1657 RLC Digibridge 电路图.pdf

1657 RLC Digibridge Instruction Manual Foun 1657-0120-07/B1 QuadTech, Inc., 1992 5 Clock Tower Place, 210 East Maynard, Massachusetts, U.S.A. 01754 January, 1997 Tel. 978-461-2100 800-253-1230 (Sales) 800-253-1230 (Service) Fax. 978-461-4295 The material in this manual is for informational purposes only and is subject to change, without notice. QuadTech assumes no responsibility for any error or for consequential damages that may result from the misinterpretation of any procedures in this publication. Contents Instruction Manual Changes Specifications Warranty Introduction -Section 1 Installation -Section 2 Operation -Section 3 Theory -Section 4 Service and Maintenance -Section 5 Parts Lists and Diagrams -Section 6 Product will be marked with this symbol (ISO#3684) when it is necessary for the user to refer to the instruction manual in order to prevent injury or equipment damage. RadioFans.CN 收音机爱 好者资料库 These two supplementary pages contain information of improvements or modifications not documented in the current manual. All references to GenRad in the manual now apply to QuadTech, Inc. Page -Specifications (Power L and Q series or parallel; C and D series or parallel. All measurement modes are pushbutton selectable. Displays: LED-type numerical display with automatically positioned decimal points and illumination of units. For R LC, five digits (99999) and simultaneously for DQ, four digits (9999). Measurement Speed: Greater than 3 measurements per second. / Test frequencies: Pushbutton selection between 2. Accuracy re panel legends: +2%, -.01%. Actual frequencies: for 1657-9700, 1020.0 Hz +/- .01% (panel legend 1 kHz) and 120.00 Hz +/- .01%; for 1657.9800,1000.0 and 100.00 Hz +/- .01%. Applied Voltage: 0.3 V rms maximum. Ranges: Pushbutton selection with automatic front-panel guidance. Three basic ranges (best accuracy, see table) of 2 decades each, for each parameter. Automatic extensions to min and max, as tabulated. SERVICE POLICY QuadTech policy is to maintain product repair capability for a period of five (5) years after original shipment and to make this capability available at the then prevailing schedule of charges. Table of Contents 1.1 PURPOSE 1-1 1.2 GENERAL DESCRIPTION 1-1 1.3 CONTROLS, INDICATORS, AND CONNECTORS 1-1 1.4 ACCESSORIES 1-1 1.1 PURPOSE. in keeping with the long-life circuitry inside. Glass-epoxy The 1657 Digibridge digital impedance meter embodies circuit boards interconnect and support high-quality com use of a microprocessor and other LSI circuitry to ponents to assure years of dependability. provide excellent performance at low cost. Adaptability to any common ac power line is assured by A few clearly labeled pushbuttons and the versatile the removable power cord and the convenient line-voltage built-in test fixture make this instrument a model for con- switch. Safety is enhanced by the fused, isolating power venience. Measurement results are clearly shown with dec- transformer and the 3-wire power connection. A compre imal points and units, which are automatically presented to hensive functional description is given in Theory, Section 4 assure correctness. Display resolution is 5 digits for R, C, Electrical and physical characteristics are listed in Specifi and L (4 for D or Q) and the basic accuracy is 0.2%. cations at the front of this manual, dimensions in Installa Long-term accuracy and reliability are assured by the tion, Section 2. Controls are described below, and their use measurement system. It makes these accurate analog in Operation, Section 3. measurements over many decades of impedance without a single calibration or trimming adjustment (not even in 1.3 CONTROLS, INDICATORS, AND CONNECTORS. original manufacture). . The built-in test fixture, with a pair of plug-in adaptors, Figure :-1 shows the front panel conrols and indicators. receives any common component part (axial-lead or radial- Table 1-1 identifies them with descriptions and functions. lead) so easily that insertion of the DUT is a one-hand Similarily, Figure 1-2 shows the rear panel and Table 1-2 identifies t . . I . Identifies and describes the rear panel controls and connec operation. True 4-terminal connections are made automat .ically. Extender cables and other accessories are available and describes the rear panel controls and connectors. for measurements at a distance from the Digibridge. 