Pa1 Power Amplifier Operation Manual

Transcript

Innovation in Magnetic Field Measuring Instruments Operation Manual for PA1 Power Amplifier www.bartington.com BARTINGTON INSTRUMENTS Table of Contents 1. About this Manual 3 1.1. Symbols Glossary 3 2. Safe Use 3 3. Introduction 4 3.1 PA1 Power Amplifier Features 5 3.1.1. PA1 Power Amplifier Front View 5 3.1.2. PA1 Power Amplifier Rear View 6 4. PA1 Power Amplifier Installation 7 4.1. Test Assembly Location and Ventilation Requirements 7 4.2. Connecting to the HCS1 System 7 4.3. Connecting to the HC1 or HC2 Helmholtz Coils 7 4.4. Connecting to the CU1 Control Unit 8 4.4.1. Pin-Outs 8 4.5. PA1 Power Amplifier Power 9 4.6. Amplifier O/P Circuit Breakers 9 4.7. Cooling 10 4.8. Static Field Compensation 10 4.8.1. Method 11 5. Coil Calibration and Alignment Adjustment 5.1. Calibration Process 11 12 5.1.1. X Trim, Y Trim & Z Trim 12 5.1.2. X Mon, Y Mon & Z Mon 12 5.1.3. Alignment trim 13 6. Air Intake Filter Cleaning and Replacement 14 7. Absolute Maximum Voltages and Ratings 15 8. Troubleshooting, Care and Maintenance 15 9. Storage and Transport 15 10. Disposal 15 10.1. Waste Electrical and Electronic Equipment (WEEE) Regulations 16 Appendix A: Connecting the Components of the HCS1 Helmholtz Coil System 17 Appendix B: Guidance for Connection to Mains Supply 18 Page 2 of 19 OM3225/2 BARTINGTON INSTRUMENTS 1. About this Manual This manual provides the information necessary to help customers install and operate the PA1 Power Amplifier. The PA1 Power Amplifier is one component of Bartington Instruments’ One, Two or Three-Axis Helmholtz Coil Control System. This manual should therefore be read in conjunction with: • OM3226 HC1 Helmholtz Coil or OM3342 HC2 Helmholtz Coil • OM3224 CU1 Control Unit. Both are available via the Helmholtz Coil System product page at www.bartington.com. This manual should also be read in conjunction with the product brochure (DS2613) which can also be found on the product page. Photographs of key components are included, labelled with numbers. A number in the text in square brackets [ ] refers to that label. Bartington Instruments cannot advise on the integration of this equipment with any third party products. 1.1. Symbols Glossary The following symbols used within this manual call your attention to specific types of information: WARNING: Indicates a situation in which serious bodily injury or death could result if the warning is ignored. Caution: Indicates a situation in which bodily injury or damage to your instrument, or both, could result if the caution is ignored. Identifies items that must be disposed of safely to prevent unnecessary damage to the environment. Note: A paragraph in this format provides useful supporting information on how to make better use of your purchase. 2. Safe Use WARNING: The PA1 Power Amplifier is powered by mains electricity and contains uninsulated parts. Ensure that the unit is properly earthed at all times. Do not open the casing or have contact with any internal parts except where following a procedure precisely Page 3 of 19 OM3225/2 BARTINGTON INSTRUMENTS as described in this manual. Safety protection will be impaired if the unit is used in a manner not specified in this manual. WARNING: The electromagnetic field from this product may interfere with the operation of pacemakers and other medical devices. Consult your device’s manufacturer before operation. WARNING: These products are not qualified for use in explosive atmospheres or life support systems. Consult Bartington Instruments for advice. WARNING: Personal injury may result from lifting the PA1 Power Amplifier. Use more than one person to move this device. It should be carried by each of the four lower corners. CAUTION: When operated at full power for extended periods of time, thermal cut-out may be activated to protect the equipment from overheating. Should this occurs, the power will to the PA1 will be cut. In such event, it is advised to allow the unit to cool down before restarting it. To prevent the thermal cut-out from activating, the equipment should be used in a cooled temperature controlled environment (refer to Section 4.6) 3. Introduction The PA1 Power Amplifier is the power amplifier for