Keithley 445 Instruction Manual Download Page 4

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Summary of Contents for 445

Page 2: ...DESCRIPTION 2 PEmTION _ _ _______________I____ 3 CIRCUIT DESCRIPTION __ _ 4 p LE PARTS ________________ _____I________ _ 5 C TBmTl N __ ______ __ __ SCHEMATICS __ _ _ __ ______ll______l_____ PM 2 ii 1...

Page 3: ...Hold Diagram 15 Integrator Block Diagram 15 zero cro ing DetacLor 15 Model 4401 Buffer stage 17 Chassis Top View 19 PC Board Locationa 20 Componanr Layout PC 207 21 cMnponenc Layout PC 208 21 COmponen...

Page 4: ...s ANALOG OUTPUT tl volt from 500 ohm sourc for full scale display Maximum output 1 millian per Output polarity is opposit input polarity PRINTER OUTPUTS AN0 REMOTE CONTROLS Printer Output SCD positive...

Page 5: ...erload Protection A transient overload of g Complete BCDOutput and Control Lines Binary 1000 volts at up to 20 r A will not damage the instru Coded Decimal Outputs are provided on a rear panel nlent c...

Page 6: ...Front Panel Controls TABLE 1 2 Rear Panel Terminals Terminal INPUT Receptacle 51213 LO Binding Post 51215 GNDBinding Post 51217 PRINTER CONTROL Connector 51214 ANALOG OUTPU I 51218 Functional Descript...

Page 7: ...MODEL 445 OPERATION SECTION 2 OPERATION 1NPUT LOW HIGH CASE...

Page 8: ...various time intervals which co etitute the total reading time are described es follows The intervals are graphically shown in Figure 5 1 T1 A D Conversion Time until first range change 2 T2 Total Ti...

Page 9: ...ange is reached that 10 9 10 q g DISPLAY RATE R12371 This control adjusts the A D Converter conversion rate from 24 readingslsec MAX to 1 reading Z sec approx 2 4 OPERATINGPROCEDURE a Preliminary Prac...

Page 10: ...sion at that iridtant Hold 82 Closure to ground inhibits A to D canver sion after reading has been completed Trigger Closure to ground initiates one conversior when in Hold 112 Integration period star...

Page 11: ...ponding to 1 000 o any range Since this output has a source resistance of 499 ohms the recording device must have a load resistance greater than 10 kilohms to obtain 1 000 volt for full range If a re...

Page 12: ...out puts are final readings No change can take place except Zero Check for 25 milliseconds This Print Command signal is present regardless of the mode ADTOMATICor HOLD PRINT COMMAND 8 This control is...

Page 13: ...__ ___ ___ ___ ___ Remote Zero Check Remote w2 Remote Range Hold _ Print Command A Hi Reference Law Reference Pin No Output 26 4 x 100 27 8 x 100 28 29 4 8 x x 101 101 30 4 x 102 31 8 x 102 32 Comon 3...

Page 14: ...cle Timing The Conversion Conversion Cycle Timing The Conversion Cycle is composed of three timing periods namely Cycle is composed of three timing periods namely Integrator Zero Integrator Sampling a...

Page 15: ...is determined by the RANGEresistor connected across the feedback The RANGgresistance RP is composed of a fixed resistance 81 plus a calibration adjustment resistance K2 as shown in Figure 11 The RANG...

Page 16: ...100 and 1000 e Delay Hold The Delay Hold circ it controls the DISPLAY BATE function and external Hold and Trigger commandsas shown in Figure 14 It determines ehe length of time between A D conversion...

Page 17: ...1...

Page 18: ...CONVERTER...

Page 19: ...or circuit provides a High or Low level out put depending on the polarity of the detected input Refer to Table 3 l for e description of voltage out puts TABLE 3 l Zero Crossing Detector Output Levels...

Page 20: ...CIRCUITRY a General The circuits described in this aectio are located on the various Sub Assemblies listed beloh and in Table 7 2 of Section 7 1 Oscillator Board K 217 2 Integrator Board K 219 3 Displ...

Page 21: ...trols the Numerical Blanking circuit and provides an Overload Print eiglL l e Readout Board The Readout Board contains Dec ade Counter circuits Buffer Storage clrwlts and Decoder Driver and Display cl...

Page 22: ...e output cur rent COabout 200 milliamperes b C3 6 Volt Supply The 3 6 volt supply taps ac power from a secondary of transformer TlOl Diodes DlOl and D102 and capacitor Cl01 farm a full wave rec tifier...

Page 23: ...MODEZ 445 SERVICING FIGURE 18 Chassis Top View...

Page 24: ...SERVICING MODEL 445 FIGURE l 9 PC Board Locations 20 0971...

Page 25: ...MODEL 445 DIGITAL PICOAMKETER SERVICING FIGURE 20 Component Layout PC 20 I TP S ape Trigger I FIGURE 21 Component Layout PC 208 0171 21...

Page 26: ...SERVICING MODEL 445 DIGITAL PIC WMETER FIGURE 22 component Layout PC 209 FIGURE 23 component Layout PC 212 22 0171...

