Marconi_TF-1313A 电路图.pdf

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1、MANUAL INSTRUCTION RadioFans.CN 收音机爱 好者资料库 NOTES AND CAUTIONS ELECTRICAL SAFETY PRECAUTIONS This equipment is protected in accordance with IEC Safety Class 1. It has been designed and tested according to IEC Publication 348, Safety Requirements for Electronic Measuring Apparatus, and has been suppli

2、ed in a safe condition. The following pre- cautions must be observed by the user to ensure safe operation and to retain the equip- ment in a safe condition. Defects and abnormal stresses Whenever it is likely that protection has been impaired, for example as a result of damage caused by severe condi

3、tions of transport or storage, the equipment shall be made inoperative and be secured against any unintended operation. Removal of covers Removal of the covers is likely to expose live parts although reasonable precautions have been taken in the design of the equipment to shield such parts. The equi

4、pment shall be disconnected from the supply before carrying out any adjustment, replacement or maintenance and repair during which the equipment shall be opened. If any adjustment, maintenance or repair under voltage is inevitable it shall only be carried out by a skilled person who is aware of the

5、hazard involved. Note that capacitors inside the equipment may still be charged when the equipment has been disconnected from the supply. Before carrying out any work inside the equip- ment, capacitors connected to high voltage points should be discharged; to discharge mains filter capacitors, if fi

6、tted, short together the L (live) and N (neutral) pins of the mains plug. Mains plug The mains plug shall only be inserted in a socket outlet provided with a protective earth contacts The protective action shall not be negated by the use of an extension lead without protective conductor. Any interru

7、ption of the protective conductor inside or outside the equipment is likely to make the equipment dangerous. Fuses Note that there is a supply fuse in both the live and neutral wires of the supply lead. If only one of these fuses should rupture, certain parts of the equipment could remain at supply

8、potential. To provide protection against breakdown of the supply lead, its connectors, and filter where fitted, an external supply fuse (e.g. fitted in the connecting plug) should be used in the live lead. The fuse should have a continuous rating not exceeding 6 A. Make sure that only fuses with the

9、 required rated current and of the specified type are used for replacement. The use of mended fuses and the short-circuiting of fuse holders shall be avoided. RADIO FREQUENCY INTERFERENCE This equipment conforms with the requirements of lEC Directive 76/889 as to limits of r.f. interference. (2a) Ra

10、dioFans.CN 收音机爱 好者资料库 Contents Section 1 GENERAL INFORMATION 1.1 1.2 1.3 Section 2 OPERATION 2. 2. 2. 2. 2. 2. 2. 2.8 2.9 2.10 2.11 ,1 ,2 .3 .4 5 ,6 .7 Introduction Data summary Accessories Installation Controls and connectors Preliminaries Connecting the component Resistance measurement Inductance

11、measurement Notes on inductlve loss balancing Using the D. C. Choke Adaptor Type TM Capacitance measurement Notes on capacitive loss balancing Use of external oscillator and detector 6113 9 10 10 12 16 17 18 21 21 Section 3 TECHNICAL DESCRIPTION 3.1 Circuit summary 3.2 Measuring bridge a. c. supply

12、3.3 Measuring bridge d. c. supply 3.4 Measuring bridge circuits 3.5 Amplifier detector 3.6 Power supplies 3.7 D. C. Choke Adaptor Type TM 6113 23 24 24 24 25 26 26 Section 4 MAINTENANCE 4.1 General 4. 2 Removal from case 4.3 Access to components 4.4 Mains input adjustments 4.5 Working voltages 4.6 R

13、eplacement of valves 4. 7 Adjustment of preset components 4.8 Checking the loss balance diai calibration 4. 9 Access and adjustment to balance control assembly 28 28 28 28 28 31 31 36 36 Section 5 REPLACEABLE PARTS Universal bridge D. C. choke adaptor 41 53 Section 6 CIRCUIT DIAGRAMS Fig. 6.1 Power

14、supply and oscillator Fig. 6.2 Bridge Fig. 6.3 Detector Fig. 6.4 D. C. choke adaptor 47 49 51 53 1313A (1) RadioFans.CN 收音机爱 好者资料库 General information 1.1 INTRODUCTION TF 1313A is a general-purpose impedance bridge with one tenth per cent measurement accuracy over a wide range of inductance, capac-

15、itance, and resistance values. It offers except- ional discrimination and resettability, wide-range loss balancing, and facilities for using an external oscillator and detector. The single direct-reading dial used for L, C, and R measurements has coarse aiid fine con- centric controls; the coarse on

16、e moves in 1% steps and the fine gives continuously variable interpolation between steps. The variable and non-linear sensitivity of the detector facilitates easy measurement of completely unknown comp- onents. An external audio oscillator can be plugged in where L and C measurements are req- uired

17、at frequencies other than the internal 1 and 10kc/s; the detector output is available externally to allow an oscilloscope or headphones to be used for balance indication. This bridge can be used for precision eval- uation of resistance, capacitance and inductance, for measuring the dissipation facto