the HCS1 Helmholtz Coil Control System. The full HCS system consists of: • HC1 or HC2 Helmholtz Coils: an assembly of up to three Helmholtz coils. See OM3226 (HC1) or OM3342 (HC2). • PA1 Power Amplifier. • CU1 Control Unit: the control unit for the system which enables it to interface with a PCbased test, measurement and control system. See OM3224. A diagram showing the connection of these separate items into one system is given in Appendix A. The PA1 Power Amplifier is available in a number of variants to match the coil assembly it is being used with: • PA1-1X, PA-1Y, and PA1-1Z Single Axis versions • PA1-2XY, PA1-2YZ, and PA1-2XZ Two Axes versions • PA1-3 Three Axes version Page 4 of 19 OM3225/2 BARTINGTON INSTRUMENTS 3.1 PA1 Power Amplifier Features 1 2 4 3 5 6 6 10 9 8 7 3.1.1. PA1 Power Amplifier Front View Key 1. Upper front panel 2. Current control input (takes input from signal generator) 3. Calibration controls, behind transparent plastic cover 4. Current monitor output 5. Static field offset controls 6. Fastening screws 7. Rocker switch 8. Lower front panel 9. Centre front panel (grille) 10. Amplifier O/P circuit breakers Page 5 of 19 OM3225/2 BARTINGTON INSTRUMENTS 3.1.2. PA1 Power Amplifier Rear View 11 12 12 16 14 15 13 Key 11. Blank ventilation panel 12. Fastening screws 13. Coil drive output to the HC1 or HC2 Helmholtz Coils 14. Lower rear panel 15. Circuit breaker 16. Mains power input socket Page 6 of 19 OM3225/2 BARTINGTON INSTRUMENTS 4. PA1 Power Amplifier Installation 4.1. Test Assembly Location and Ventilation Requirements The PA1 amplifier must be positioned such that the front, sides and rear ventilation panels are not obstructed to allow free movement of cooling air. The CU1 has no forced ventilation requirements and can be sited close to the PA1. Note: The HCS1 coil system should be positioned around 3m away from the amplifier to reduce noise pick up from the amplifier. Note: For optimum results the ambient temperature should not exceed the maximum specified in the data sheet DS2613. 4.2. Connecting to the HCS1 System The PA1 Power Amplifier connects to the HC1 or HC2 Helmholtz Coils and the CU1 Control Unit. The HC1 or HC2 Helmholtz Coil connection to the PA1 Power Amplifier is to power the coils only. See Section 4.2. See Section 4.3 for connecting to the CU1 Control Unit. 4.3. Connecting to the HC1 or HC2 Helmholtz Coils The HC1 or HC2 Helmholtz Coils are fitted with a cable with a plug for connection to the PA1 Power Amplifier. 13 The PA1 Power Amplifier and the HC1 or HC2 must be connected before the amplifier power is turned on. The supplied cable is plugged into the coil drive output socket on the rear of the PA1 Power Amplifier [13]. Page 7 of 19 OM3225/2 BARTINGTON INSTRUMENTS Caution: The coil drive output socket is reserved for the cable connecting the HC1 or HC2 and the PA1 Power Amplifier. No other connection should be made to this socket. 2 4 Note: The amplifier and any other control or measuring equipment must be at least 3m away from the coil assembly. Note: The PA1 Power Amplifier varies for Helmholtz Coils with different numbers of axes. One, two, and three axis PA1 versions are available. If an HC1 has a greater number of axes than the PA1 then only the number of axes corresponding to the PA1 can be used. 4.4. Connecting to the CU1 Control Unit The PA1 Power Amplifier is connected to the CU1 Control Unit via the current control input [2]. The current monitor output [4], located on the upper front panel of the PA1 Power Amplifier, is also connected to the CU1. Note: A diagram showing the interconnection of components of the HCS1 System is given in Appendix A. In order to achieve a good noise rejection, the input and current monitor output are differential/ balanced signals. Single ended/unbalanced sources may be used by connecting the input negative signals to the source ground. The output may be connected to a single-ended input by using the positive signal and leaving the negative output disconnected; however the output signal will be reduced to half the specified value. WARNING: Do not connect either positive or negative outputs to ground. 