Kenwood VT-181_VT-181E 电路图.pdf

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1、AC VOLTMETER VT-181/VT-181E SERVICE MANUAL KENWOOD TMI CORPORATION 1998-4/B51-1132-00 (K/K) HANDLE: (K01-0564-08) HANDLE COVER : (B09-0410-08) FRONT PANEL VT-181: (A63-0301-08) VT-181E : (A63-0316-08) SIDE FRAME (A13-2254-08) PUSH KNOB (K24-3015-08) KNOB (K21-0959-08) RORARY KNOB (K21-0961-08) RUBBE

2、R FOOT (J02-0543-08) VT-181/VT-181E(K) INT 98.4.9 10:26 AM yW 2 RadioFans.CN 收音机爱 好者资料库 VT-181/VT-181E 2 The following instructions are for use by qualified personnel only. To avoid electric shock, do not perform any servicing other than contained in the operating instructions unless you are qualifi

3、ed to do so. WARNING CONTENTS SPECIFICATIONS .3 SAFETY .4 CIRCUIT DESCRIPTION.5 BLOCK DIAGRAM .6 ADJUSTMENT.7 PARTS LIST.9 PARTS LIST (ELECTRICAL).10 SCHEMATIC DIAGRAM .15 P.C. BOARD .21 VT-181/VT-181E(K) INT 98.4.9 10:26 AM yW 3 RadioFans.CN 收音机爱 好者资料库 VT-181/VT-181E 3 SPECIFICATIONS Measurable Vol

4、tage dB dBm Error Frequency response Input impedance Durable input voltage Gain Output voltage Output resistance Frequency response Distortion Signal to noise ratio 1mV to 300mV in 12 ranges:1,3, 10,30,100,300mV,1,3,10,30, 100,300V full scale. -80 to +50dB(0dB=1V) -80 to +52dBm(0dBm=1mW at 600) 500V

5、 (DC +AC peak) 1V to 300V range 100V (DC +AC peak) 1mV to 300mV range Within specifications temp./ hum.range Full operation temp./ hum.range Line voltage Power consumption Dimensions WXHXD(mm) Net Weight Accessories Power cable Input cable Replacement fuse Instruction manual Adjust driver Less than

6、1% at full scale (Rated by signal-noise ratio in 1mV and 1V range) Over 40dB at full scale Within 3% of full scale at 1kHz 0.3mV to 100mV in 12 ranges:0.3, 1,3,10,30,100,300mV,1,3,10, 30,100V full scale. -90 to +40dB(0dB=1V) -90 to +42dBm(0dBm=1mW at 600) 500V (DC +AC peak) 1V to 300mV range 100V (D

7、C +AC peak) 0.3mV to 300mV range Less than 1% at full scale (Rated by signal- noise ratio in 0.3mV,1mV and 1V ranges) Over 30dB at 0.3mV range Power Supply Section Meter Section VT-181EVT-181Item Environmental Indoor Use Only Altitude up to 2000m OVERVOLTAGE CATEGORYPOLLUTION DEGREE2 Amplifier Secti

8、on 10% at 5Hz to 1Mhz, 5% at 10Hz to 500kHz and 2% at 20Hz to 100kHz as reference to 1kHz response. 10M 5%, with less than 50pF parallel capacitance. 60dB 1dB(Approx.70dB) 1Vrms 20% 60020% at 1kHz Within3dB at 5Hz to 500kHz 10 to 40C / 80% RH or less 0 to 50C / 80% RH or less 100/120/220/230/ Vac 10

9、% 50/60Hz Max.6.9W 128(128)X190(210)X239(259) Value in ( ) include protrusions 2.8kg 1pc CA-41p 1pc 1pc 1copy 1pc Stability Residual voltageLess than 20uV with input shorted on 1mV range Less than 30uV with input shorted on 0.3mV range Within 0.5% of full scale for 10 line voltage fluctuation VT-181

10、/VT-181E(K) INT 98.4.9 10:31 AM yW 6 RadioFans.CN 收音机爱 好者资料库 VT-181/VT-181E 4 SAFETY Before connecting the instrument to a power source, care- fully read the following information, then verify that the proper power cord is used and the proper line fuse is installed for power source. The specified vo

