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Related Manuals for Stanford Research Systems SR510
Summary of Contents for Stanford Research Systems SR510
- Page 1 MODEL SR510 LOCK-IN AMPLIFIER 1290-D Reamwood Avenue Sunnyvale, CA 94089 U.S.A. Phone: (408) 744-9040 • Fax: (408) 744-9049 Email: info@thinkSRS.com • www.thinkSRS.com Copyright © 1985, 1987, 1989 Stanford Research Systems, Inc. All Rights Reserved Revision: 3.3 (11/2003)
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Page 3: Table Of Contents
Current Input Auto-Tracking Bandpass Filter Notch Filters Frequency Range Noise Measurements Output Filters Ratio Capability Computer Interface Internal Oscillator SR510 Block Diagram Block Diagram Signal Channel Reference Channel Phase-Sensitive Detector DC Amplifier and System Gain Microprocessor System Circuit Description Introduction... - Page 4 RS232 Interface GPIB Interface Power Supplies Internal Oscillator Calibration and Repair Introduction Multiplier Adjustments Amplifier and Filter Adjustments CMRR Adjustment Line Notch Filter Adjustment 2xLine Notch Filter Adjustment Repairing Damaged Front-End Appendix A: Noise Sources and Cures Johnson Noise '1/f' Noise Noise Spectrum Capacitive Coupling Inductive Coupling...
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Page 5: Safety And Preparation For Use
LINE VOLTAGE SELECTION The SR510 operates from a 100V, 120V, 220V, or 240V nominal ac power source having a line frequency of 50 or 60 Hz. Before connecting the... -
Page 7: Specifications
SR510 Specification Summary General Power 100, 120, 220, 240 VAC (50/60 Hz); 35 Watts Max Mechanical 17" x 17" x 3.5" (Rack Mount Included) 12 lbs. Warranty Two years parts and labor. Signal Channel Inputs Voltage: Current: Impedance Voltage: Current:... - Page 8 Acquisition Time 25 Sec at 1 Hz 6 Sec at 10 Hz 2 Sec at 10 kHz Slew Rate 1 decade per 10 S at 1 kHz Phase Control 90° shifts Fine shifts in 0.025° steps Phase Noise 0.01° rms at 1 kHz, 100 msec, 12 dB TC Phase Drift 0.1°/°C Phase Error...
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Page 9: Front Panel Summary
Front Panel Summary Signal Inputs Single Ended (A), True Differential (A-B), or Current (I) Signal Filters Bandpass: Line Notch: 2XLine Notch: Q-of-10 Notch Filter at twice line frequency (In or Out) Sensitivity Full scale sensitivity from 100 nV to 500 mV RMS for voltage inputs or from 100 fA to 500 nA RMS for current inputs. -
Page 10: Abridged Command List
Return the ‘REL’ Status Turn the ‘REL’ off Turn the ‘REL’ on Return Bandpass Filter Status Take out the Bandpass Filter Put in the Bandpass Filter Return the Reference LCD Status Display the Reference Frequency Display the Reference Phase Shift Return Dynamic Reserve Setting Set DR to LOW range Set DR to NORM range... -
Page 11: Status Byte Definition
The most significant bit is always zero. Example: Bit 1 'down' and all others 'up' for RS232 communication at 9600 baud, no parity, two stop bits, and no echo or prompts by the SR510. Bit 3 Baud Rate 19200 9600... -
Page 12: Front Panel
SR510 Guide to Operation Front Panel The front panel has been designed to be almost self-explanatory. The effect of each keypress is usually reflected in the change of a nearby LED indicator or by a change in the quantity shown on a digital display. -
Page 13: Dynamic Reserve
ACT indicates activity on the computer interfaces. This LED blinks every time a character is received by the SR510 or transmitted by the SR510. REM indicates that the unit is in the remote state and that the front panel controls are not operative. -
Page 14: Offset
currently displayed parameter. If the output is greater than 1.024 times full scale, the REL function will not be able to zero the output and the ON LED will blink. The offset value will then be set to its max value. If NOISE is being displayed when the REL function is turned on, the noise ouptut will require a sew seconds to settle again. -
Page 15: Reference Input And Trigger Levels
only by the ac 'wiggles' at the output. By measuring the noise at different frequencies, the frequency dependence of the noise density can be found. This usually has the form of v noise ~ 1/f. The noise computation assumes that the noise has a Gaussian distribution (such as Johnson noise). -
Page 16: Power Switch
whenever any of the PHASE keys are pressed. The phase ranges from -180 degrees to +180 degrees and is the phase delay from the reference input signal. Power This is the instrument's POWER switch. When the power is turned off, the front panel settings are retained so that the instrument will return to the same settings when the power is next turned on. -
Page 17: Rear Panel