1.4 ACCESSORIES. Gen Rad makes several accessories that enhance the use 1.2 GENERAL DESCRIPTION.fulness of this instrument. Two extender cables facilitate Convenience is enhanced by the arrangement of testmaking connections to those devices and impedance stan fixture on the front ledge, with push buttons farther for-dards that do not readily fit the built-in test fixture. A ward and display behind. The display panel is inclined and remote test fixture (used with BNC adaptor and cable recessed to enhance visbility of digital readouts and modeassembly) provides convenience and relatively easy main indicators. These indicators serve to inform and guide the tenance, and saves wear on the built-in test fixture. All of operator as he operates the simple controls. these test-fixture accessories provide for true 4-terminal The instrument stands on a table or bench top. Theconnections (and guard) to the device being measured, sturdy metal cabinet is attractively and durably finished,without appreciable reduction in measurement accuracy. Other useful accessories are offered, such as standards for checking the performance of the Digibridge. Refer to Table 1 -3 and Section 5. INTRODUCTION 1-1 1-2 INTRODUCTION INTRODUCTION 1-3 1-4 INTRODUCTION 2.1 UNPACKING AND INSPECTION. If the shipping carton is damaged, ask that the carriers agent be present when the instrument is unpacked. Inspect the instrument for damage (scratches, dents, broken parts, etc.). If the instrument is damaged or fails to meet specifications, notify the carrier and the nearest GenRad field office. (See list at back of this manual). Retain the shipping carton and the padding material for the carriers inspection. 2.2 DIMENSIONS Figure 2-1. The instrument is supplied in the bench configuration, i.e., in a cabinet with resilient feet for placement on a table. The overall dimensions are given in the figure. 2.3 POWER-liNE CONNECTION. The power transformer primary windings can be switched, by means of the line voltage switch on the rear panel, to ac. commodate ac line voltages in either of 2 ranges, as labeled, at a frequency of 50 or 60 Hz, nominal. Using a small screwdriver, set this switch to match the measured voltage of your power line. I f your I ine voltage is in the lower range, connect the 3-wire power cable (P/N 4200-9625) to the power connector on the rear panel (Figure 1-2) and then to the power line. The instrument is fitted with a power connector that is in conformance with the International Electrotechnical Commission publication 320. The 3 flat contacts are surrounded by a cylindrical plastic shroud that reduces the possibility of electrical shock whenever the power cord is being unplugged from the instrument. In addition, the center ground pin is longer, which means that it mates first and disconnects last, for user protection. This panel connector is a standard 3-pin grounding-type receptacle, the design of which has been accepted world wide for electronic instru. mentation. The connector is rated for 250 V at 6 A. The receptacle accepts power cords fitted with the Belden type SPH-386 connector. The associated power cord for use with that receptacle, for line voltages up to 125 V, is Gen Rad part no. 4200-9625. It is a 210-cm (7 ft), 3-wire, 18-gage cable with connector bodies molded integrally with the jacket. The connector at the power-line end is a stackable hammerhead design that conforms to the Standard for Grounding Type Attachment Plug Caps and Receptacles, ANSI C73. 11-1966, which specifies limits of 125 V and 15 A. This power cord is listed by Underwriters Laboratories, Inc., for 125 V, 10 A. If the fuse must be replaced, be sure to use a slow blow fuse of the current and voltage ratings shown on the rear panel, regardless of the line voltage. INSTAllATION 2-1 If your line voltage is in the higher range selectable by the line voltage switch, use a power cord of the proper rating (250 V, 15 A) that mates with both instrument and your receptacle. It is possible to replace the hammerhead connector on the power cord that is supplied with a suitable connector. Be sure to use one that is approved for 250 V, 15 A. A typical configuration is shown in Figure 2-2. 2.4 LINE-VOLTAGE REGUlATION The accuracy of measurements accomplished with precision electronic test equipment operated from ac line sources can often be seriously degraded by fluctuations in primary input power. line-voltage variations of +/-15% are commonly encountered, even in laboratory environments. Although most modern electronic instruments incorporate some degree of regulation, possible power.source problems should be considered for every instrumentation setup. The use of line-voltage regulators between power lines and the test equipment is recommended as the only sure way to rule out the effects on measurement data of variations in line voltage. 2.5 TEST-FIXTURE CONNECTIONS. 2.5.1 Test Fixture on the Digibridge. Because an unusually versatile test fixture is provided on the front shelf of the instrument, no test-fixture connection is generally required. Simply plug the device to be measured (DUT) into the test fixture, with or without its adaptors. For details, refer to paragraphs 3.1, 3.2. Accessories can be attached to extend and adapt the test fixture, as described below. 