background image

Rev 22 Feb 2019

Page 23

Chapter 5 Troubleshooting

Overshoot in position signal which grows over time

It is possible that the position of the motor may show an overshoot when driven with
a large square wave or similar, and that this overshoot will grow with time until a fault
is  triggered.  There  is  usually  a  certain  frequency  and  amplitude  above  which  this
starts to occur. This behaviour is caused by choosing a power supply which cannot
deliver enough current for the intended application. The oscillation builds up because
the power supply voltage is dropping on the rising edge of the position signal and
effecting the board's behaviour. With every rising edge the effect becomes slightly
greater as the overshoot grows.

Содержание GVS001

Страница 1: ...HA0193T GVS001 and GVS002 GVS101 and GVS102 GVS201 and GVS202 GVS301 and GVS302 Scanning Galvo Systems User Guide Original Instructions ...

Страница 2: ...tallation 10 3 3 Electrical Installation 12 Chaper 4 Operation 19 4 1 General Operation 19 4 2 External Enabling of the driver board 19 4 3 Using a DAQ Card 19 4 4 Recommended Scanning Angles 20 Chaper 5 Troubleshooting 21 5 1 Common Problems 21 5 2 Galvanometer Faults 24 Appendices Appendix A Specifications and Associated Products 25 1 1 Specifications 25 1 2 Associated Products 26 Appendix B Cal...

Страница 3: ...ks The driver cards feature a small footprint fixings for easy mounting to a heatsink and a simple analog command signal interface A choice of mirror coating is available as follows GVS001 and GVS002 Single and Dual Axis Systems with Protected Silver Mirrors GVS101 and GVS102 Single and Dual Axis Systems with Protected Gold Mirrors GVS201 and GVS202 Single and Dual Axis Systems with 400 750 nm Bro...

Страница 4: ... mirror mirror mount and driver electronics A description of each component in the system is contained in the following sections 1 2 2 The Galvanometer The galvanometer consists of two main components a motor that moves the mirror and a detector that feeds back mirror position information to the system Fig 1 2 GVS002 Dual Axis Galvo Mirror Assembly Our galvo motor features a moving magnet which me...

Страница 5: ...rmance of the system High resonant frequencies and enhanced stiffness in the mirror assembly also add to system performance by increasing bandwidth and response times Wavelength ranges and damage threshold of the different mirror coatings are details below Fig 1 3 Mirror Assembly Detail Part No Coating Wavelength Damage Threshold GVS00x Silver 500 nm 2 0 µm 3 J cm2 at 1064 nm 10 ns pulse GVS10x Go...

Страница 6: ... require vector positioning e g laser marking or raster positioning printing or scanning laser microscopy It can also be used in some step and hold applications Furthermore the proportional derivative circuit gives excellent dynamic performance and includes an additional current term to ensure stability at high accelerations The diagram below shows the architecture of the driver in more detail Fig...

Страница 7: ...n instruction or additional information Warning If this equipment is used in a manner not specified by the manufacturer the protection provided by the equipment may be impaired In particular excessive moisture may impair operation Spillage of fluid such as sample solutions should be avoided If spillage does occur clean up immediately using absorbant tissue Do not allow spilled fluid to enter the i...

Страница 8: ...nsions 3 1 1 Motor Assembly Dimensions Fig 3 1 Motor Dimensions 3 1 2 Mirror Dimensions Fig 3 2 Mirror Dimensions 0 09 2 3 0 06 1 5 1 22 31 0 Ø 0 9 23 2 1 49 37 8 0 87 22 0 Ø 0 5 12 6 Ø 0 1 2 5 all dimensions in inches mm 0 57 14 5 0 34 8 5 0 04 1 0 0 04 1 0 0 39 10 0 0 32 8 0 X Axis Mirror Y Axis Mirror all dimensions in inches mm ...

Страница 9: ...imensions in inches mm 1 5 38 0 0 75 19 0 0 53 13 5 0 53 13 5 0 35 9 0 0 35 9 0 0 33 8 5 0 33 8 5 2 x Ø2 5 8 0 M3 x 0 5 6H 6 0 2 x Ø 2 5 8 0 M3 x 0 5 6H 6 0 M3 x 0 5 6H 0 12 3 0 Ø 0 52 13 2 0 43 11 0 0 43 11 0 R 0 04 1 0 0 79 20 0 0 65 16 5 1 38 35 0 0 03 0 75 0 06 1 5 Qty 5 SLOTS 0 08 2 0 Typ 0 08 2 0 Typ 0 59 15 0 0 98 25 0 0 39 10 0 0 17 4 3 Ø 6 0 3 0 Ø 3 5 to SLOT ...

