KEI 247 INST 电路图.pdf

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1、Model 247 High Voltage Supply Instruction Manual Contains Operating and Servicing Information RadioFans.CN 收音机爱 好者资料库 WARRANTY Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year from date of shipment. Keithley Instruments, Inc.

2、 warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable batteries, diskettes, and documentation. During the warranty period, we will, at our option, either repair or replace any product that proves to be defective. To exercise this warranty, write or call yo

3、ur local Keithley representative, or contact Keithley headquarters in Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid. Repa

4、ired or replaced products are warranted for the balance of the origi- nal warranty period, or at least 90 days. LIMITATION OF WARRANTY This warranty does not apply to defects resulting from product modification without Keithleys express written consent, or misuse of any product or part. This warrant

5、y also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions. THIS WARRANTY IS IN LIEU OF ALL OTHER WARRAN TIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FIT

6、NESS FOR A PARTICULAR USE. THE REMEDIES PROVIDED HEREIN ARE BUYERS SOLE AND EXCLUSIVE REMEDIES. NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, INDI- RECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS INSTRUMENTS AND SOFTWARE

7、EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY. Test Instrumentation Grou

8、p, Keithley Instruments, Inc. ? 28775 Aurora Road ? Cleveland, Ohio 44139 ? (216) 248-0400 * Fax: (216) 248-6168 CHINA: Keithley Instruments, Inc. * Holiday Inn Lido ? Office Building 4 fo.OZ% of setting/b hrs., at constant temperature after r+hour warm-up. TEMPEIUTURE COEFFICIENT (W-18C lmV,3mVp-pl

9、kV,lmA, lOHz-1OOkHz SEITLING TIME: 4 seconds to within 1V with full resistive load. OVERLOAD PROTECTIONr Short circuit proof, arc protected, self restoring. METER Monitors voltage output. ENVIRONMENT: Operating: 0 to 50C, 0 to 80% relative humidity up to 35C Storage: -40 to 75C CONNECTORz Rear panel

10、, MI-IV Type LJG931/U. POWER: 90-125V/180-25OV, 50-6OHz,13OVA. DIMENSIONS,WEIG:483mmwidex89mmhighx273deep(l9inx3/in.x103/4 in.), excluding handles. Four holes spaced for rack mounting. Net weight 5.9kg (13 Ibs.). ACCESSORIES SUPPLIEIX Instruction manual, UG932/U mating connector, mounting feet for b

11、ench operation. Specifications subject to change without notice. Table of Contents SECTION 1 - General Information 1.1 PURPOSEOFEQUIPMENT . .I- 1 1.2 DESCRIPTION . l-l 1.3 SPECIFICATIONS . l-l 1.4 sAFETYsYMEioLsANDTERMs. . l- 1 1.5 WINFoRMATION.l- 2 SECTION 2 - Operation 2.1 INSTALLATION . 2-l 2.2 F

12、RONTl?ANELCONTROLSANDTERMlNALS . .2- 1 2.3 REAR PANEL CONNECTORS AND TERMINALS . 2-2 2.4 l?REPAlK!JONFORUSE . .2- 3 2.5 INPUTPOWER . 2-3 2.6 CURRENTLIMITING . .2- 3 27 HIGH VOLTAGE OUTPUT . 2-3 2.8 APPLICATIONS . 2-4 2.8.1 Application of 247 wit therefore, it reads the output at all times. NOTE The

13、output voltage is the sum of the Voltage dial and the Voltage switch. 2-l SECTION 2 Operation 2.3 REAR PANEL CONNECTORS AND Fuse -The line power fuse (Slo-Blo) is rated 1.6A, 250V TERMINALS for 90-127V AC operation and 0.8A, 250V for 180254V AC operation. GND -The case ground screw (GND) is to be co

14、nnected to the measurement system common. Line Voltage Selector - The line voltage selector selects the appropriate line voltage 90-127VAC or MO-254V AC. Output Connector - The output connector is a h4lW type UG931/U connector. It mates with a h4HY type UG932/U connector. Line Plug - The recessed li

15、ne plug accepts a three-wire female line plug for line power. j Figure 2-l. Model 247 Front Panel Figure 2-2. Model 247 Rear Panel 2-2 SECTTON=! Opera f ion 2.4 PREPARATION FOR USE Perform the following procedure to prepare the Model 247 .- tor use: 1. 2. 3. 4. 5. 6. 7. 8. Set the Model 247 for prop

