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Содержание 128A

Страница 1: ...MODEL 128A LOCK IN AMPLIFIER SEE SAFETY NOTICE PRECEDNG SECTION I EFORE OPERATING INSTRUMENT OPERATING AND SERVICE MANUAL...

Страница 2: ...M128A 9 83 500 MIC MODEL 128A LOCK IN AMPLIFIER OPERATING AND SERVICE MANUAL n G BROOKDEAL ELECTRONICS I PRINCETON APPL ED RESEARCH Copyright 1983 EG G PRINCETON APPLIED RESEARCH Printed In U S A...

Страница 3: ...se price at our option of any instrument returned freight prepaid to our factory within ONE year of delivery to the original purchaser provided prior authorization for such return has been given by ou...

Страница 4: ...th the Internal Reference Oscillator 4 7 A Introduction 4 7B Operation 4 7C Installation 4 8 Operation with the Internal Tuned Amplifier 4 8A Introduction 4 8B Operation 4 8C Installation 4 9 More Ref...

Страница 5: ...ong Errors Depicted in Figure IV 4 Corrected Typical Model l28A Noise Figure Contours Pulse Train as Reference Drive Net Phase Shift Between Signal and Reference Channels as a Function of Frequency Am...

Страница 6: ...nd contact The protective action must not be negated by the use of an extension cord without a protective conduc tor or by use of an adapter that doesn t main tain earth ground continuity or by any ot...

Страница 7: ...set the HI PASS and LO PASS Filter switches as required Connect the signal source to the Model 128A Input 1 1 gone For this reason it is advisable to read Section IV the complete Operating Instruction...

Страница 8: ...1 2 a w u Q c 0 t co N W 0 i e l u...

Страница 9: ...calibrated zero suppression of up to 10 x full scale a two position dc prefilter and the capability of driving the reference input the detector at double the frequency of the signal applied to the Re...

Страница 10: ...is better than 0 2 0 over the entire frequency range The resolution of the dial is better than 0 1 0 The incremental phase shiffs provided by the Quadrant switch are accurate to 0 2 The overall phase...

Страница 11: ...ng of 1 Output of Signal Channel before demodulation please note that the Signal Channel monitor is provided as part of the Tuned Amplifier modification as well 2 Squarewave output of Reference Channe...

Страница 12: ...r position 111 1 dial 1 00 one turn from fully counterclockwise position Time Constant 3 SEC DC Prefilter OUT Reference Tracking Rate switches two internal switches FAST unless unit is equipped with T...

Страница 13: ...se Quadrant switch to 270 to restore the 111 2 positive full scale panel meter indication 13 Set the Zero Offset toggle switch to The panel meter indication should go to 0 5 of full scale 14 Begin rot...

Страница 14: ...cy within the operating range of the instrument operation is simplest and least subject to error over a range having as its lower limit perhaps a few hundred Hz and as its upper perhaps 10k Hz At very...

Страница 15: ...tor is indicated as being connected between the chassis of the Model l28A and siqnal source common This path would ordinarily consist of the ac ground third wire paralleled by the braids of other cabl...

Страница 16: ...ock In Amplifier allows very large improvements in signal to noise ratio to be achieved the amount of noise contributed by the Lock In Amplifier itself affects its performance and limits the achievabl...

Страница 17: ...re than before it is only because the ampl ifier noise is now less relative to the thermal noise of the combined resistances source plus IV 4 series resistor The signal is no larger in fact it may wel...

Страница 18: ...th the result that the Reference Channel will not function properly Thus when using pulses as the reference input take care that the duration of the pulses relative to the pulse period is great enough...

Страница 19: ...the meter The absolute accuracy and resolution of the Phase controls are stated in the specifications Figure IV 8 shows the typical net phase shift through the unit Additional phase shifts are introd...

Страница 20: ...Under most conditions by setting these filters so that they bracket the signal fre I v _ _ V l V H H 7f V I OSN t t _ V _ 0 quency as closely as possible the noise tolerance of the instrument will be...