Page 27: ...MODEL 445 DIGITAL PICOAMMETER SERVICING FIGURE 24 Component Layout PC 214 FIGURE 25 Component Layout PC 217 0171 23...

Page 28: ...SERVICING MODEL 445 DIGITAL PICOAMMETER FIGURE 26 Component Layout PC 218 FIGURE 27 component Layout PC 219 24 0171...

Page 29: ......

Page 30: ...MODEL 445 DIGITAL PICOAMMETER SERVICING FIGURE 29 Component Layout PC 229 FIGURE 30 Component Layout PC 230 0171 27...

Page 31: ......

Page 32: ...cuits as discussed in Section 3 Refer to Table 4 2 which identifies all schematic part numbers in cluded 4 3 HOW TO SE THE REPLACEABLE PARTSLIST This Parts List is arranged such that ehe individual ty...

Page 33: ...y Polarity Board Thousand Board Readout Board 08cillator Board Integrator Board Range Control Board Range Counter Decoder Tube Driver Board Output Buffer Board Output Buffer Board MEIF Chsssis PC 221...

Page 34: ...escription Quantity Per Assembly Keithley Part No 1 Top Cover Assembly Cover 2 Fastener Bottom Cover Assembly Cover Fastener Angle Rack Assembly Screw Slotted 10 32 x l 4 Front Panel Chassis 17958C 17...

Page 35: ...s I j...

Page 36: ...ly 71590 CPR 3600J Cl38 3600P 28 Cl214 22 PF 500 POlY 71590 CPR 22J C138 22P 28 Cl215 10 PF 500 Poly 71590 cm 1O T C138 IOP 28 CU 16 Ol pF 600 cem 72982 m 01 c22 OIM 28 CONNECTORS Circuit Mfr Mfr Keit...

Page 37: ...Plug mate of 51218 Supplied 02660 SO MCZM CS 33 1 pin connector mete to I501 80164 CS 185 lx 185 FFg Ref 28 3 3 3 28 Circuit Des TYPe Mfr Mfr Keithley Fig Cade Part No PaIT NO Ref L lZOl Silicon 01295...

Page 38: ...P C Board with componenes less components Thousand P C Board with ccqmnents lceithley Part NO 23730B PC 207 22875B PC 208 2287SB PC 209 PC 212 PC 214 PC 217 PC 218 PC 219 PC 229 PC 230 Output Suffer P...

Page 39: ...WI 01686 ww 01686 MtF 07716 Mm 07716 DCb 91637 DCb 91637 DCb 91637 DCb 91637 GCb 80164 MtF 07716 C llWt 71450 wvar 71450 CetXEt 71450 CbVar 71450 COIl p 0 1121 WW X 71450 WWVU 71450 MtF 07716 CbVar 71...

Page 40: ...EAl 90201 MTVZOON35PDN Cl08 1 2 pE 20 ETT 17554 TSDl 20 125 Cl09 5 PF 600 V CerD 72982 ED 5 Cl10 125 iF 15 v ETB 73445 C42b Cl11 Cl12 Cl13 Cl14 CiX it 2000 fl 100 pF 150 pF 200 pF 200 fl 125 IF 15 pF...

Page 41: ...7716 CEA R88 1 x 28 RI05 1 kR lO l 4 W camp 44655 RCO7 R76 1K 28 R106 100 n l l S w R107 150 a l l 8 W RlOS 33 kC lO l 4 W RI09 30 l l 2 W RI10 680 a lO l 4 W MtF MtF DC COlllP 07716 CEA R88 100 28 07...

Page 42: ...8 Qlll 02734 40319 TG 50 28 q112 07263 517638 TG 33 28 Q113 07263 517638 TG 33 2s q114 07263 2N3565 x 39 28 q115 07263 2N3565 x 39 28 Q116 07263 517638 u 33 28 Q117 07263 S17638 TG 33 28 q11 02735 403...

Page 43: ...OARDPARTSLIST 300 series PC 208 Keithley Part NO TG 67 TG 67 Fig Ref 20 20 INTEGRATED CIRCUITS circuit Desig QA301 QA302 QA303 QA304 Mfr Mfr Keithley Fig Description Code Part No Part NO Ref Dual J K...

Page 44: ...UBES Mfr Keithley Fig Part NO Part NO Ref MC791P IC 9 29 MC791P IC 9 29 MC791P IC 9 29 MC79OP IC 8 29 MC790P IC 8 29 MC79OP IC 8 29 MC724P U 5 29 MC724P IC 5 29 MC79OP IC 8 29 C790P IC 8 29 MC79OP IC...

Page 45: ...ix514 470 R R515 237 n R516 1 kfl R517 4 99 kfi R518 56 kfi R519 237 0 R 520 3 3 kG R521 6 8 k0 R522 1 5 kfl R523 1 kfi R524 1 kR R525 10 kfi R526 1 kn R527 3 9 k0 R528 3 9 kR R529 330 a R530 1 5 kn...