Страница 10: ... 38 0 0 6 16 0 0 75 19 0 1 1 28 0 0 98 25 0 0 39 10 0 0 75 19 0 0 24 6 0 0 87 22 0 0 55 14 0 1 34 34 0 0 55 14 0 0 2 5 0 0 06 1 5 0 06 1 5 0 39 10 00 0 04 1 0 0 07 1 8 0 2 5 0 0 2 5 0 0 2 5 0 M3 x 6 Qty 3 M3 x 6 Qty 3 Ø 0 52 13 2 Ø 0 52 13 2 Ø 0 14 3 5 CSK 0 24 6 0 Qty 2 0 39 10 00 1 16 29 5 1 58 40 0 0 02 0 5 0 02 0 5 0 17 4 3 0 34 8 5 all dimensions in inches mm ...

Страница 11: ... Thru 52 0 2 05 19 0 0 75 GHS002 97 0 3 82 11 20 0 44 10 40 0 41 3 0 0 12 24 0 0 94 25 0 0 98 85 1 44 2 1 74 7 2 0 28 1 6 0 06 24 2 0 95 M3 3 Positions 3 5 0 14 DIA 25 5 1 0 45 88 1 81 66 0 2 6 74 0 2 9 5 0 0 2 9 07 0 36 45 0 1 77 33 0 1 3 15 0 0 59 3 0 0 12 4 8 0 19 3 0 0 12 6 0 Typ 2 36 54 0 2 13 Slot 52 5 2 07 74 8 2 95 3 3 0 13 6 5 0 26 All dimensions in mm inches 3 5 0 14 DIA and CSK to Suit ...

Страница 12: ...n the average speed at which the user moves the scanners The larger the power the heatsink must dissipate the larger the heatsink will need to be 3 2 2 Fitting The Heatsinks Caution The galvo motor assembly and associated driver board are tuned at the factory before they are shipped and further adjustment is not normally necessary If the accuracy of the system is in doubt e g due to accidental adj...

Страница 13: ... bracket will provide adequate heat sinking however for more vigorous applications it may be necessary to fit some heatsinking in addition to the galvo motor mount Thorlabs supply a combined post adapter and heatsink GHS003 suitable for both single and dual axis applications If using a third party heatsink please see Appendix B for details on how to calculate the power dissipation in the motor 1 S...

Страница 14: ...pply to power the galvo controller board s as this power supply has been specifically designed for this purpose The GPS011 can power up to two driver cards under any drive conditions and is supplied with all the cables required to connect to the driver cards However customers also have the option of using a third party power supply or incorporate the boards into their existing system In this case ...

Страница 15: ... power supplies can be used with the Thorlabs galvo systems however it is important to limit the inrush current when the power supply is turned on in order to ensure that the power supply reservoir capacitors on the board are not damaged by the large surge currents that can occur on power up Most power supplies naturally soft start when they are switched on at the mains side and provide inrush cur...

Страница 16: ...itable PSU GPS011 for powering a single or dual axis system see Section 3 3 1 A bare cable crimp connectors Molex Pt No 2478 and housings for use with general lab PSUs is supplied with each driver board Fig 3 13 J10 Power Connector Pin Identification Caution During the electrical installation cables should be routed such that power and signal cables are separated so that electrical noise pick up i...

Страница 17: ...d motors are calibrated with these cables Using different cables will affect the performance of the system Longer cables are available as a custom part but the units will require re calibration if these are not specified at time of order Contact tech support for more details 1 2 3 4 5 6 7 8 Pin 1 Position Sensor A Current Pin 2 Position Sensor Ground Pin 3 Position Sensor Cable Shield Pin 4 Drive ...

Страница 18: ...tempt to set the mirror position to the command input value Pin 3 DRV_OK is an open collector output that is low when the board is operating normally and floating if a fault occurs To use Pin 3 as a fault indicator connect a pull up resistor to give a high signal when the fault occurs DRV_OK limits are 30 mA 30 V Do not connect a relay to this output Note All diagnostic signals from J6 have 1 KW o...

Страница 19: ...nnector Details Mating Connector body Manufacturer Molex Mfr P N 513530800 Example Vendor Farnell Vendor P N 1120387 Crimps 22 26AWG Manufacturer Molex Mfr P N 56134 8100 Example Vendor Farnell Vendor P N 1120545 Crimps 22 28AWG Manufacturer Molex Mfr P N 56134 9100 Example Vendor Farnell Vendor P N 1120546 ...

Страница 20: ...es the current which then determines the acceleration It is not required if the user only wants to monitor position 3 3 5 Setting the Volts Degree Scaling Factor Servo driver cards manufactured after October 2015 have a jumper which is used to set the Volts per Degree scaling factor The cards are shipped with the scaling set to 0 8 V where the max scan angle is 12 5 and is compatible with driver c...

Страница 21: ...enabled If a logic low signal is applied then the driver will be disabled 4 3 Using a DAQ Card Typically users will deploy a DAQ card with DAC analogue outputs in order to drive the servo drivers supplied with the galvos The minimum recommended specifications for the DAC outputs are Dual bipolar 10V to 10V DAC analogue output channels differential DAC clocking frequency higher than 20kS s Kilo Sam...

Страница 22: ...vement from the center as shown below Lastly on dual axis systems there is an offset alignment between the X and Y axis mirrors that also limits the scan angle The table below gives recommended scanning angles for various beam diameters GVS001 GVS101 GVS201 and GVS301 Input Beam Diameter Mechanical Scan Angle Optical Scan Angle 4 mm and less 12 5 25 5 mm 10 12 5 20 25 GVS002 GVS102 GVS202 and GVS3...