Страница 21: ...h to a good approximation Nevertheless even though the prefilter may do relatively little to further reduce the equivalent noise bandwidth if the main Time Constant setting is longer its effect in smo...

Страница 22: ...ertheless maximum output would still be at 0 and 180 0 and zero output would be obtained at 90 0 and 270 It might be mentioned that the waveforms illustrated in Figure IV 12 apply only at frequencies...

Страница 23: ...quired one to supply 24 V 300 mAl and the other to supply 24 V 300 mA The 24 V source should be connected to pin 7 The 24 V source should be connected to pin 5 Ground for both is at pin 1 It is genera...

Страница 24: ...is connected to J419 The wh ite orange wire is connected to J420 and J418 is not used Also the two frequency determining capacitors should be removed when operating with an external reference source...

Страница 25: ...anel connector to the Oscillator bo quick disconnect contacts as shown in Figure IV Th is completes the installation The top and bottom CD may now be reinstalled To check the oscillator sim turn on th...

Страница 26: ...a dial 90 0 function of the value of the two replaceable capacitors is Time Constant 3 SEC the same as for the Internal Reference Oscillator Also the Zero Offset OFF dial setting irrelevant restricti...

Страница 27: ...one could use a digital voltmeter connected to the front panel OUT connector 11 Adjust the Model 128A GAIN CAL trim poten tiometer R143 for exactly full scale panel meter indication 1 000 V on a DVM...

Страница 28: ...shell of the connector and chassis ground Then connect the orange wire attached to the connector to pin J128 rear edge of Signal Amp Bd and the black wire to J121 Current production units use a differ...

Страница 29: ...NEL ONLY TO AVOID ELECTRIC SHOCK DO NOT PERFORM ANY SERVICING UNLESS YOU ARE QUALIFIED TO DO SO ANY ADJUSTMENT MAINTENANCE AND REPAIR OF THE OPENED APPARATUS UNDER VOLTAGE SHALL BE AVOIDED AS FAR AS P...

Страница 30: ...to be in phase The fixed output is used as the reference drive to the lock in amplifier and need not be a sinewave One suitable oscillator would be the Krohn hite Model 4200 One could also use a sing...

Страница 31: ...OUT RI43 GAIN PREAMP OUT ClOG HF CMR SYM ADJ i 1 i REF BO FINAL AC AMP OUT 2 J232 FINAL AC AMP OUT 1 J 231 MIXER POWER SUPPLY BO TP202 R20l AC BAL C210 HF ZERO TP201 R234 AMP 1 ZERO o 0 R242 A2 ZERO...

Страница 32: ...two jumpers connected in steps 1 and 2 5 Select for R273 that resistor which yields a DVM indication of 0 0 2 mV The resistor value should be one megohm or smaller 2 DC Amp 1 Zero Adj R234 a Set the S...

Страница 33: ...to Then rotate the Zero Offset dial to the fully clockwise position c Adjust R243 Zero Offset Cal for 0 00 V on the DVM The panel meter will also indicate 0 d Set the Zero Offset Polarity switch to OF...

Страница 34: ...hile the signal applied to the Signal Input connector is taken from the junction of the two divider resistors b Set the signal frequency to 100 kHz and adjust the signal source output amplitude so tha...

Страница 35: ...A SKILLED PERSON WHO IS EXPERIENCED IN WORKING ON ELECTRONIC APPARATUS AND WHO IS AWARE OF THE HAZARD NVOLVED WHEN THE INSTRUMENT IS CON NECTED TO A POWER SOURCE TERMINALS MAY BE LIVE AND THE OPENING...

Страница 36: ...of a series of procedures to be 15 V regulators Thus any trouble with the 15 V followed in troubleshooting the Model 128A The purpose regulator would cause loss of regulation in the 15 V of the proce...

Страница 37: ...ed signal should be a srnewave with a pk pk amplitude of 2 8 V indicatinq that the preamplifier has the expected gain of ten VI 2 6 6B INTERMEDIATE AC AMPLIFIERS schematic on page VII 4 1 Connect the...

Страница 38: ...V assuming the input signal is the specified amplitude Also the panel meter should indicate full scale If readinqs other than those indicated are obtained the trouble is associated with the final de a...