2.5.2 Remote Test Fixture. Connection of the DUT at a remote test fixture requires proper adaptors and cable connections from the Digibridge. Obtain the following accessories. (See Table 1-3.) BNC Adaptor 1689-9601 BNC Cable Assembly 1689-9602, or equivalent Remote Test Fixture 1689-9600, or equivalent handler or special fixture. This remote test fixture functions like the one supplied on the Digibridge. True Kelvin connections are made at the points of contact with the DUT leads. Install as follows: a. Remove any adaptors, if present, from the test fixture. b. Plug the BNC adaptor into the basic test fixture with the BNC connectors facing forward. lock the connection with the 2 captive thumb screws. (The screws must be seated to complete the ground connection.) c. Connect the cable assembly to the adaptor on the Digibridge and to the remote test fixture as indicated in Table 2-1. NOTE User provided cables and/or remote test fixtures can be used, particularly if the DUT is to be handled automatically. See paragraph 3.7 for comments on cable and fixture capacitance. 2.5.3 The 1657-9600 Extender Cable (Banana Plugs). The accessory extender cable 1657-9600 is available to connect to DUTs that are multiterminal, physically large, or otherwise unsuited for the built-in test fixture. This cable is particularly convenient for connecting multiterminal components with binding posts that accommodate banana plugs. Use the following procedure to install the extender cable on the instrument. a. Remove the adaptors, if present, from the test fix tu re. b. Plug the single-connector end of the extender cable into the Digibridge test fixture so that its blades enter both slots and the cable lies away from the display panel. lock the connector with the two captive thumb screws. c. Note the color coding of the five banana plugs. Be sure that the low terminals (both potential and current) connect to one end of the DUT and the high terminals to the other end. Connect guard to a shield if any, but not to either end of the DUT. 2-2 INSTAllATION P-(potential, low) = Black/white I-(current, low) = Black P+(potential, high) = Red/white I+(current, high) = Red Guard = Black/green 2.5.4 The 1688-9600 Extender Cable (Type 874 Connectors). The accessory extender cable 1688-9600 can be used to connect a DUT that is multiterminai, physically large, or otherwise unsuited for the built-in test fixture. This low-capacitance cable is used, for example, to connect type-874 connected impedance standards or a special test fixture. Make connections as follows: a. Remove the adaptors, if present, from the test fixture. b. Plug the single-connector end of the extender cable into the Digibridge test fixture so that its blades enter both slots and the cable lies away from the display panel. Lock the connector with the two captive thumb screws. c. Using the branched end of the cable, connect to the DUT with careful attention to the following color code. The cable tips are type 874 coaxial connectors, which mate with a broad line of components and adaptors. Notice that the 2 wires with red must connect to the same end of the DUT, through a coaxial tee if the DUT is a 2-terminal device; the 2 wires labeled with black, connect to the other end, similarly. Connect the outer (shield) contacts to the shield or case of the DUT only if it is isolated from both ends of the DUT. EXTENDER CABLE COLOR CODE RED AND RED: 1+, current drive to high end of DUT. RED AND WHITE: P+, potential connection to same. BLACK AND BLACK I-, current return at DUT low. BLACK AND WHITE: P-, potential connection to same. OUTER CONTACTS: G, guard connection to shield or case. 2.6 EXTERNAL BIAS. Figure 2-3. WARNING To minimize electrical shock hazard, limit bias to 30V. Bias voltage is present at connectors, test fixtures and on capacitors under test. Capacitors remain charged after measurement. Do NOT leave instrument unattended with bias applied. Full bias voltage appears on test leads, bias-voltagesource terminals, and on the leads of the component being measured. Capacitors that have been charged are dangerous until properly discharged; the user must follow safe procedures to assure discharge. For safety, all personnel operating the instrument with bias must be aware of the hazards, follow safe procedures, and never leave the equipment unattended with bias voltage applied. 2.6.1 Basic Bias Connections. In order to measure a capacitor with dc bias voltage applied, connect an external voltage source, as follows: a. Attach the remote test fixture or an extender cable as described in paragraph 2.5. Observe the color coding explained there. INSTALLATION 2-3 b. Connect a suitable bias voltage source (see below) in series with the 1+ connection, basically as shown in the diagram, with the following details. With the Remote Test Fixture. Disconnect the red coded BNC cable end from the remote test fixture and connect one end of plain BNC cable there instead. Connect the red coded BNC cable end to the negative terminal of the bias voltage source. Connect the remaining free end of the plain BNC cable to the positive terminal of the bias voltage source. Connect the DUT to the test fixture in the usual way. With 1657-9600 Extender Cable (Ban