GouldDSO400u 电路图.pdf

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1、 Digital Storage Oscilloscopes Operators Manual Gould 400 Series RadioFans.CN 收音机爱 好者资料库 Gould 400 Series Digital Storage Oscilloscopes Operators Manual Copyright1990 Gould lnc., Instruments Division (Gould Electronics Ltd.) RadioFans.CN 收音机爱 好者资料库 400 Operators Manual Contents Introduction Getting

2、Started 1 Advanced Features 2 The Menus 3 Performance Checking 4 Waveform Processing 5 Battery Unit Operation 6 Alphabetical Summary 7 Appendix 1 Error Messages A1 Appendix 2 Specification A2 Appendix 3 Remote Operation A3 Appendix 4 Front the 400 the 420 and the 450. All versions can be fitted with

3、 a battery unit which provides the instrument with a fully automatic built in Nickel Cadmium battery and charger which allows uninterrupted operation of the DSO in the event of an AC supply failure and complete operation independent of an AC supply. Obtaining a trace is especially simple - just conn

4、ect the signal and press the Auto Setup button - the 400 does the rest. Having obtained a trace, readily accessible datum lines and a cursor make it easy to take automatic timing and voltage measurements directly from the display. On the 420 and 450 models, the waveform processing function increases

5、 the power of the cursor measurements in terms of both capture and post storage analysis and measurement functions. The innovative use of ergonomically designed pressure sensitive push button controls provides a combination of precision and flexibility for ease of operation. More advanced features o

6、f the 400 series include a com- prehensive range of menu-controlled functions. For example, the Display and Trigger menu operates features such as the trigger delay and pre-trigger display functions. The pre-trigger display function allows the signal prior to the trigger point to be captured and dis

7、played. Three complete traces can be stored for future use and recalled to the display via the Save Trace and Recall Trace menus respectively. With the built in battery back up facility, these will be retained even when the instrument is switched off. In addition to the above features, the 420 and 4

8、50 instru- ments have a built in 4 colour plotter and a battery backed Real Time Clock. This provides a simple and convenient method of obtaining permanent hard copy plots of the screen display. The plots will contain the date and time of acquisition together with the date and time of plotting. The

9、450 has all the features of the 420 and has a signal bandwidth of 50MHz and an extra timebase range of 50ns/div. Numbers circled in the text refer to the controls shown on the front panel picture in Appendix 3. Getting Started 1.1-1.1.6 400 Series Operators Manual 1.1 Safety and Power Requirements t

10、hey should be removed only by suitably qualified personnel for maintenance and repair purposes. 1.1.1 International Safety Warning (as required for I.E.C. 348 Cat I) This instrument has been designed and tested in accordance with IEC publication 348, and has been supplied in a safe condition. This m

11、anual contains information and warnings which must be observed to keep the instrument in a safe condition. The instrument should not be switched on if it is damaged and it should not be used under wet conditions. For the correct and safe use of this instrument it is essential that both operating and

12、 service personnel follow generally accepted safety procedures in addition to the safety precautions specified in this manual. Whenever it is likely that safety-protection has been impaired, the instrument must be made inoperative and be secured against any unintended operation. Qualified maintenanc

13、e or repair personnel should be informed. Safety protection is likely to be impaired if, for example the instrument shows visible damage or fails to perform the intended measurements correctly. WARNING: Removing the covers may expose voltages in excess of 8000V at the side of the display tube; these

14、 may be present for up to one minute after the instrument has been disconnected from the power source. 1.1.4 Ventilation and Dust The instrument relies on forced air cooling via a fan and ventilation slots. Adequate ventilation can usually be achieved by leaving a 75mm (3 gap) around the instrument.

15、 The instrument should not be operated in dusty environments. If the CRT filter requires cleaning it can be easily removed by pressing in its right hand edge as shown by the moulded arrow. 1.1.5 Operating Temperatures The instrument is designed to be operated in an environment having an ambient temp

16、erature of between 0 and 50 degrees C, (0 to 45 degrees if the battery unit is fitted) and to operate with full accuracy between 15 and 35 degrees C. Note: Direct sunlight, radiators and other heat sources should be taken into account when assessing the ambient temperature. The instrument may occasi

17、onally be subjected to temperatures between 0 and -10C without degradation of its safety. 1.1.2 Grounding THE INSTRUMENT MUST BE GROUNDED. AC The instrument must be operated with a protective ground connected via the yellow/green conductor of the supply cable. This is connected to the instrument bef