Страница 39: ...s eliminated A plate TUNED FREQUENCY ADJUST SYMBOLIZATION MODEL 129A 84 TUNED AMPLIFIER MODIFI CATlON BOARD FAB IF 6973 MD A OSCILLATOR FREOUENCY ADJUST AMPLITUDE ADJUST SYMBOLIZATION MODEL 129A 95 MO...

Страница 40: ...EO WITHOUT _I CONSENT Of THE PRINCETON IEO MCH COllI R719 IK 1 0 A 718 14K I MOREL 128 R 715 K S 0 r o I I 15V R72 Ion 50 0 1O 5V M 71 10k 1 IO SV 6 LK AEl r J If J if J Ifi _ l0 1 8 Q J P 725 Ion 5 0...

Страница 41: ...OOUCED WITHOUT WfuTTtN CONSENT aF THE PRINCETON APPLIED Mat ex t R 25 300n 5 Q 02 T1S9Z R 24 15K 59 0 R 62 3 15K 5 MODEL 128 151 R 622 9 09K 15 1 15 1 R 20 402 c o l uf R W I 16 4 IK n 4MPLlTuOf V 40J...

Страница 42: ...tch on the rear panel of the modified Model 128A or Model 129A to the SELECTIVE position B 1 3 Connect a cable from the Model 189 INPUT conneotor to the TO M189 IN connector on the rear of the lock in...

Страница 43: ...cs is attempted B 2 EXTRA GAIN OF TEN OPERATION The Model 189 has a gain of one when both of the Model 189 GAIN pushbuttons are in the out posi tion The maximum sensitivity that can be select ed at th...

Страница 44: ...E L 1 ____ _N J I0 6 JI07 l l TO IIlxER BCARQ I J6 HlO f L 1 tg m r 61e CONNECT TO J418WHEN OPt REf OSC 15 USED JS r1 R R OPTI HAL Jill Jl J4Z1 IS r76 I IS t 7S I S 4r 7 e 15V IZ II I M 1ST DC AMPl Pl...

Страница 45: ...S0 sheet 2 of 2 Mixer Power Supply Board Parts Location ixer PowerSupply Board 7444 0 S0 sheet 2 of 3 ixer PowerSupply Board 7444 0 S0 sheet 3 of 3 assis Wiring Diagram 7589 E SO ternal Oscillator Bo...

Страница 46: ...01 xl 4 C I 0 A 00 Rx 1 _ crct crcr R121 w o o wr R165 Cll1 1 D ex I H I tf fIft IO ff im t f r fS1t I 0111 C1 5101 8 C116 5 Hz HI PASS 50 Hz HI PASS 1 kHz LO PASS I D It 0 I It tttt tL III S101 E 510...

Страница 47: ...TSI I g r h EAOO H F C R oro e I J 02 3 PA S Tf I RIO I I OM I 3v I 22 r l U I 7 is TP O SP C NO A f o 100 R O_ RIIO 0106 20x K JilllS teen 1 J L M I on I CR O_ 103 T I IOOnF PAR IOOnf J O __ J SPEC C...

Страница 48: ...LI I r HI o zSS SElW O L1f E I I I L SOCKET I 1 n ri I rf n frhl l i iT 1 rr lJIIO_ JII7 JIIZ JII6 _m l34 J lJ 30 JIZ9 J ZO JII9 JII8 _ JI3 JISZJ lJ z J l8 J 23 J lZJ l4 J H J 26 J 27 IIJI27 10 Jll7 I...

Страница 49: ...R454 Q sr I T P 407 Q427B v 111 CR40 402 f W R4 53 04315 1 Q425A 5 v0423 0429 CR41 1 5401 11m 0 T T a 0 U405 NIT P U406 fuR451 5 rt1 I 0 N v T10 2 r r 403 D m R517 7 1 1col 1 1101 1 11101U v v V N q I...