4.4.1. Pin-Outs Pin-out information for the current control input and the current monitor output can be found on the PA1 Outline Drawing DR3047 available from the product page on our website. http://www.bartington.com/helmholtz-coil-three-axis-system. Page 8 of 19 OM3225/2 BARTINGTON INSTRUMENTS 4.5. PA1 Power Amplifier Power Details of suitable power supply for the PA1 Power Amplifier are provided in the product brochure, with the supply beeing earthed/grounded. The supply from a standard wall outlet should be suitable in most countries. A compatible mains cable supplied with a UK 13A connector, an EU connector or bare ends can be specified at the time of ordering. 15 A 16A circuit breaker is situated on the rear panel [15] which is suitable for the supply stated in the product brochure. Contact Bartington Instruments for advice if a lower voltage is to be used. 4.6. Amplifier O/P Circuit Breakers Each amplifier o/p is fitted with a resettable 20A circuit breaker [10], which protects both the amplifiers and the coil assembly in the event of a fault. The breakers are normally in the reset position. If a breaker trips, it can be reset by pressing in the appropriate button on the front panel. Repeated tripping may be an indication of a system fault. Page 9 of 19 OM3225/2 BARTINGTON INSTRUMENTS 4.7. Cooling The amplifier is fan-cooled so needs an unimpeded airflow from front to rear. A self-resetting thermal shut-down mechanism will prevent damage through overheating. 9 Caution: If used on full power ensure that the equipment is placed in a cool, controlled environment to prevent activation of the thermal cut-out. Caution: The air filter in the front panel [9] should be inspected regularly, and cleaned or replaced when necessary. See Section 6. 4.8. Static Field Compensation 17 5 18 The static field is offset by introducing a DC offset into the amplifier input. Lockable controls for static field offset [5] are available on the amplifier upper front panel to set this compensation. The static field compensation should be set individually for each axis to obtain a minimum field in the centre of the coil. This should be measured by a magnetometer placed in the coil centre. Bartington Instruments can provide a suitable magnetometer. Page 10 of 19 OM3225/2 BARTINGTON INSTRUMENTS 4.8.1. Method The controls are locked by the outer hexagonal lock [17] which should be loosened with a spanner. The compensation is adjusted by turning the central shaft [18] with a screwdriver. A static field of below 100nT should be easily attained. The control should then be locked by tightening down the outer hexagonal lock whilst holding the centre shaft with the screwdriver. Once complete, recheck the offset of each axis. Note: The compensation current will appear as part of the field current measured by the field monitor. This adjustment should be checked regularly and will certainly need setting on installation, or should the coil or metalwork in the vicinity of the coil be moved, or should other sources of magnetic fields be introduced into the surroundings. 5. Coil Calibration and Alignment Adjustment The calibration controls are mounted on the upper front panel of the PA1 Power Amplifier behind a transparent cover [19]. To gain access to the controls, the cover must be carefully removed by unscrewing the two screws. Adjustments are made with a small screwdriver. 19 20 21 22 29 23 25 30 24 31 26 27 28 Note: On PA1 Power Amplifiers intended for use with one or two axis Helmholtz coils, either one or two axis controls will be missing from the front panel. In this case ignore references to missing axes when reading this manual. Page 11 of 19 OM3225/2 BARTINGTON INSTRUMENTS The identities and functions of the calibration controls are as follows. Image label Control label Function [20] X Trim X axis gain adjust [21] X->Y X axis alignment trim in Y axis [22] X->Z X axis alignment trim in Z axis [23] Y Trim Y axis gain adjust [24] Y->X Y axis alignment trim in X axis [25] Y->Z Y axis alignment trim in Z axis [26] Z Trim Z axis gain adjust [27] Z->X Z axis alignment trim in X axis [28] Z->Y Z axis alignment trim in Y axis [29] X Mon X axis current monitor gain adjust [30] Y Mon Y axis current monitor gain adjust [31] Z Mon Z axis current monitor gain adjust 5.1. Calibration