18、ore the line and neutral connections when the supply plug is inserted into the socket on the back of the instrument. If the final connection to the supply is made elsewhere, ensure that the ground connection is made before line and neutral. DC If the unit is disconnected from the AC supply, and powe

19、red from an isolated DC source or the internal battery unit, the unit will not be grounded. Independent provision must be made to maintain the case at a safe potential, by grounding the safety ground terminal on the DSO rear panel. The safety ground terminal is connected to the instrument case, to t

20、he ground of the input signals (outer of the BNC connectors), and also internally to the negative side of the DC supply. 1.1.6 Power and Frequency Requirements The instrument uses less than 85V A (200V A if battery unit fitted) and operates from line voltages of 90V to 130V, and 190V to 265V, at 45

21、to 400Hz. Under the extreme conditions of 90V and 45Hz, the instrument will still operate correctly even if there is a half cycle dropout in the line supply. The instrument may be powered from a direct current supply in the range 12V to 33V. The unit cannot be damaged by applying power to both input

22、s simultaneously. Before connecting the instrument to the supply, ensure that the rear panel AC supply voltage selectors are set to the appropriate voltage. Access to the voltage selector can only be made if the AC supply connector is removed, and is by hinging open the panel connector from its top

23、edge. The selector barrel can then be moved to the required setting. This same operation provides access to the AC supply fuse, which must be changed to suit the supply voltage as shown in table 1.1. 7. The AC power connection is via a standard IEC, CEE 22 connector and the DC power input is via the

24、 supplied 0.25 spade connector (Gould part No. 457839.) See appendix 4 for polarity details. WARNING: Any interruption of the protective ground conductor inside or outside the instrument is likely to make the instrument dangerous. Intentional interruption is prohibited. Signal connections to the ins

25、trument should be connected after the ground connection is made and disconnected before the ground connection is removed, i.e. the supply lead must be connected whenever signal leads are connected. 1.1.3 Live Parts The instrument should not be operated with covers removed. The covers protect the use

26、r from live parts and 400 Operators Manual Getting Started Figure 1.2a Single Function Buttons Figure 1.2b The Toggles Figure 1.2c The Pressure Sensitive Buttons 400 Series Operators ManualGetting Started 1.1.7-1.4.1 1.3 Start-Up Display When switched on with the POWER button (1) . the instrument wi

27、ll go through its automatic self-calibration sequence and then display information similar to that shown in Figure 1.3. CAUTION: The negative DC terminal is connected to the safety ground terminal and the instrument case. Care should be taken to avoid ground loops when, for example, the instrument i

28、s used in a vehicle and powered by that vehicles supply. 1.1.7 Fuse Requirements The fuse arrangement shown in table 1.1. 7 must be followed, and additionally in the UK, a 3A fuse (5A if the battery unit is fitted) should be fitted in the line supply plug . Supply Slow Blow Gould Suggested types. Vo

29、ltage Fuse Rating Part No Manufacturer/Type No IEC (ULlCSA) DSO 230V 0.5A (0.6A) 457452 BeswickrrDC488, Littlefuse/239, Schurter/FSP 115V lA (1.2A) 457454 BeswickrrDC488, Littlefuse/239 Schurter/FSP 12VDC 5A (6A) 457979 HRC type Beswick/S505, Wickman 19181 BATTERY UNIT 230V lA (1.2A) 457454 Beswickr

30、rDC488, Littlefuse/239, Schurter/FSP 115V 2A (2.5A) 457455 BeswickrrDC488, Littlefuse/239, Schurter/FSP Figure 1.3 Start-Up Display The trace is visible across the centre of the screen. At the top will be the sensitivity of the two input channels and the timebase speed. It any input is inactive, inf

31、ormation for that channel will not be displayed. Users with no previous experience of a DSO will find that the 400 responds like a conventional Real Time Oscilloscope while it is repetitively triggered, but in the absence of further valid triggers, it retains the last trace for continuous display. T

32、able 1.1.7 Fuse ratings Note: For different DC voltages, the DC fuse rating multiplied by the voltage used should equal60W. e.g. at 30V a 2A fuse is required. For additional safety under extreme fault conditions, the DC fuse is a high rupture current (HRC) type. This fuse should have a 1500A break c

33、apacity. 1.4 Obtaining a Trace See Figure 1.4 1.4.1 AUTO SETUP To display an input signal, connect it via either the CHI socket (9) or the CH2 socket (12) and press AUTO SETUP (24) . Assuming youve applied a regular signal, say a 2kHz sine- wave with an amplitude of perhaps 5V peak to peak, it will