18、r of capacitors and Q of inductors, and for quickly identifying unknown components. Measurements on high-loss components are made easier by the low D and Q ranges of the loss balance control and the relative independence between the adjustment of the main and loss balance controls. Its high discrimi

19、nation and resettability make it particularly suitable for comparative measurements such as checking the difference between an unknown and a standard component. Measurements on inductors carrying d. c. can be made by using Adaptor TypeTM6113, which is available as an optional accessory, while an ext

20、ernal d. c. supply can be connected direct for polarizing capacitors. Fig. 1.1 0-1% Universal bridge TF 1313A 1313A (la) 1.2 DATA SUMMARY Resistance measurement General information Range Accuracy : Residual resistance 3 m to 110 M. in eight ranges with maxima of 11, 110, 1.1 k, 11 k, 110 k, 1.1 M, 1

21、1 M, 110 M. Basic measurement error : 0.1% of reading, or 0. 015% of rang maximum, whichever is greater. Rang errors : 110 to 1.1 M ranges inclusive - basic errors only. 11 and 11 M ranges - basic errors, and additional 0.1% of reading. 11 M X 10 rang - basic errors, and additional0.15% of reading.

22、Less than 0.003 . Inductance measurement Rang : Accuracy : 0.1 H to 110 H in seven ranges, with maxima of 110 H, 1.1 mH, 11 mH, 110 mH, 1.1 H, 11 H, 110 H. Basic measurement error at 1 kc/s : 0.1% of reading, or 0. 015% of rang maximum whichever is greater. Basic measurement error at 10 kc/s : 0. 2%

23、 of reading, or 0. 025% of range maximum, whichever is greater. Residual inductance : Range errors : 1.1 mH to 11 H ranges inclusive - basic errors only. 110 H and 110 H ranges - basic errors, and additional 0.1% of reading. Additional errors at Low Q : (0.1 xf/Q)%, where f is in kc/s. Typically 0.

24、05 H. Capacitance measurement Range : Accuracy : (when D is not greater than 0.031) 0.1 pF to 110 F in seven ranges, with maxima of 110 pF, 1100 pF, 0.011 F, 0.11 F, 1.1 F, 11 F, 110 F. Basic measurement error at 1 kc/s : 0.1% of reading, or 0. 015% of range maximum, whichever is greater. (When D is

25、 greater than 0. 031 additional error is typically 0 . 3 D 2 % ) . 1313A (lc) General information Accuracy : (when D is not greater than 0.031) - continued - Basic measurement error at 10 kc/s : 0. 2% of reading, or 0. 025% of range maximum, whichever is greater. (When D is greater than 0.031 and le

26、ss than 0. 31, additional error is typically 6D 2%.) Range errors ; 1100 pF to 11 F ranges inclusive - basic errors only. 110 pF and 110 F ranges - basic errors, and additional 0.1% of reading. Residual capacitance Less than 0. 05 pF. Temperature range Temperature coefficient 18 C to 28 C for the st

27、ated accuracies. Additional error of 0.01% per degree C, for temperatures between 10C and 18C, and 28C and 35C. Q and D measurement Range : Accuracy : Low Q range : Normal Q range Normal D range High D range : 1 kc/s 0 to 3 0.5 to 31 0.0005 to 0.031 0,005 to 3 10 kc/s 0 to 30 5 to 310 0.005 to 0.031

28、 (limited) Not required Normal Q : 5% of reading, 0. 5% of full scale. Normal D : 5% of reading. Low Q and High D : 10% of reading, 3% of full scale. Additional D or 1/Q error at 1 kc/s and below : less than 0. 0005 with correction supplied (on top of instrument), or less than 0. 0015 without correc

29、tion. (Above 1 kc/s multiply by f kc/s.) Bridge sources and detector Internal sources : External oscillators : 1 kc/s and 10 kc/s oscillators for L and C measurement, accuracy 2. 5%; output level, depending on loading, up to 750 mV. D. C. supply for R measurement; less than, 100 mW component loading

30、. Frequency range: 20 c/s to 30 kc/s. Input level required : 3 to 20 V depending on frequency. (An external tuned detector is also necessary to achieve the quoted measurement accuracies.) Additional L and C errors Typically : Frequency 20 c/s 100 c/s 20 kc/s 30 kc/s % error .05 .03 0.2 0.35 1313A (l

31、b) Test terminal voltage at balance: General information CAPACITOR BIAS : POWER SUPPLY A. C. mains : DIMENSIONS enables d. c. currents up to 200 mA from an external supply to be passed through inductors under test at 1 kc/s in the range 100 mH to 100 H; fitted with test leads for attaching to bridge

32、 terminals. Errors introduced by the adaptor do not generally exceed 3% and may be eliminated by simple substitution methods. Up to 350 V d. c. may be applied for polarizing electrolytic capacitors. 100 to 130 V and 200 to 250 V, 45 to 180, 275 to 300, 366 to 400 c/s. 25 VA. Operation 2.1 INSTALLATI