Страница 50: ...41 In 2 V R4S0 OK MODEL 128 8A R517 0011 I 15 f A42 ZOK l 27 i SfE NOTE 3 L v R426 0 I I I 5 t l t R ZZ R 23 91O fl 1 422 5v SHT 2 A4S 2 R 2 r2 K 0 s 40 SHEETl R 200n u P CAIIIOJ TP 0 o 4 5V 15V Ij ll...

Страница 51: ...t SHT2 0F2 1E 6221 o S0l 15 OA A S09 NOTES TO U_06 SI1EET I Asoe 0 4 10K 90 0 180 2701 MODEL i2iH i28A RS04 io 99K _ 00 99 1 llJk 49 OOK t R4 7 4 1 1 lf l f S Oi TO TO R4SZ R4S SC 5tH iIoiT I CA I IN...

Страница 52: ...5V D It If J312 Q308 it 0 Wr R317 R R318 wr C311 Q3050304 l u 1 R 10 15V ADJ 5 If J241 CR214 I U 2 1 t 1 J227 R268 T CR202 cR 1 R263 ll W 14CR215 w R264 CR216 R267 f R282 TP203 J207 J220 J226 J211 J21...

Страница 53: ...0 CIRe U I T SEE ShEET 2 OF 3 NOTES P 2El9 26 7K IOjb RZElS 10 I R2641R282 101 10 K C22I IOnF R266 26 7K R263 3901 OL SENSE CZ20 l TO IOn F J228 TO 5IG 2 l 1 4V J229 1 1 J227 TO SIG BD __I I r1 4V OL...

Страница 54: ...EL 128A AZ Z17 ol A245 1 1 I METEA r cZ JZ l I 70p I 00n 7 I I S sV I RZJ9 10M I VZW TO NTER ACE CONN A ZJe 3S 1K I ll A237 49 91 ZS I4 1 5 15 V 1l 5V IS V 5 0V NO D C AMPL J R216 49 9K ZS A23S M I ti...

Страница 55: ...i J 30 Z swl L f j17J J R314 r51J Tl Iz 15V 6 0 A 11 eK ule Clit 68K 100 R316 Ok NOTE S W SV POwE s PPt y R31S Z k MOOC L 128 All 20 IC JIb VZW R 109 I I K ti 303 5 M Z ClIf OI 5 19V lJ06 IOk 2 1 R301...

Страница 56: ...J J11 fo R R R OPTI NAl J 15V rt 1 r 1 Jt 9 JI26JIl5 i1 1 4 WIRE flAT A1880H CABLE iC sWrnTCH lAMP P J U J t J O M 59 cPiJl te FF ON 1 TI I t 41 I IO lffi IEmJ R J MODEL 28A 17589 E sDi VII 12...

Страница 57: ...19 R628 W hl t 624 Nf R621 1 R62 Q60 CD Vy 11 R 26k no I k m CR605 0Y f R612 eRtr Thh m RGt8 J R622 1 Q2 R620 ocx I en D a R601 0 000 It 0 D D D D D 0 y i lP lf fir Y 0 _ _ J t u SYMBOLIZATION MODEL 1...

Страница 58: ...PMENT AND IS NOT TO BE USED OTHERWISE OR REPRODUCED WITHOUT WRITTEN CONSENT OF THE PRINCETON APPLIED RESEARCH CORP CRf 05 IN48Z8 015VDC I 3 R 623 15K 5 MODEL 128 15V 4I I 15V I R 622 9 09K 2 5 3V 128...

Страница 59: ...o R 3 N i 0 Wr R705 t o R706 C70T R708 A R702 Ir R7278 TUNED FREQUENCY ADJUST R719 AU 2 f o R703A R70 III 0 0 t t iJ 701 o to rtl l 8 i lE C709 E 1 Q 7 03 w R70 9 0 tt B716 1 Q704 fR720 Q70 Q707 j7 fi...

Страница 60: ...ONSENT OF THE PRINCETON APPLIED RESEARCH CORP R719 IK I ero R718 14K 1 I S702 MODEL 128 I 15V i t R726 Ion 50 0 6 tEL 15V R712 10K 1 5 IO 5V 15V RED iJ f J f J fl L_ IO I Q B Q J R725 on 50 0 R709 10K...

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