JPS62502631A - Signal processing device with level matching circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Signal processing device with level matching circuit The present invention relates to a signal processing device of the type defined in the preamble of claim 1.

Level matching circuits are used in signal processing equipment to It is used to achieve matching for the dynamic domain of signal processing within the system.

A device of this type is known from German Patent Application No. 2 162 337. . In this known device, a resistor of an operational amplifier connected as a potentiometer is used. The ratio of resistors is varied by various switches. In this circuit, on one side The input resistance changes at different switch positions, while the high resistance Significant problems arise with respect to the seal r in the signal processing of the resistor. Furthermore, the input side has a potential is not applied and the compensation voltage that adjusts the DC voltage is not supplied as is. .

The present invention according to claim 1 can be realized particularly compactly (can be easily held in the hand). (possible) signal processing device of the type mentioned at the beginning, which enables a simple configuration inside the measuring device. It is to provide all the necessary information.

The present invention provides an input amplifier operated according to the operational amplifier type, in which the input voltage range is The switching occurs only in the virtual earth region due to the change, so the switching The switching point cannot be disturbed by stray potentials or by high potentials to be switched. It is based on the recognition that there is no such thing.

The requirement for high dynamic range and broadband at the same time and high resistance? The requirement for a reliable input resistance results in a calibration line with a high resistance. arise. This is because this configuration requires compensation capacity. be. Two preamplifiers are used to reduce component and adjustment costs. separate voltage divider stages, and one decimal voltage divider and one step voltage divider are used. The latter can be constructed with a relatively low resistance.

In order to keep the amplification degree as small as possible, the input fundamental division (Eingangsg rundteilung) is avoided. For this purpose, it is advantageous to As in the example, the input side is not connected to the non-inverting input side of the buffer amplifier, but is connected to the potentiometer. Individually configured operational amplifiers connected in a data-like fashion were used. This is it and operate with an effective resistance at one input without suffering potential attenuation. This has the advantage of being possible.

The summing point realized in this way on the input side of the amplifier is not suitable for another reason. Always advantageous. This summing point indicates that the circuit constant is correct (if set, the potential is It is not connected to the ground, and at the same time forms a virtual ground. Therefore advantageously this addition There are additional points that can be used for DC shifting or automatic zero calibration. It is possible to supply a suitable regulated voltage. In this case, it is also necessary to stabilize the DC voltage of the amplifier. Fully automatic zeroing and calibration is possible if properly connected. It will become a reality. In addition, the If the requirements are met and the computer is connected, the AC and DC voltage components of the signal are Fully automatic measurement of minutes will be realized.

Due to the virtual ground on the input side of the operational amplifier configured in potentiometric fashion, Is the requirement of high and constant input resistance for all switch stages met? This makes it possible to realize two input current dividers.

Since amplifiers are capable of current control, the method of the present invention of dividing the input current is advantageous. It will be done.

All voltage divider resistances are calculated according to the rules for parallel circuits of resistors, with the input side The resistor is connected between the virtual ground point of the potentiometer-connected amplifier and the base on the input side. Can be switched between quasi-potential and quasi-potential. Due to the parallel circuit, the voltage amplification degree of the amplifier can be increased accordingly. reduced. A fixed resistor is placed on the input side so that the various °T” type resistors on the input side resistor configuration is present on the input side with the exception of an integrated series resistor, where the parallel shunt is There is no need to consider it when calculating the current flowing through the width switch.

The present invention provides reference potentials and virtual voltages for input and output signals of operational amplifiers. It is based on the recognition that these systems are integrated in terms of thinking. Therefore, the input signal is completely replaced with relative to a reference or virtual earth potential in relation to a connection point that is maintained independent of state. Thus, the ratio (and therefore the input resistance to the amplifier) is constant.

In contrast, the amplification of an operational amplifier circuit is determined by a partial resistor connected to virtual ground. It is only specified and can be switched accordingly.

An additional working resistance on the input side is used to obtain electrical reliability and It acts to reduce the current associated with the connection point.