Страница 23: ...rs However under normal circumstances the instability should be detected by the fault control circuitry In this case the behaviour most likely to be observed by the user is the following The mirror will suddenly jump from one position to another probably with a short burst of whistling and stop and remain still After a delay of a few seconds the mirror will jump to another position and so on Here ...

Страница 24: ...r current If the galvo system is drawing more current than expected if the scanners or the driver cards are overheating if the scanners are making a hissing noise or if the position accuracy is less than expected this may be due to oscillations in the galvo motor current This can be identified by viewing the coil current signal J6 pin 4 on an oscilloscope The problem will manifest itself as a high...

Страница 25: ...e until a fault is triggered There is usually a certain frequency and amplitude above which this starts to occur This behaviour is caused by choosing a power supply which cannot deliver enough current for the intended application The oscillation builds up because the power supply voltage is dropping on the rising edge of the position signal and effecting the board s behaviour With every rising edg...

Страница 26: ...ew seconds The table below shows the various faults states which can be triggered in the fault control circuitry Table 5 1 Galvo System Faults and Associated Fault Protection Circuit Action Fault Possible Causes Action Taken by Fault Control Circuit Maximum scanner position exceeded Drive signal too large instability of scanner Power amplifier turned off Maximum peak current Exceeded Incorrect tun...

Страница 27: ...10x 2 J cm2 at 1064 nm 10 ns pulse GVS20x 0 25 J cm2 at 532 nm 10 ns pulse GVS30x 5 J cm2 at 1064 nm 10 ns pulse Motor Position Sensor Linearity 99 9 range 20 Scale Drift 40PPM C Max Zero Drift 10 µRad C Max Repeatability 15 µRad Resolution With GPS011 Linear PSU With standard switch mode PSU 0 0008 15 µRad 0 004 70 µRad Average Current 1 A Peak Current 5 A Load Mirror Aperture 5 mm Coil Resistanc...

Страница 28: ...Scale Factor switchable 0 5V 0 8V or 1 0V Mechanical Position Signal Output Scale Factor 0 5V Operating Temperature Range 0 40 C Servo Board Size L x W x H 85 mm 74 mm 44 mm 3 35 x 2 9 x 1 73 Product Name Part Number 2D Galvo System Protected Silver Mirrors GVS002 1D Galvo System Protected Silver Mirror GVS001 2D Galvo System Protected Gold Mirrors GVS102 1D Galvo System Protected Gold Mirror GVS1...

Страница 29: ...oltage and V is the negative supply voltage 2 1 1 Calculating the Required Thermal Conductivity The ability of a heatsink to transfer heat to its surroundings is parameterised either by its thermal conductivity k or its thermal resistance Ø The lower the thermal resistance the more effectively the heatsink can transfer heat The required thermal resistance can be calculated from the following equat...

Страница 30: ...fact that the distance between mirror 1 and the image field depends on the size of the mechanical scan angles of mirror 1 and mirror 2 A larger scan angle leads to a longer distance 2 The distance in the image field is not proportional to the scan angle itself but to the tangent of the scan angle Therefore the marking speed of the laser focus in the image field is not proportional to the angular v...

Страница 31: ...019 Page 29 Chapter 5 Troubleshooting As a result you will find the scanning field turn out to be a pillow shaped image see Fig C 2 below Fig C 2 Pillow shaped Field Distortion Caused by the Arrangement of Mirrors ...

Страница 32: ...ble protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communications Operation of this equipment in a residential area is likely to cause harmful interference in which ca...

Страница 33: ...Rev 22 Feb 2019 Page 31 Chapter 5 Troubleshooting D 2 CE Certificates ...

Страница 34: ...Page 32 18728 D01 Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters ...

Страница 35: ...Rev 22 Feb 2019 Page 33 Chapter 5 Troubleshooting ...

Страница 36: ...Page 34 18728 D01 Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters ...

Страница 37: ...Rev 22 Feb 2019 Page 35 Chapter 5 Troubleshooting ...

Страница 38: ...Page 36 18728 D01 Single and Dual Axis Scanning Galvo Systems for Small Beam Diameters ...

Страница 39: ...Rev 22 Feb 2019 Page 37 Chapter 5 Troubleshooting ...

Страница 40: ...us West Coast Email sales thorlabs com Support techsupport thorlabs com Europe Thorlabs GmbH Hans Böckler Str 6 85221 Dachau Germany Tel 49 0 8131 5956 0 Fax 49 0 8131 5956 99 www thorlabs de Email europe thorlabs com France Thorlabs SAS 109 rue des Côtes 78600 Maisons Laffitte France Tel 33 0 970 444 844 Fax 33 0 825 744 800 www thorlabs com Email sales fr thorlabs com Japan Thorlabs Japan Inc 3 ...

Страница 41: ...www thorlabs com ...

Отзывы: