Inverter

The Inverter circuit changes the dc voltage from the Preregulator to ac for use by the supplies that are connected to the secondaries of T940. The output of the Preregulator circuit is applied to the center tap of T940. Power-switching transistors Q940 and Q942 alternate conducting current through R941 from the primary circuit common to the Preregulator output line. The transistor switching action is controlled by T942, a saturating base-drive transformer. When the instrument is first turned...

Miller Sweep Generator

The Miller Sweep circuit is composed of Q630A, Q630B, Q631, and associated timing components. The circuit operates to hold the charging current to the timing capacitor at a constant value. When a capacitor is charged in this manner, the rise of voltage across the capacitor is linear rather than exponential. Field-effect transistors Q630A and Q630B are matched devices. As such, the lDSS (drain current with gate-to- source shorted) characteristics of each are nearly identical. FET Q630B acts as a...

1 Check Adjust Power Supply DC Levels and Ripple R946 and R952

Review the information at the beginning of the Adjustment Procedure before starting this step. a. Remove the High-Voltage shield (see the HighVoltage Shield removal procedure in Section 6) if the instrument has the Current Limit board (A19). If the instrument has the Preregulator board (A18), remove the protective shield on the bottom of the Main board (A10) to access the test point pads. To avoid electric shock and instrument damage when checking either the Head Room Voltage or the...

Troubleshooting Techniques

The following procedure is arranged in an order that enables checking simple trouble possibilities before requiring more extensive troubleshooting. The first four checks ensure proper control settings, connections, operation, and adjustment. If the trouble is not located by these checks, the remaining steps will aid in locating the defective component. When the defective component is located, replace it, using the appropriate replacement procedure given under Corrective Maintenance in this...

Repackaging For Shipment

If the instrument is to be shipped to a Tektronix Service Center for service or repair, attach a tag showing owner (with address) and the name of an individual at your firm that can be contacted. Include complete instrument serial number and a description of the service required. Listings of Tektronix Sales and Service offices, both domestic and international, are located at the back of the manual following the tabbed Accessories page. Save and reuse the package in which your instrument was...

Cathode Ray Tube

Breakage of the crt may cause high-velocity scattering of glass fragments (implosion). Protective clothing and safety glasses should be worn. Avoid striking the crt on any object which may cause it to crack or implode. When storing a crt, either place it in a protective carton or set it face down on a smooth surface in a protected location with a soft mat under the faceplate. To remove the crt, perform the following steps 1. Disconnect four deflection-plate wires...

Internal Trigger Switching Logic

Internal trigger-selection signals to the Trigger Pickoff Amplifier (Diagram 2) are produced in a logic circuit composed of U305B, U305C, U305D, U315B, and U315C. The TRIGGER INT Source switch (S305), in conjunction with CH 1-BOTH-CH 2 switch (S317), determines the internal trigger source selected. When either the CH 1 or CH 2 Internal Trigger signal is selected by S305, the selected channel will be the internal trigger source. When VERT MODE is selected as the internal trigger signal, the...

External Zaxis And Probe Adjust

Leveled Sine-Wave Generator (Item 2) P6120 Probe (provided with instrument) a. Connect the leveled sine-wave generator output via a T-connector and two 50-i2 cables to the EXT Z-AXIS INPUT connector on the rear panel and to the CH 1 OR X input connector. b. Adjust the generator controls to produce a 5-volt, 50 kHz display. Channel 1 POSITION VERTICAL MODE CH 1 VOLTS DIV CH 1 VOLTS DIV Variable c. CHECK For noticeable intensity modulation. The positive part of the sine wave should be of lower...

Initial Control Settings

Channel 1 POSITION VERTICAL MODE CH 1 VOLTS DIV CH 1 VOLTS DIV Variable INVERT Channel 1 AC-GND-DC Channel 2 AC-GND-DC HORIZONTALMODE SEC DIV SEC DIV Variable X10 Magnifier MULTIPLIER CAL detent Normal (button out) DC GND Midrange NO DLY 0.1 ms CAL detent Off (knob in) < X1 1. Adjust Horizontal Amplifier Gain (R752 and R733) a. Connect 0.1-ms time markers from the time-mark generator via a 50-ii cable and a 50-i2 termination to the CH 1 OR X input connector. Connect the generator Trigger...