Page 46: ...08 07263 2N5139 W 66 25 Q509 07263 2N5134 W 65 25 4510 07263 2N5134 TG 65 25 Q511 07263 2N5134 TG 65 25 Q512 07263 2N5134 TG 65 25 Q513 07263 2N5134 W 65 25 Q514 03508 2N2646 m 52 25 INTEGRATOR BOARDP...

Page 47: ...TUilZ Desig Value Rating 601 10 lin 10 l 4 W 04713 RESISTORS Mfr Type Code corn 44655 RC07 CEA CEA CEA CEA Keiehley Fig Par No Ref R76 10K 27 R88 27 R88 7 5K 27 R88 7 5K 27 R88 7 5K 27 R606 R607 608 R...

Page 48: ...5 COtlIp 44655 COtlIp 44655 COmp 44655 COtlIp 44655 MtF 44655 MtF 44655 TRANSISTORS CEA RC07 KC07 CEA RSS 301K 27 R76 47 27 R76 100K 27 R88 158 27 CF 24 77PR200 CEA RC07 RC07 R88 158 27 RP64 200 27 R8...

Page 49: ...P IC 7 24 MC724P IC 5 24 MC789P IC 7 24 MC792P IC 10 24 MC789P IC 5 24 MC789P IC 5 24 MC79OP X 8 24 MC789P IC 7 24 circuit msig 0701 Q701 Descripeian Diode Silicon Transistor Silicon Mfr Mfr Keithley...

Page 50: ...LJ 30 17554 TSDl 20 125 C179 1 2 UF 30 c904 1 2 IF 2ov ETT 17554 TSDl 20 125 c905 1 2 p 20 ETT 17554 TSDl 20 125 I c179 1 2 I F C179 1 2 p F 30 30 C906 1 2 p 2ov ETT 17554 TSDl 20 125 c179 1 2 iJE 30...

Page 51: ...Camp Camp CLXtlp COmp 44655 RC07 R76 820 30 44655 RC07 R76 820 30 44655 RC07 R76 820 30 44655 RC07 R76 820 30 44655 RC07 R76 820 30 44655 RC07 R76 820 30 44655 RC07 R76 560 30 44655 RC07 R76 1K 30 446...

Page 52: ...EGRATED CIRCUITS Mfr Part No ED 001 ED 0033 ED 001 C280AEIPlOOK ED 100 ED 100 ED 470 ED 470 502 10 226 TSDZ 20 106 Keiehley Fig Part NO Ref CZZ OOlM 22 CZZ 0033M 22 C22 oom 22 C178 O lW 22 c22 1OOP 22...

Page 53: ...07 07263 2133565 TG 39 QllO8 07263 2N3565 TG 39 Q1109 07263 2N3565 TG 39 QlllO 07263 2N3565 TG 39 22 22 22 22 22 22 22 22 22 NOTE on schematic diagram 234813 there are 6 buffers labeled A through F Ea...

Page 54: ...cover8 m tsf be removed for this adjustment 1 Set LINE Switch to 117V or 234V if higher line voltage is only availeble Switch 5101 2 connect voltage of 115v c3 volts or 234V t6 volts 60 Hz or 50 Hz s...

Page 55: ...shields and top bottom co ara are installed With power on allow the Model 445 to stabilize in the calibration area for two houre e Picoammeter Ranxe Calibration IMPORTANT Ihe range calibration must s...

Page 56: ...8 Verify 0 fO lmV Verify 1 05v O lmV Adjust lo CAL Rl234 1 05v 0 3 Verify 0 105V t 0 6 Verify o l05V 0 6 Verifv 0 0 1mv Verify 1 05v O lmV Adjust 1O 7 CAL R1232 c1 05v 0 2 Verify 0 105v f 0 5 Verify o...

Page 57: ...es with 0 6 Apply a minus input curre t to Model 445 7 Adjust Current Source and front panel zero as eces88ry far ANALOG OUTPUT reading of 2 0995V o lmv 12 With RESET edjuated on oseilloac pe grid lin...

Page 58: ...MODEL 445 CALIBRATION NTEGRATE DISCHAR I _ 0 REFERENCE I I I I I 0 INTEGRATOR ZERO ZERO OSCILLOSCOPE SETTINGS VERT lmV DIV HORIZ 5MS DIV SYNC EXT TRIG FIGURE33 A D Converrer Zero Adjustments 0774 55...

Page 59: ...hkosh Nebr 69154 components Inc Smith Street Biddeford Maine 04005 General Radio Co 22 Baker Avenue West Concord Mess 01781 Hethavey Inetru nts Inc 5800 E JewalL Avenue Denver Colorado 80222 Ohmite ME...

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Page 72: ...a Notie the calibration for details see reverse side of this form 3 To help repair the instrument briefly describe the problem 4 1s the problem Constant 1ntermittant Under what conditions does the pr...

Page 73: ...ollowing categories 1 Report of Calibration Certified Traceable to the National Bureau of Standards 2 Calibration Report 3 Certificate of Compliance 4 Recalibration All calibration and certification p...

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