity 99.9 Min % over ±10°

99.5 Typ % over ±20°
Scale Drift 50 Max PPM/°C
Zero Drift 15 Max uradians/°C
Repeatability, Short Term 8 Max µrad.
Output Signal, Diff. Mode 11.7 ±20% µA/°diff.@I
Output Signal, Common Mode 155 ±20% µA@I
PD Power Requirements 30 ±20% mA, DC

1.4 Nom volts.

-----------------------------------------------------------------------------------------------------------------­Mounting Requirements: A single axis scanner mount must dissipate 6.0 watt/°C. for a

Notes: 1. 6220HM60 is reduced to ±15° excursion and ±18° initial contact.

2. Setup for settling time: Using CTI’s recommended servo, CTI’s 5mm Y-mirror,
moving a 0.1° step, and settled to within 99% of the final position.

3. Using the Cambridge Technology, Inc. Position Demodulator circuit.

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=155 µa

COM

= 30 ma

LED

mount temperature of 40°C. An XY mount must dissipate 12.0
watts/°C for a mount temperature of 40°C. See Section 3.2 for
more information.

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