33、ON The 0.1% Universal Bridge is normally dis- patched with its valves in position and with its mains input circuit adjusted ready for immediate use on 240 V within the basic supply frequency range 45 to 400 c/s. Note that harmonics of supply frequencies of 200, 250 and 333 c/s may give rise to inter

34、ference which will obscure the balance point. If required, the instrument may be adjusted for operation from other supplies wlthin the ran- ges 100 to 130 and 200 to 250 V. To check, or alter the tappings on the mains transformer, refer to Section 4.4. 2.2 CONTROLS AND CONNECTIONS (T) TEST TERMINALS

35、. Connect the component between the Hl and DET terminals. (2) COMPONENT PLATFORM and ABRIDGED OPERATING INSTRUCTIONS. Supports components, isolating them from chassis. Fig. 2.1 Controls and connectors 1313A (1) Operation L C R switch. surement. Adjust for appropriate mea- RANGE switch. Adjust to sui

36、t component. If approximate value unknown, set BALANCE controls to half scale, and then select range giving lowest meter reading. BALANCE METER. minimum reading. Adjust controls for SENSITIVITY control. Adjust initially to give half scale meter reading. As balance is approached increase sensitivity

37、to give required discrimination. COARSE BALANCE control. Set to half scale while searching for correct range, and then adjust for minimum meter reading. FINE BALANCE control. . Adjust for minimum meter reading once minimum for COARSE BALANCE control has been foimd. Note that when the instrument has

38、been idle for some time the protective oil film may, before dispersion, cause erratic balance, A number of brisk rotations will restore the contact surface. LOSS BALANCE control. Adjust to obtain final balance, (minimum meter reading) in conjunction with FINE BALANCE control. EXT D-Q terminals. Link

39、ed for measure- ments at 1 kc/s to 10 kc/s; connect to ext- ernal potentiometer, to give continuous coverage when using an external oscillator at frequencies below 1 kc/s. BIAS jack. Connect external d. c. supply of up to 350 V for polarizing capacitors. SUPPLY switch. PILOT LAMP. 2.3 PRELIMINARIES

40、Having checked that the instrument is adjusted for the supply voltage it will use, proceed as fol- lows :- 1. If necessary, mechanically zero the meter. 2. Connect the mains lead to the power supply. 3. Set the SUPPLY switch to ON; the pilot light should now glow. 4. Before using the instrument, all

41、ow a short warm-up period. Two or three minutes is normally sufficient for most purposes. FINE D-Q control. Adjust for final balance only when LOSS BALANCE control is too coarse. 1 kc/s - 10 kc/s switch. Select 1 kc/s except for low value inductors. LOSS BAL- ANCE dial readings multiplied by 10 when

42、 this switch is at 10 kc/s. Inopera.tive for resistance measurements. D-Q switch. Select range appropriate to component under test. Inoperative for res- istance measurements. EXT OSC. Connect an external oscillator with frequencies from 20 c/s to 35 kc/s. EXT DET socket. Connect an external detector

43、 to monitor output, when using an external oscillator. If you are using this Bridge for the first time, it will be helpful at this stage to get to know the recommended technique of reading the main dial, before making a measurement. The coarse control moves the pointer of the outer dial in steps equ

44、al to one dial division; the fine control for the inner dial is continuously variable, and the range 0 to 100 of the inner scale is equivalent to one division of the outer scale. The coarse control is a switch with light indexing for ease of operation; no attempt should be made to obtain a setting b

45、etween the marks. The value of a component is most easily found by first noting the reading of the outer scale followed by the reading of the inner scale, and then putting in the decimal point by referring to the fig- ure displayed in the nearest scale window. Typical examples are shown in Fig. 2.2.

46、 1313A (la) operation 2.4 CONNECTING THE COMPONENT Connect the component between the HI and DET terminals, using short leads where possible. Small components can often be directly supported by the test terminals; those which cant be sup- ported should be laid on the insulated component platform. Not

47、e the following precautions : - (a) Impedance between the HI side of the comp- onent and earth, shunts the balance arm of the bridge, and may result in an inaccurate reading. (b) Stray pick-up on the lead to the DET terminal is applied to the input of the bridge detector and may cause difficulty in

48、obtaining a clear balance indication. Using a screened lead, with the screen connected to the E terminal, helps to avoid this effect. (c) The presence of an earth on either side of the component will short-circuit the bridge and make measurement impossible. (d) The bridge energizing voltages appeari

49、ng at the test terminals (see Data Summary) are too small to cause damage to the component or shock to the operator. (e) When measuring screened inductors, the screen may be left disconnected, or connected to the E terminal. 2.5 RESISTANCE MEASUREMENT Resistance can be measured at d. c. only. The 1 kc/s-10 kc/s switch and the loss balance controls are inoperative. Fig. 2.2 L: Reading 3,782 mH C: Reading 0.006652F R: Reading 8