11、ltage is shown on the rear panel. If the power cord is not applied for specified voltage, there is always a certain amount of dan- ger from electric shock. Line voltage This instrument operates using ac-power input voltages that 100/120/220/230 V at frequencies from 50 Hz to 60Hz. Power cord The gro

12、und wire of the 3-wire ac power plug places the chassis and housing of the instrument at earth ground. Do not attempt to defeat the ground wire connection or float the instrument ; to do so may pose a great safety hazard. The appropriate power cord is supplied by an option that is specified when the

13、 instrument is ordered. The optional power cords are shown as follows in Fig.1 Line fuse The fuse holder is located on the rear panel and contains the line fuse. Verify that the proper fuse is installed by replacing the line fuse. Voltage conversion This instrument may be operated from either a 100

14、to 230V, 50/60Hz power source. Use the following procedure to change from 100 to 230V operation or vice verse. 1. Remove the fuse holder. 2. Replace fuse F1 with a fuse of appropriate value. 3. Reinsert it for appropriate voltage range. 4. When performing the reinsertion of fuse holder for the volta

15、ge conversion, the appropriate power cord should be used. (See fig.1) SAFETY North American 120 volt/60 Hz Rated 15 amp (12 amp max ; NEC) Universal Europe 230 volt/50 Hz Rated 16 amp U.K. 230 volt/50 Hz Rated 5 amp Australian 240 volt/50 Hz Rated 10 amp North American 240 volt/60 Hz Rated 15 amp (1

16、2 amp max ; NEC) Switzerland 230 volt/50Hz Rated 10 amp Fig.1 Power Input Voltage Configuration Plug configurationpower cord and plug type Factory installed instrument fuse 0.2A, 250V slow blow 5x20mm 0.1A, 250V slow blow 5x20 mm 0.1A, 250V slow blow 5x20 mm 0.1A, 250V slow blow 5x20 mm 0.2A, 250V s

17、low blow 5x20mm 0.3A, 250V slow blow 5x20 mm Line cord plug fuse None None None Parts No. for power cord E30-1982-08 E30-1985-08 E30-1986-08 None 5A Type C None E30-1983-08 VT-181/VT-181E(K) INT 98.4.9 10:31 AM yW 7 VT-181/VT-181E 5 General A Signal voltage to be measured, which is input from the IN

18、PUT connector, is passed through the First Attenuator and is converted to a low impedance by the Impedance Convertor. The impedance-converted signal is normalized, or further attenuated in proportion to 1mVrms fullscale value through the Second and Third Attenuator. The normalized signal is magnifie

19、d 20-fold by the Main Amplifier and is fed to the Output Amplifier and the Absolute-Mean Value Detec- tor. The Output Amplifier magnifies the signal 50-fold and feeds to the OUTPUT connector. The Absolute-Mean Value Detector converts the signal from the Main Amplifier to DC current in proportion to

20、the absolute mean value. The con- verted signal activates the Meter. The Attenuator Control encodes the signal led from the RANGE selector to generate an Attenuator Control signal. This signal controls the First, Second and Third attenuator to set the sensitivity corresponding to each range. The Pow

21、er Supply feeds to the functional circuit 5V DC voltages stabilized by its IC regulator. Description of Functional Circuit 1) First Attenuator A potential divider act as a attenuator. The amount of atten- uation is switched in tow steps by relay contacts:0dB and - 60dB. 2) Impedance Converter A FET

22、differential input Amplifier act as a impedance con- verter with 0dB(10dB) gain. Which converts the First Attenu- ator output signal to a sufficiently low impedance and feeds of the Second Attenuator. 3) Second Attenuator A resistance divider act as a attenuator. The amount of attenuation is switch

23、in two steps by relay contacts:0dB and -30dB. 4) Third Attenuator A resistance divider network act as a attenuator. The amount of attenuation is switched in four steps by FET switch:0dB,-10dB,-20dB,and -30dB. 5) Main Amplifier A wideband,non-inverting differential amplifier act as the main amplifier

24、. Which has high input impedance,low output impedance and 20-fold gain. This output signal level is 20mVrms for the fullscale read on the Meter. 6) Output Amplifier A wideband,non-inverting differential amplifier act as a out- put amplifier. Which has 50-fold gain and 600 output impedance. The outpu