SR510 Guide to Operation Rear Panel AC Power The ac line voltage selector card, line fuse, and line cord receptacle are located in the fuse holder at the left side of the rear panel. See the section, Preparation for Use at the front of this manual for instructions on setting the ac voltage selector and choosing the correct fuse. - Page 18 OUTPUT can be set to three amplitudes, 1 V, 100 mV, and 10 mV (rms) using the amplitude switch. The output impedance is 600 . The AMP CAL screw adjusts the amplitude. The oscillator frequency is controlled by the VCO INPUT voltage.
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Page 19: Communications
Communications with the SR510 use ASCII characters. Commands to the SR510 may be in either UPPER or lower case. A command to the SR510 consists of one or two command letters, arguments or parameters if necessary, and an ASCII carriage return (<cr>) or line-feed (<lf>) or both. -
Page 20: Rs232 Echo Feature
RS232 Echo and No Echo Operation In order to allow the SR510 to be operated from a terminal, an echo feature has been included which causes the unit to echo back commands received over the RS232 port. -
Page 21: Command List
SR510 Command List The first letter in each command sequence is the command. The rest of the sequence consists of parameters. Multiple parameters are separated by a comma. Those parameters shown in {} are optional while those without {} are required. - Page 22 J {n1,n2,n3,n4} The J command sets the RS232 end-of-record characters sent by the SR510 to those specified by the ASCII codes n1-n4. If no argument is included, the end-of-record sequence returns to the default (a carriage return), otherwise, up to four characters may be specified.
- Page 23 SRQ mask is returned. W {n} The W command sets and reads the RS232 character wait interval. If n is included, the SR510 will wait n*4 mS between characters sent over the RS232 interface. This allows slow computer interfaces to keep up.
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Page 24: Status Byte
The definitions for each bit of the status byte are given below: Bit 0 Busy. When this bit is set, it indicates the SR510 has unprocessed commands pending on its command queue. For RS232 communications, this bit is always high since the Y command itself will be an unprocessed command. -
Page 25: Trouble-Shooting Interface Problems
3) eavesdrop on transactions when using the RS232 interface, 4) substitute a human for the SR510 by using a null modem cable ( to make the DTE a DCE ) and attaching the terminal to the port to which you would normally have connected the SR510. -
Page 26: Data Communications Equipment
Data Communications Equipment (DCE) The SR510 is configured as DCE so that it may be connected directly to a terminal. If the SR510 is to be interfaced with another DCE device, a special cable (sometimes referred to as a 'modem' cable) is required. -
Page 27: Serial Polls And Srq's
RS232 interface would never be enabled. Serial Polls and Service Requests The status byte sent by the SR510 when it is serial polled is the same status byte which is read using the Y command (except for bit 6, SRQ). Of course, when the SR510 is serial polled, it does not encode the status byte as a decimal number. -
Page 28: Measurement Example
The Lock-in Technique The Lock-in technique is used to detect and measure very small ac signals. A Lock-in amplifier can make accurate measurements of small signals even when the signals are obscured by noise sources which may be a thousand times larger. Essentially, a lock-in is a filter with an arbitrarily narrow bandwidth which is tuned to the frequency of the signal. -
Page 29: Understanding The Specifications
Understanding the Specifications The table below lists some specifications for the SR510 lock-in amplifier. Also listed are the error contributions due to each of these items. The specifications will allow a measurement with a 2% accuracy to be made in one minute. -
Page 30: Dynamic Reserve
(as is the case here) the noise picked up by the shield will also appear on the center conductor. This is good, because the lock-in's 100 dB CMRR will reject most of this common mode noise. However, not all of the noise can be rejected, especially the high frequency noise, and so the lock-in may overload on the high sensitivity ranges. -
Page 31: Notch Filters
0.5Hz to 100KHz. No additional cards are required for the instrument to cover its full frequency range. The SR510 can be used to detect a signal at the reference frequency or at twice the reference frequency to allow for convenient measurement of the harmonic of the signal. -
Page 32: Sr510 Block Diagram