16、er line voltage operation as specified in paragraph 2.5. Connect a ground wire from case ground (on rear panel) to the measuring system common. Set the front panel controls to: A. Power switch - OFF B. Polarity switch - OFF C. Output voltage switch - 0 D. lOtumdigitaldial- 000 (full counterclockwise

17、) Plug the line cord into the power line with a three- wire receptacle to maintain proper case ground. The line fuse ratings are as follows: Line Voltage Fuse Rating 90-127VAC 1.6A, 25OV, slow blow FU-96-7 5x2On-m 180-254VAC O.SA, 25OV, slow blow, Fu-96-6 5x2Omm WARNING 2.6 CURRENT LIMITING This uni

18、t is equipped with a three-wire grounded line cord. This must be used with a three-wire receptacle where the “third wire” is connected to earth ground, otherwise per- sonal injury or death may occur. Connect the output of the Model 247 to the circuit. Use a properly rated coaxial cable with the supp

19、lied MHV type UG932/U mating connector to insure good circuit connections and safe operation. Refer to paragraph 2.6. Set the Polarity switch to the desired polarity. Turn on the power to the instrument. With actual load and output voltage, allow one hour for warm UP- Increase the Voltage switch slo

20、wly to reach the ap- proximate desired voltage. Then trim the voltage with the Voltage dial until the desired voltage level is obtained. The Model 247 includes a current limiting circuit that automatically drops the output voltage to a safe level when the rated output current is exceeded by 20%. Ref

21、er to the Maximum Current specification when operating the unit at reduced output voltages or when operating in a current limit mode for capacitor charging. 2.7 HIGH VOLTAGE OUTPUT The high voltage output connector is located on the rear panel (output LO is connected to chassis). A MHV type UG932/U

22、shielded mating connector is supplied with each unit. Assembly insinrctions for the connector are listed below. WARNING Always turn power OFF and verify that the Model 247s output meter reads OV DC, be- fore connecting or removing any equipment. External circuits may retain High Voltage af- ter the

23、Model 247 has been turned off. Dis- charge any residual voltage before connect- ing or removing any equipment. 1. 2. 3. 4. 5. 6. Gently cut through the outer insulation without cut- ting the shield. Using a sharp point, unravel the shield braid. Clean off all traces of graphite. Cut the center insul

24、ation to the proper length cap- proximately 3/8”). Cut the center conductor to ap- protiately l/8”. Solder center conductor to male pm. Cut the braid back so it fits around the connector (see Figure 2-3). Assemble as in Figure 2-3. 2.5 INPUT POWER WARNING The AC input line voltage required to operat

25、e the instru- ment is 90-127V or 180254V. The recessed line voltage se- lector switch on the rear panel selects either 90-127V (11OV setting) or 180254V (22OV setting) operation. Keithley Part No. When the High Voltage Output is not in use, turn off the power and cover the output con- nector with th

26、e supplied cover cap. 2-3 SECTION 2 -1 )t3/32 UG-932RI Ccnn. Voltage Rating to 5kV Figwe 2-3. Connector and Cable Assembly I 2.8 APPLICATIONS The following are four examples of typical applications of theMode 247, related to the low current capabilities of electrometers and picoammeters. 2.8.1 Appli

27、cation of 247 with Photomultipliers The electron-multiplier requires up to 200 volts per stage and may have 10 to 14 stages. Thus, a totalsupply voltage up to 3OOOV may be needed. The overall sensitivity or gain is very responsive to changes in supply voltage. For this reason the long-term stability

28、 of the supply must be excellent. The specified stability of the Model 247 is valid after one-hour warm up- Warm up takes one hour with a The reference and reference con- trol and buffer provide a stable -5VDC to the front panel output voltage controls. 3-2 SECTION 4 Maintenance 4.1 INTRODUCTION Sec

29、tion 4 contains information required for the mainte- nance of Model 247 units. It is organized around the veri- fication procedure used to determine that the equipment is operating to specifications. WARNING The procedures in this section are for use only by qualified service personnel. Do not perfo

30、rm these procedures unless qualified to do so. Many of the steps in this section may expose you to potentially lethal volt- ages that could result in personal injury or Item A B r C D E P G death if normal safety precautions are not observed. WARNING To prevent a shock hazard, remove the line cord a

31、nd all test leads from the instrument before removing any cover. 4.2 RECOMMENDED TEST EQUIPMENT The recommended test equipment required to test and maintain the Model 247 is listed in Table 4-1. Table 41. Recommended Test Equipment Description Oscilloscope Digital Voltmeter Variable Auto Transformer