34、almost immediately be represented on the display. An example is shown in Figure 1.4.1. It the display is very dim or has completely disappeared see section 1.8.1. 1.2 Using the Buttons see appendix 3 There are three types of buttons. The first type usually have only one function: when pressed, that

35、one function will be activated e.g. AUTO SETUP (24). See Figure 1.2a. The second type are toggles: each press of the button either switches something on or off e.g. Add (10) , or selects the next item in a sequence e.g. Off/On/lnv (13) . See Figure 1.2b. AUTO SETUP will attempt to arrange the displa

36、y so that two to five complete cycles appear, with the amplitude set so that the height of the trace is between two and five screen divisions. Also, it selects Auto trigger to ensure that the screen is frequently updated and a trace will be visible. The third type are Pressure Sensitive: the effect

37、caused depends upon how hard the button is pressed. For example, a gentle press of a Posn (8) button will move the trace slowly. If the button is pressed harder, the trace will move more quickly. See Figure 1.2c. If signals are connected to both channels, the highest amplitude takes priority. Gettin

38、g Started 1 .4.2-1 .5.1 400 Series Operators Manual 1.4.3 Coupling (AC/DC/Gnd)(14) These buttons control the type of coupling between the input signal and the instrument. DC is the most generally applicable, and AUTO SETUP will normally set this control to DC, where possible. The input impedance is

39、I M ohm in parallel with a capacitance of 28pF. AC This is used to remove any DC component from input signals. Suitable input signals (i.e. the bandwidth) are from 4Hz to 20MHz. Gnd The input signal is internally disconnected from the inputs and the amplifier grounded. A OV reference signal is displ

40、ayed. DC The input signal is directly coupled to the instrument so all frequency components of the input signal will be displayed. The bandwidth will be from DC to 20MHz. Figure 1.4 Obtaining a Trace 1.5 Horizontal Adjustments Figure 1.4.1 An AUTO SETUP Display Figure 1.5 Horizontal Controls 1.4.2 C

41、hannel Selection (Off/On/lnv) (13) A channel may be switched on or off with its Off/On/Inv button. If the channel is on, its trace can be displayed in either normal or inverted mode. Off The channel is deactivated. On The trace is a true representation of the input signal. Inv The input signal is in

42、verted before being displayed. If there is any DC component in the signal this will also be inverted and could cause the trace to disappear from the screen. Such an unwanted DC component can be removed by selecting AC coupling. Any vertical shift applied to the trace is not inverted. The trigger poi

43、nt remains at the same point on the waveform regardless of inversion. 1.5.1 TIME/DIVISION TIME/DIV (33) These buttons control the sweep rate of the trace. The timebase can be varied from 100ns/div to 50s/div in a I, 2, 5 sequence of values. The button marked ns decreases the time/div, the button mar

44、ked sec increases the time/div. With a timebase of say 200/Ls, each horizontal screen division represents 200/Ls worth of signal. The timebase is shown near the top of the display - e.g. TB=200/Ls. Assuming a 2kHz signal is applied as mentioned earlier, when the timebase is set to 500ms/div, an inte

45、resting phenomenon may appear: an alias. Getting Started 1 .5.2-1 .6.3 400 Series Operators Manual 1.5.2 Aliases are 20mV to 50V per division at the probe tip. See Section 3.4.1. If the Uncal light is on, then these buttons vary the sensitivity continuously. See Section 1.6.3. An alias is a false im

46、age. The instrument is a digital oscilloscope and so takes frequent samples of the input signal in order to update the trace. Thus, if the signal frequency is higher than the sample frequency, one sample will be taken from a particular point on the waveform and the next sample may be taken from a po

47、int slightly further along on a subsequent cycle. It will then display the wave as being much slower than it really is. See Figure 1.5.2. This effect is only likely to occur if there are more than 100 cycles of waveform across the screen. Figure 1.5.2 Alias Generation There is a Max/Min glitch detec

48、tion feature which can be used to detect aliases. With dot join on, this usually results in a filled-in wave envelope being seen on the screen, indicating a high frequency. See Section 3 A. 1.5.3 Position Position (26) These buttons move all traces to the right or left. The position of the cursor (S

49、ection 2.4) is fixed in relation to the trace so it will move with the applied shift. With x-magnified traces (Section 1.5.4), the cursor can be off the part of the trace displayed on the screen. To bring it back into view use the CURSOR buttons(5). 1.6.2 Position Posn (8)These move their respective traces up and down the display. If Trace Hold is on (Section 2.2) or a S/Shot capture has been made, any part of the trace which was captured off-screen vertically will be sh