SR510 Block Diagram Several new concepts are used to simplify the design of SR510 lock-in amplifier. In addition to implementing recent advances in linear integrated circuit technology, the instrument was designed to take full advantage of its microprocessor controller to improve performance and to reduce cost. -
Page 33: Signal Channel
Each unit is computer calibrated at the factory, and calibration constants are placed in the instrument's read-only memory. The SR510 has only one-fifth of the analog trimming components that are found in older designs. Creative programming on the user's part can extend the instrument's capabilities. -
Page 34: Circuit Description
This discussion is intended to aid the advanced user in gaining a better understanding of the instrument. The SR510 has 8 main circuit areas: the signal amplifier, the reference oscillator, the demod- ulator, the analog output and controls, the front panel, the microprocessor, the computer inter- faces, and the power supplies. -
Page 35: Reference Oscillator
reference frequency is converted into a current by 1/4 U208 and Q201. This current programs the effective "resistance" of the two transconductance amplifiers and thus, tunes the center frequency of the filter to follow the reference. The output of the filter is buffered by 4/4 U201. -
Page 36: D/A's
is sampled and held on capacitor C502 and buffered by 4/4 U508. The A/D conversion is done by successive approximation using comparator U514 to compare the sampled and held signal with known outputs of U505, a 12 bit DAC with a precision reference. -
Page 37: Power Supplies
whenever a GPIB transaction occurs which requires the CPU’s response. (The GPIB address is set by switch bank SW1.) Power Supplies The line transformer provides two outputs, 40VAC and 15VAC, both center -tapped. The transformer has dual primaries which may be selected by the voltage selector card in the fuse holder. -
Page 38: Calibration And Repair
Calibration and Repair This section details calibration of the instrument. Calibration should only be done by a qualified electronics technician. ********** WARNING ********** The calibration procedure requires adjusting the instrument with power applied and so there is a risk of personal injury or death by electric shock. Please be careful. -
Page 39: Line Notch Filter Adjustment
Notch Filters Set the reference frequency to 60.0 Hz (50.0 Hz). It is convenient to use the SYNC output of the signal generator as the reference input if it is available. Connect the sine output of the signal generator to the A input and set the input selector to A. -
Page 40: Appendix A: Noise Sources And Cures
Appendix A: Noise Sources and Cures Noise, random and uncorrelated fluctuations of electronic signals, finds its way into experiments in a variety of ways. Good laboratory practice can reduce noise sources to a manageable level, and the lock-in technique can be used to recover signals which may still be buried in noise. -
Page 41: Capacitive Coupling
400pA. This meager current is about 4000 times larger than the most sensitive current scale that is available on the SR510 lock-in. Cures for capacitive coupling of noise signals include: 1) removing or turning off the interfering noise... -
Page 42: Ground Loops
Resistive Coupling (or 'Ground Loops'). Currents through common connections can give rise to noise voltages. Resistive Coupling Here, the detector is measuring the voltage across the experiment, plus the voltage due to the noise current passing through the finite resistance of the ground bus. -
Page 43: Using Control Lines
As an example, consider connecting an RS232 ASCII computer terminal to the SR510 using a 2 wire link. The terminal is a DTE and the SR510 is a DCE. To operate correctly, the SR510 and the terminal must have the same settings for baud rate, parity, and number of stop bits. -
Page 44: Stop Bits
To use as a debugging tool, attach the hook clip to either pin 2 or pin 3 of the RS232 cable on the SR510 to show either data sent from the Computer or the SR510. -
Page 45: Introduction To The Gpib
Appendix C: Introduction to the GPIB The IEEE-488 Standard specifies the voltage levels, handshake requirements, timing, hardware details, pinout and connector dimensions for a 16 line, bit parallel bus. Many instruments may be connected in series to communicate over the same cable. -
Page 46: Appendix D: Program Examples
5,6,8 and 20 should be connected together on the connector at the IBM end. 10 ′ EXAMPLE PROGRAM TO READ THE SR510 OUTPUT AND RAMP THE X6 ANALOG OUTPUT 20 ′ USING IBM PC BASICA AND THE COM1: RS232 PORT. - Page 47 *20 str1,str2 Example program to read the SR510 outputs and ramp the X6 analog output using Microsoft FORTRAN v3.3 and the COM1: port. Set all switches in SW2 to UP on SR510 for 19.2 kbaud. initialize COM1: port to 19.2 kbaud...