25、t signal level is 1Vrms for fullscale read on the Meter,and works stable even for capacitive loads. 7) Absolute-Mean Value Detector An absolute-mean value detector comprised of a high through-rate and high gain amplifier. Which has a very good linearity by negative feedback from the current flowing

26、through the Meter load. In switching, this provides a suffi- ciently wide frequency band so that the high frequency phase compensation circuit is reset. 8) Attenuator Control A logic control circuit comprised of a diode matrix and output buffer transistors. This encodes a 12-bit signal from the RANG

27、E selector switch to 6-bit signals,which control the First,Second and Third Attenuator. The remote control con- nector is connected to this circuit. 9) Rotary Switch A 12 contacts rotary switch which design the operation range. For different range,different attenuation ratio are acti- vated. 10) Gai

28、n Control To using the dB scale to measure relative voltage, you may get a reference reading by change the gain control. (relative ref.) Which capable to vary 0 to 10dB. 11) Power Supply The power source circuit supply5V DC from the AC input. Which contain a silicon diode bridge for full-wave rectif

29、ica- tion,high-capacitance electrolytic capacitors for smoothing,and an IC regulator stabilization. CIRCUIT DESCRIPTION The voltage or sentence in parenthes is applicable in case of the VT-181E. In studying the operation of each circuit in voltmeter please refer to BLOCK DIAGRAM. VT-181/VT-181E(K) I

30、NT 98.4.9 10:31 AM yW 10 VT-181/VT-181E 6 BLOCK DIAGRAM CH1. PC BOARDOUTPUT-1 INPUT RELATIVE REF METER DC5V GND DC-5V POWER ON/OFF IMPEDANCE CONVERTER MAIN AMPOUTPUT AMP ABSOLUTE MEAN VALUE DET AC 100V/120V/220V/230V 50/60Hz 1st ATT2nd ATT3rd ATT GAIN CONTROL ATT CONTROL ROTARY SW POWER TRANSFORMER

31、POWER SUPPLY VT-181/VT-181E(K) INT 98.4.9 10:31 AM yW 11 300mV rangeVR102 (Unless otherwise specified, the above connection should be used as to the follow- ing items.) RANGE: 300 mV 1) Input a 1 kHz (or 400 Hz), 300 mVrms sine wave, and set the pointer to 3.0 of the 0-3 scale. Check that the variab

32、le range is less than 98% and more than 102% with respect to 3.0 (full-scale). 2) Waveforms shown on the oscilloscope shall not be deformed. ITEMPROCEDUREADJUSTMENT POINT Oscilloscope 50 oscillator Main unit CAL OUT IN Oscillator or calibrator OscillatorCalibrator OKNGNG OUTOUT VT-181/VT-181E 7 ADJU

33、STMENT To obtain the best performance, periodically calibrate the unit. Sometimes, only one mode need be calibrated, while at other times, all modes should be calibrated. When one mode is calibrated, it must be noted that the other modes may be affected. When calibrating all modes, perform the calib

34、ration in the specified sequence. The following calibration required an accurate measuring instrument and an insulated adjusting flat blade screwdriver. If they are not available, contact your dealer. For optimum adjustment, turn the power on and warm up the scope suffi- ciently (more than 30 minute

35、s) before starting. Before calibrating the unit, check the power supply voltage. TEST EQUIPMENT REQUIRED The following instrument or their equivalent should be used for making adjustment. PREPARATION FOR ADJUSTMENT Control Settings The control settings listed below must be used for each adjustment p

36、rocedure. Exceptions to these settings will be noted as they occur. After completing a adjustment, return the controls to the fol- lowing settings. Test Equipment Digital Multimeter Frequency Counter Oscilloscope Model DL-712 FC-756 CS-6010 Maker KENWOOD KENWOOD KENWOOD NAME OF KNOBS RANGE RELATIVE

37、REF POSITION VT-181 : 300V VT-181E : 100V CAL Test Equipment Calibrator CR Oscillator Attenuator Q-Meter Distortion Meter Insulation Meter 50 Termination Model 5100B AG-203 RA-920 4343B 885 SM-5 TA-57 Maker FLUKE KENWOOD KENWOOD YHP Shibasoku TOA KENWOOD VT-181/VT-181E(K) INT 98.4.9 11:46 AM yW 14 1