32、 Voltage Divider Load Resistor AC Viewing Circuit Power Line Ammeter Specifications Manufacturer Model lOMH2 Phillips 3234 -001% Keithley 192 General Radio 3030-5118 1000 to 1 Julie Research HV-10 - Clarostat VP-50-k-5Ok-50M .I% Valhalla Scientific 2000 4-l SECTION 4 Maintenance HV 0 I 4.3 PREPARATI

33、ON FOR MEASUREMENTS Connect the HIGH VOLTAGE OUTPTJT of the Model 247 to the high voltage terminal of the DC voltage di- vider (D) and to the capacitor input of the AC viewing cir- cuit (F). The low voltage terminal of the DC divider should be connected to the digital voltmeter input, and the AC vie

34、wing circuit output connected to the oscillo- scope input. Make sure that a good ground is connected to all instruments, viewing circuits and the Model 247. After the ground has been checked, adequate safety pre- cautions have been taken, and the output voltage con- trols set at zero, input power ca

35、n be applied. The AC in- put should be applied through the variable autotransfor- mer, which should be initially set for 115 or 230 volts out- put, as appropriate. 4.4 CALIBRATION ADJUSTMENTS WARNING To prevent a shock hazard, remove the power cord and all test leads from the Model 247 before removi

36、ng any cover. Remove the top cover of the Model 247. Set the Volts switch to 0. Set the Volts dial to read 1000. Adjust the Ref- erence Adjust Potentiometer (R172) of PCB 100 (see Fig- ure 4-l) for an output voltage of 1000 volts. Set the Volts dial to read 10 (with the Volts switch still at 0). Adj

37、ust the Offset Adjust Potentiometer (R171) for an output voltage of 10 volts. Set all front panel voltage con- trols for 3000 volt output and readjust the Reference Ad- just Potentiometer 01172) if necessary. Potentiometer R178 is an Overload Adjustment. To cali- brate this adjustment set the Model

38、247 for full load and full voltage (3000V at 6mA) by using the load resistor (E) on the output. Adjust R178 until the voltage drops off and then back off of R178 approximately l/8 of a turn. Potentiometer R173 is a Frequency Adjustment. To cali- brate this adjustment set the Model 247 for full load

39、and full voltage (3000V at 6mA) by using the load resistor (E) on the output. Adjust R173 for minimum AC power line current. Adjustment is not complete. The following performance tests are used to determine that the unit meets all of its specifications. 4.5 PERFORMANCE TESTS Check to assure that the

40、 procedures in paragraph 4.3 have been followed. NOTE Performance tests may be performed without doing the calibration. Turn the front panel output volts control fully clockwise until the reading on the digital voltmeter indicates maxi- mum output from the Model 247. Connect one end of the high volt

41、age load resistor to ground and the other end to a shorting stick (1 ft. insu- lated stick to which the load resistor is attached). Then, with the shorting stick, connect the load resistor across the high voltage output and observe the change in output voltage. During this no load to full load test,

42、 the digital voltmeter reading should not change by more than 0.005%. With the load connected as above, observe the AC ripple voltage on the oscilloscope. The ripple should be less than the specified peak-to-peak ripple under this condi- tion of full load and maximum output voltage. Vary the autotra

43、nsformer to produce an AC line input change of +lO% to the power supply, and again observe the change in digital voltmeter reading. This change should be less than 0.001%. 42 SECTION 4 Maintenance Additional line and load regulation and ripple measure- ments may be performed at other voltage levels

44、using the same procedure outlined above. This should not usually be necessary. Satisfactory test data at maximum output voltage and the full range of voltage control generally in- dicate that satisfactory test data will be obtained at all voltage levels. However, full range testing is performed at t

45、he factory on each unit prior to shipment. 4.6 TROUBLESHOOTING PROCEDURE A Model 247 High Voltage Power Supply consists of eas- ily replaceable plug-in printed circuit boards, and a main chassis assembly which includes the high voltage cir- cuitry. The basic troubleshooting procedure consists of det

46、ermining which of these assemblies is defective. Re- moval of the top cover provides access to the printed cir- cuit board and high voltage components. The printed cir- cuit board is secured by four screws to the bottom of the chassis. No further disassembly is required for troubleshooting purposes.

47、 Make sure all test instruments are grounded, either to the high voltage connector shield, or directly to the chassis, prior to the application of input power to the unit. The following procedures should then be followed. Remove connector/cable from I303 on PCB300 (see Fig- ure 4-l for location). This leaves only the low voltage B+ and the unregulated +20 vo