- Page 48 print results to screen write(*,2000) v1 format(′ Output 1=′,G10.3) 2000 ramp x6 by 2.5 mV x6 = x6 + .0025 if (x6.gt.10) x6 = 0.0 make x6 command string write (str2,3000) x6 3000 format (′x6,′,f7.3,′$′) call txstr(str2) and loop forever goto 20 stop ***********************************...
- Page 49 If an error occurs, your procedure nocom() is called. Nocom() must be a C procedure in your program. Example program to read the SR510 outputs and ramp the x6 analog Output using Microsoft C v3.0 (large model) and the COM1: port.
- Page 50 x += 0.0025; if (x >= 10) x = 0; sprintf (str2, ″X6,%f$″, x); txstr (str2); /* print results to screen */ printf (″Output = %10.36\n″, v1); /* ********************************************* */ nocom () /* error handling routine goes here */ printf(″RS232 Timeout Error\n″); putch (7);...
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Page 51: Ibm Pc, Microsoft Basic, Via Gpib
30 ′ 40 ′ 50 ′ ON THE SR510 REAR PANEL, SET SWITCHES #4 AND #6 ON SW1 TO DOWN (DEVICE 60 ′ ADDRESS = 23, RS232 ECHO ON) AND SWITCH # 1 ON SW2 TO DOWN (RS232 BAUD 70 ′... - Page 52 390 CALL TRANSMIT (X$,STATUS%) 400 GOSUB 540 410 ′ ′LOOP FOREVER 420 GOTO 280 430 ′ 440 ′ GET AN ANSWER STRING FROM THE SR510 450 CALL TRANSMIT(LISN$,STATUS%) ′MAKE SR510 A TALKER 460 GOSUB 540 470 ANS$=SPACE$(10) 480 CALL RECV(ANS$,LENGTH%STATUS%) 490 GOSUB 540 500 RETURN 510 ′...
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Page 53: Hp-85, Hp Basic, Via Hpib
This program provides an example of an HP85 program using the GPIB interface which could be used to control the lockin amplifier. In this example, the SR510 should be addressed as device #16 by setting the switch bank SW1 per the instructions Page 7. -
Page 54: Documentation
Documentation This section contains the parts lists and schematics for the SR510 lock-in amplifier. The first digit of any part number can be used to locate the scematic diagram for the part. For example, R415 is located on sheet 4 of... -
Page 55: Parts List, Main Assembly
C 209 5-00109-525 C 210 5-00048-566 C 211 5-00051-512 C 212 5-00055-512 C 213 5-00060-512 SR510 PARTS LIST VALUE DESCRIPTION KBP201G/BR-81D Integrated Circuit (Thru-hole Pkg) KBP201G/BR-81D Integrated Circuit (Thru-hole Pkg) BR-2/3A 2PIN PC Battery Capacitor, Mylar/Poly, 50V, 5%, Rad Capacitor, Mylar/Poly, 50V, 5%, Rad... - Page 56 5-00052-512 C 407 5-00052-512 C 408 5-00003-501 100. C 409 5-00056-512 SR510 PARTS LIST VALUE DESCRIPTION .47U Cap, Stacked Metal Film 50V 5% -40/+85c 1.0U Cap, Stacked Metal Film 50V 5% -40/+85c Cap, Stacked Metal Film 50V 5% -40/+85c Capacitor, Electrolytic, 50V, 20%, Rad Capacitor, Electrolytic, 50V, 20%, Rad .15U...