Current Limit Board Configuration

The Power switch (S901 ) connects the line voltage to the instrument through line fuse F901 and transient suppressor VR901. Suppressor VR901 protects the instrument from large voltage transients. High-frequency line noise is attenuated by C901. The Preregulator circuit converts the ac-power-source input voltage to a regulated dc voltage. A triac is used as a switch to conduct current during a controlled period of the inpuMine-voltage cycle so that energy to be used by the Inverter circuit is...

Performance Conditions

The following electrical characteristics (Table 1-1) are valid for the 2213 when it has been adjusted at an ambient temperature between +20 C and +30 C, has had a warm-up period of at least 20 minutes, and is operating at an ambient temperature between 0 C and +50 C (unless otherwise noted). Items listed in the Performance Requirements column are verifiable qualitative or quantitative limits, while items listed in the Supplemental Information column are either explanatory notes, calibration...

Troubleshooting Aids

Complete schematic diagrams are located on tabbed foldout pages in the Diagrams section. The portions of circuitry that are mounted on each circuit board are enclosed within heavy black lines. Also within the black lines, near either the top or the bottom edge, are the assembly number and name of the circuit board. Component numbers and electrical values of components in this instrument are shown on the schematic diagrams. Refer to the first page of the Diagrams section for definitions of the...

General Description

In the following overall functional description of the 2213 Oscilloscope, refer to the basic block diagram (Figure 3-1) and to the detailed block diagram (Figure 9-4) located in the Diagrams section of this manual. In Figures 3-1 and 9-4, the numbered diamond symbol in each major block refers to the appropriate schematic diagram number. Signals to be displayed on the crt are applied to either the CH 1 OR X input connector or the CH 2 OR Y input connector. The signals may be coupled to the...

Preregulator Circuit Board

To remove the Preregulator circuit board, perform the following steps 1. Remove the High-Voltage shield see the HighVoltage Shield removal procedure . 2. Remove two screws securing the Preregulator board mounting brackets one at the rear-top of the frame and one on the right side near the back corner of the frame . 3. Remove the securing screw through the access hole of the clear plastic shield from the top of the Preregulator board at the front-right corner. 4. Disconnect four wire connectors...

Trigger Level Comparator

The Trigger Level Comparator circuit determines both the trigger level and slope at which a triggering signal is produced. Transistors U460E and U460B form a comparator circuit. It compares the trigger signal level applied to the base of U460E with the reference dc level set by the TRIGGER LEVEL potentiometer R455 and applied to the base of U460B. Slope switching is accomplished by controlling the biasing of transistor pairs U460A-U460D and U460C-U460F. When AUTO or TV FIELD triggering is...

Preregulator Board Configuration

The Power Input circuit converts the input ac-source voltage to filtered dc for use by the Preregulator. The POWER switch S901 connects the ac-supply source through fuse F901 to bridge rectifier CR904. The bridge full-wave rectifies the source voltage, and its output is filtered by C909. Input surge current at the time of instrument power-up is limited by thermistors RT901 and RT902. Initially their resistances are high, but as they warm up, their resistances decrease and they dissipate less...

Preparation

Test equipment items 1 through 9 in Table 4-1 are required to accomplish a complete Performance Check. At the beginning of each subsection, in both the Performance Check Procedure and the Adjustment Procedure sections, there is an equipment-required list showing only the test equipment necessary for performing the steps in that subsection. In this list, the item number that follows each piece of equipment corresponds to the item number listed in Table 4-1. This procedure is structured in...

Auto Intensity

The purpose of the Auto Intensity circuit, shown in Diagram 6, is to keep the intensity of the trace on the crt at a constant level with changing sweep speeds and trigger signal repetition rates. In conventional oscilloscopes, as the duty cycle of the displayed trace changes, the intensity will vary. The Auto Intensity circuit compensates for this effect by increasing the Z-Axis Drive voltage for low Sweep duty factors. The elements of the Auto Intensity circuit consist of four blocks the...