Process Calibration should be carried out using an AC signal, away from 50 or 60Hz and their harmonics, and away from DC and slowly varying interferences. We use for example a 35Hz signal. The use of a true RMS reading voltmeters will enable the user to measure only the AC component of a signal. For HC1, a 1Vrms input signal on the PA1 will correspond to a 100μTrms field. The output of the magnetometer may also be monitored on an oscilloscope to ensure that there is no distortion of the waveform. Note: In the event of a single or two axis Helmholtz Coil being used, discard calibration instructions related to an axis that is not present on the system being used. Note: Further information can be found in the detailed calibration document available on request. Please contact Bartington Instruments. 5.1.1. X Trim, Y Trim & Z Trim Feed a signal from the signal generator into each axis in turn. Adjust the axis gains until the magnitude of the measured field matches the magnitude expected from the input signal level. 5.1.2. X Mon, Y Mon & Z Mon Feed a signal from the signal generator into each axis in turn. Adjust the monitor gains until the magnitude of the output matches the magnitude of the measured field. Page 12 of 19 OM3225/2 BARTINGTON INSTRUMENTS 5.1.3. Alignment trim In order to compensate for any small alignment inaccuracy in the test magnetometer, two measurements are made, in each axis, with the magnetometer being rotated about the measurement axis by 180 degrees and the average of the two voltages taken. When working with an AC field, the axis alignment trim control is adjusted until the reading is the same each time the test magnetometer is rotated about the axis being aligned. X axis alignment trim in Y axis Feed a signal from the signal generator into the X axis. Monitor the Y axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the Y axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. X axis alignment trim in Z axis Feed a signal from the signal generator into the X axis. Monitor the Z axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the Z axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. Y axis alignment trim in X axis Feed a signal from the signal generator into the Y axis. Monitor the X axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the X axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. Y axis alignment trim in Z axis Feed a signal from the signal generator into the Y axis. Monitor the Z axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the Z axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. Z axis alignment trim in X axis Feed a signal from the signal generator into the Z axis. Monitor the X axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the X axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. Page 13 of 19 OM3225/2 BARTINGTON INSTRUMENTS Z axis alignment trim in Y axis Feed a signal from the signal generator into the Z axis. Monitor the Y axis output of the calibration magnetometer. Initially adjust the trim control until a minimum is obtained. Then rotate the test magnetometer through 180° about the Y axis. If a signal is found then adjust the trim control until the same level is observed when the magnetometer is in the normal position and rotated position. 6. Air Intake Filter Cleaning and Replacement 34 33 33 34 32 The air filter consists a 440x85mm (approx.) foam pad [32] fitted behind the centre front panel of the PA1 Power Amplifier. It should be cleaned or replaced when necessary. WARNING: Disconnect mains supply before removing filter panel. The earth bonding connector can then be disconnected if required. Fan filter maintenance must be performed by suitably trained personnel only. Remove the power connector from the lower rear panel before removing the centre front panel. The centre front panel can be removed by loosening the four large screws in the corners [33]. The filter may be cleaned by brushing off any dust from the front and blowing through from the inside surface. Caution: Air should be blown with a low pressure air line. Use appropriate personal protective equipment (PPE). Should the filter need replacing, the old filter can be removed by taking out the six screws [34] holding the filter retaining bracket. Replace the filters with appropriate flame retardant filter material (contact Bartington Instruments for details). Replace the filter retention bracket and screws. When filter maintenance is complete, replace the earth bonding wire connector (if disconnected), before replacing the centre front panel. Page 14 of 19 OM3225/2 BARTINGTON INSTRUMENTS WARNING: Ensure the earth bonding wire is firmly re-attached to the panel before refitting. 