- Page 57 5-00052-512 150. C 712 5-00052-512 151. C 713 5-00014-501 SR510 PARTS LIST VALUE DESCRIPTION Cap, Stacked Metal Film 50V 5% -40/+85c Cap, Stacked Metal Film 50V 5% -40/+85c Cap, Stacked Metal Film 50V 5% -40/+85c .001U Cap, Polyester Film 50V 5% -40/+85c Rad .033U...
- Page 58 5-00100-517 200. CN801 1-00014-160 201. CN802 1-00016-160 202. CN803 1-00238-161 SR510 PARTS LIST VALUE DESCRIPTION 390P Capacitor, Ceramic Disc, 50V, 10%, SL 330P Capacitor, Ceramic Disc, 50V, 10%, SL 330P Capacitor, Ceramic Disc, 50V, 10%, SL 330P Capacitor, Ceramic Disc, 50V, 10%, SL .01U...
- Page 59 3-00026-325 249. Q 502 3-00026-325 250. Q 701 3-00026-325 251. Q 702 3-00026-325 252. Q 703 3-00026-325 253. R 101 4-00033-404 SR510 PARTS LIST VALUE DESCRIPTION 4.000 MHZ Crystal 1N4148 Diode 1N4148 Diode 1N4148 Diode 1N4148 Diode 1N4148 Diode 1N4148...
- Page 60 302. R 159 4-00141-407 303. R 160 4-00033-404 304. R 161 4-00204-407 SR510 PARTS LIST VALUE DESCRIPTION 100M Resistor, Carbon Comp, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% 1.00K Resistor, Metal Film, 1/8W, 1%, 50PPM 6.81K...
- Page 61 R 304 4-00045-401 354. R 305 4-00032-401 355. R 306 4-00021-401 SR510 PARTS LIST VALUE DESCRIPTION 4.99K Resistor, Metal Film, 1/8W, 1%, 50PPM Resistor, Carbon Film, 1/4W, 5% Resistor, Metal Film, 1/8W, 1%, 50PPM Resistor, Metal Film, 1/8W, 1%, 50PPM...
- Page 62 404. R 356 4-00160-407 405. R 357 4-00163-407 406. R 358 4-00034-401 SR510 PARTS LIST VALUE DESCRIPTION Resistor, Carbon Film, 1/4W, 5% Resistor, Metal Film, 1/8W, 1%, 50PPM 330K Resistor, Carbon Film, 1/4W, 5% 1.0K Resistor, Carbon Film, 1/4W, 5% 1.0K...
- Page 63 4-00146-407 455. R 430 4-00140-407 456. R 431 4-00032-401 457. R 432 4-00021-401 SR510 PARTS LIST VALUE DESCRIPTION 2.0K Resistor, Carbon Film, 1/4W, 5% 100K Resistor, Carbon Film, 1/4W, 5% 5.1K Resistor, Carbon Film, 1/4W, 5% 32.4K Resistor, Metal Film, 1/8W, 1%, 50PPM 1.10K...
- Page 64 4-00054-401 506. R 549 4-00032-401 507. R 701 4-00031-401 508. R 702 4-00079-401 SR510 PARTS LIST VALUE DESCRIPTION 1.0K Resistor, Carbon Film, 1/4W, 5% 1.0M Resistor, Carbon Film, 1/4W, 5% 1.0M Resistor, Carbon Film, 1/4W, 5% 1.0M Resistor, Carbon Film, 1/4W, 5% 1.0M...