38、V rangeVR101 RANGE: 1V 1) Input 1kHz (or 400 Hz), 1 Vrms sine wave, and set the pointer to 10.0 V of the 0- 10 scale. Check that the variable range is less than 98% and more than 102% with respect to 10.0 (full-scale). 2) Waveforms shown on the oscilloscope shall not be deformed. VT-181/VT-181E 8 AD

39、JUSTMENT ITEM 100 kHz TC101 frequency RANGE: 1V characteristics 1) Input a 1kHz (or 400 Hz), 1 Vrms sine wave, and adjust the oscillator output so that the pointer of the set points at 9.0. 2) Adjust the TC so that the pointer points at 9.0 when the frequency is changed to 100 kHz while the oscillat

40、or output remains unchanged. PROCEDUREADJUSTMENT POINT 0 3 10 Scale 9 Scale 0-10 Scale 0-3 VT-181/VT-181E(K) INT 98.4.9 10:31 AM yW 15 VT-181/VT-181E 9 PARTS LIST * New Parts Parts without Parts No. are not supplied. Les articles non mentionnes dans le Parts No. ne sont pas fournis. Teile ohne Parts

41、 No. werden nicht geliefert. Ref. No Add- ress DescriptionParts No. L : ScandinaviaK : USAP : CanadaR : Mexico Y : PX(Far East, Hawaii)T : EuropeE : EuropeG : Germany Y : AAFES(Europe)X : AustraliaM : Other Areas indicates safety critical components. A01-4087-08CASE;TOP A01-4088-08CASE;BOTTOM A13-22

42、54-08FRAME A22-1344-08SUB PANEL A63-0301-08PANEL A83-0150-08REAR PANEL B09-0410-08CAP B31-0778-08METER B42-6147-08LABEL;KENWOOD B42-6146-08S/NO.LABEL B63-0304-08INSTRUCTION MANUAL; JAP./ENG./CHIN E04-0503-08BNC RECEPTACLE E04-0504-08BNC RECEPTACLE E23-1533-08EARTH LUG E30-1984-08JIS POWER CORD E30-1

43、982-08CEE POWER CORD E30-1986-08SAA POWER CORD E30-1983-08UL/CSA POWER CORD E30-1985-08BS POWER CORD E68-0626-08AC INLET F50-0129-08FUSE(5*20) F50-0130-08FUSE(5*20) F15-0785-08BLIND PLATE F11-1528-08SHIELD CASE J02-0543-08RUBBER FOOT J21-8927-08BRACKET J11-0513-08CLAMPER K01-0564-08HANDLE K21-0959-0

44、8KNOB K21-0961-08KNOB L07-1552-08POWER TRANSFORMER R31-0810-05V.R. N09-4530-08SCREW,SEMS BINDING M3.5X12 N09-4531-08SCREW,TRUSS TAPTITE M3x6 N09-4532-08SCREW,FLAT HD M4X15 N10-2030-41HEXAGON NUT M3 N10-2040-41HEXAGON NUT M4 N14-0644-08FLANGE NUT M3.5 N15-1030-41PLAIN WASHER N19-0755-08WASHER N19-075

45、4-08WASHER N16-0030-41WASHER N16-0040-41SPRING WASHER N30-2606-41SCREW,PAN HD M2.6X6 N30-3012-41SCREW,PAN HD M3X12 N30-3006-41SCREW,PAN HD M3X6 N16-0030-41SPRING WASHER N32-2606-41SCREW,FLAT HD M 2.6X6 N32-3006-41SCREW,FLAT HD M3X6 N66-3008-41SCREW,SEMS PAN HD M3X8 H53-0232-08CARTON BOX H10-2894-08F

46、OAMED STYREN PAD H20-1750-08VINYL COVER W02-2355-08MAIN UNIT W02-2368-08PANEL UNIT W02-2365-08RANGE UNIT W01-0522-08ACCESSORIES 1 * New Parts Parts without Parts No. are not supplied. Les articles non mentionnes dans le Parts No. ne sont pas fournis. Teile ohne Parts No. werden nicht geliefert. Ref. No Add- ress DescriptionParts No. L : ScandinaviaK : USAP : CanadaR : Mexico Y : PX(Far East, Hawaii)T : EuropeE : EuropeG : Germany Y : AAFES(Europe)X : AustraliaM : Other Areas indicates safety critical components. A01-4087-08CASE;T