7. Absolute Maximum Voltages and Ratings See the product brochure for the maximum voltages that may be applied to the PA1 Power Amplifier control input, current monitor output and coil drive output Refer to the product brochure for this product’s maximum environmental, electrical and mechanical ratings. Caution: Exceeding the maximum environmental ratings may cause irreparable damage to the equipment. Caution: If these voltages are exceeded, this may cause damage to the equipment. Caution: Do not make any other connection to these ports. 8. Troubleshooting, Care and Maintenance In the event of any apparent malfunction, email: [email protected] or telephone the Bartington Instruments service team on: +44 (0)1993 706565. 9. Storage and Transport The PA1 Power Amplifier is a precision electronic instrument and should be treated as such. Bartington Instruments has supplied this product in appropriate packaging for transportation. This packaging should be used for any future transport. Due to the weight of the equipment it should be moved by at least two people and carried by each of the four lower corners. 10. Disposal This product should not be disposed of in domestic or municipal waste. For information about disposing of this product safely, check local regulations for disposal of electrical / electronic products. Page 15 of 19 OM3225/2 BARTINGTON INSTRUMENTS 10.1. Waste Electrical and Electronic Equipment (WEEE) Regulations This product complies fully with Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (RoHS) and WEEE Regulations current at the time of printing. Page 16 of 19 OM3225/2 BARTINGTON INSTRUMENTS Appendix A: Connecting the Components of the HCS1 Helmholtz Coil System PXI CHASSIS DAQ HC1 DAQ DUT Sensor Connector 0 Optional aux sensor if required Connector 1 CU1 Current Control Output Aux Input Device Test Input Current Monitor Input Current Monitor Output Current Control Input PA1 Current Output to HC1/HC2 Page 17 of 19 OM3225/2 BARTINGTON INSTRUMENTS Appendix B: Guidance for Connection to Mains Supply 1. Ensure that the mains feed is from a clean AC supply with the following characteristics:Voltage Range Frequency 100V to 240V AC 50/60Hz It is highly recommended that this mains feed is via an appropriate Residual Current Circuit Breaker, rated at 30mA trip current. This must comply with local regulations. 2. The mains input connectors are as follows:Device Power Amplifier PA1 Control Unit CU1 Input Connector IEC C20 IEC C14 Mating Cable Connector IEC C19 IEC C13 These cables are available in specific versions for most countries. 3. If an un-terminated IEC connector lead is supplied with the equipment, the wires must be wired accordingly:BROWN BLUE GREEN/YELLOW LIVE NEUTRAL EARTH 4. It is essential that the control unit CU1 and the Power Amplifier PA1 are properly earthed at all times. 5. It is recommended that the mains to each unit is supplied via an appropriate mains fuse:Power Amplifier PA1 Control Unit CU1 13A 13A This is appropriate for the use over the whole supply voltage range. 6. This installation MUST be carried out by a trained, competent person. 7. Before initial switch-on, an appropriate earth bonding test should be performed to ensure a robust earth connection. 8. To disconnect mains power, the mains supply cord must be removed from the rear panel mains input connector. Page 18 of 19 OM3225/2 OM3225/2 Bartington Instruments Limited T: +44 (0)1993 706565 5, 10 & 11 Thorney Leys Business Park F: +44 (0)1993 774813 Witney, Oxford, OX28 4GE, England E: [email protected] The specifications of the products described in this brochure are subject to change without prior notice. Bartington® is a registered trademark of Bartington Instruments Ltd. www.bartington.com