- Page 65 557. U 114 3-00076-340 558. U 115 3-00089-340 559. U 117 3-00088-340 SR510 PARTS LIST VALUE DESCRIPTION 1.5K Resistor, Carbon Film, 1/4W, 5% 1.0K Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% 300K...
- Page 66 U 411 3-00126-335 608. U 412 3-00126-335 609. U 413 3-00126-335 610. U 414 3-00126-335 SR510 PARTS LIST VALUE DESCRIPTION 5532A Integrated Circuit (Thru-hole Pkg) LF347 Integrated Circuit (Thru-hole Pkg) LM13600 Integrated Circuit (Thru-hole Pkg) CD4052 Integrated Circuit (Thru-hole Pkg)
- Page 67 658. U 803 3-00044-340 659. U 804 3-00044-340 660. U 805 3-00049-340 661. U 806 3-00109-340 SR510 PARTS LIST VALUE DESCRIPTION 51A05 Relay ICL7650 Integrated Circuit (Thru-hole Pkg) 51A05 Relay DG211 Integrated Circuit (Thru-hole Pkg) LF411 Integrated Circuit (Thru-hole Pkg)
- Page 68 707. 0-00228-052 708. 0-00231-043 709. 0-00233-000 710. 0-00241-021 711. 0-00249-021 712. 0-00256-043 SR510 PARTS LIST VALUE DESCRIPTION MC1489 Integrated Circuit (Thru-hole Pkg) DS75160A Integrated Circuit (Thru-hole Pkg) 78L12 Transistor, TO-92 Package 79L12 Transistor, TO-92 Package DS75161A Integrated Circuit (Thru-hole Pkg)
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Page 69: Parts List, Internal Oscillator
R 10 4-00186-407 R 11 4-00022-401 R 12 4-00042-401 R 13 4-00070-401 R 14 4-00034-401 SR510 PARTS LIST VALUE DESCRIPTION 4-40X3/16PF Screw, Black, All Types 554808-1 Hardware, Misc. 3" #18 Wire, #18 UL1015 Strip 3/8 x 3/8 No Tin 10-1/2" #18... -
Page 70: Parts List, Miscellaneous
0-00247-026 0-00248-026 0-00371-026 6-00054-611 7-00147-720 7-00198-720 7-00199-720 7-00200-720 7-00203-720 SR510 PARTS LIST VALUE DESCRIPTION 1.0M Resistor, Carbon Film, 1/4W, 5% 4.7K Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% 4.99K... -
Page 71: Parts List, Front Panel
DS635 3-00012-306 DS636 3-00012-306 DS637 3-00012-306 DS638 3-00013-306 SR510 PARTS LIST VALUE DESCRIPTION Capacitor, Ceramic Disc, 50V, 10%, SL Capacitor, Ceramic Disc, 50V, 10%, SL .01U Cap, Stacked Metal Film 50V 5% -40/+85c .01U Cap, Stacked Metal Film 50V 5% -40/+85c... - Page 72 PB618 2-00001-201 PB619 2-00001-201 PB620 2-00001-201 PB621 2-00001-201 PB622 2-00001-201 PB623 2-00001-201 100. PB624 2-00001-201 SR510 PARTS LIST VALUE DESCRIPTION LED, Rectangular LED, Rectangular GREEN LED, Rectangular GREEN LED, Rectangular GREEN LED, Rectangular GREEN LED, Rectangular GREEN LED, Rectangular GREEN...
- Page 73 138. 1-00145-131 139. 7-00294-710 140. 7-00308-709 141. 9-00554-913 142. 9-00815-924 SR510 PARTS LIST VALUE DESCRIPTION D6-01-01 Switch, Momentary Push Button SR511 Printed Circuit Board Resistor, Carbon Film, 1/4W, 5% Resistor, Carbon Film, 1/4W, 5% 22KX7 Resistor Network SIP 1/4W 2% (Common)