Also in this case, compared to the otherwise customary divider circuit, the value for the capacitance is Minimum. Here are some other benefits of this highly advantageous configuration: year Very little precision resistance is required.

All strays of the conductor paths leading to the components and circuits defined by the geometry. Free capacity remains constant. This is because all components are all switches. connected in the same way to earth at all times. That is, on the one hand, a virtual arch on the other hand, and to the actual ground on the other hand.

The preresistance has a relatively high resistance (approximately IMΩ). This means that the associated capacitance will also withstand pressure. If configured, it means that the operation will be extremely reliable.

The input capacitance σ is approximately 20 pF, which is relatively small.

In the most sensitive stage, the amplifier has a higher resistance than an amplifier configured with a non-inverting connection. It is possible to operate without a basic split of 6dB despite the resistance of The first amplifier further increases the amplification capacity, advantageously by a factor of about five.

Simple construction of the switch (only one contact change per divider stage each time) and Therefore advantageous embodiments using integrated analog switches in CMO8 technology is possible.

The load on the signal input side is constant.

The current in the return path is constant.

The actual resistance to level matching in the operational amplifier feedback network is: It consists of one or more resistors in combination, and the number of resistors is the minimum overall. Therefore, the load caused by the parallel circuit to be measured is also minimal. Therefore, the prefix With a safety resistance of Totality is maximized.

In known signal processing devices, the zero point shift of the measurement signal, that is, the softness of the DC voltage component. In particular, it is necessary to supply variable voltage levels to the internal circuit points of the measurement amplifier. costly measures are needed. In that case, the effect of each shift will be It is very difficult to judge in the first place, and there is a gradual varnish of voltage that should be supplied depending on the application. It is necessary to carry out curry-trading, and it must also be consistent with the appropriate use. No. In particular, with automatic zero compensation, even one lift voltage in an individual amplifier stage can influence the result. Moreover, to completely compensate all the DC voltage reference points, it takes many times and is costly. Another disadvantage is that it can only be realized using such expensive means.

The problem with the solution according to claim 6 as a particularly advantageous embodiment of the invention is that An input circuit of the type mentioned at the beginning, which allows zero-point compensation or calibration of the The goal is to provide a path.

The present invention provides a potentiometer-connected signal amplifier in the form of an operational amplifier. When using a It is based on the recognition that voltages that are independent of the signal stage are possible. this circuit At the point, the potential is not guided towards the reference level with respect to the input voltage, so the compensation voltage The signal has no disturbing effect on the pressure source. The signal between the input signals that appears fundamentally Since the signal detection can be carried out regularly between the two sides of the DC voltage amplifier, The requirement that no lift occur is correspondingly reduced.

In measuring equipment with digital signal processing, DC voltage compensation is advantageously As such, it is carried out. That is, the DA converter is controlled by the digital signal processing section. of the operational amplifier formed potentiometrically connected to the virtual earth point via An analog signal of constant amplitude is generated which is fed to the input side, and the AD variation of the mower is via the converter to the analog input of the measuring device of the digital evaluation section connected downstream. A varying compensation signal is supplied until the output signal "zero" appears.Subsequent processing There are two methods for The analog compensation signal may be continuously supplied or the analog compensation signal may be cut off for these measurements. Only the digital values corresponding to the compensation signal should be supplied in analog with the digital result Will it be corrected?

In an advantageous embodiment of the invention, for calibration, ie special linearization of the analog inputs, The signal path described above is used for this purpose. A series of measurements that can then be used for calibration In the time period during the process, the digital signal changes preferably in equally spaced steps. An analog signal is provided which is expressed via a DA converter using the signal. Increased measurement The digital output signal appearing at the output side of the AD converter downstream connected to the width converter is The input signal is compared with the original step-changing digital input signal at each stage. The signals and output signals are commonly stored in memory according to a table. It's like this All digital signal values can be corrected using a table, resulting in a reduction in the total input area. This ensures linear signal transmission over the area.

In another advantageous embodiment of the invention, it is also used for the alternating voltage characteristics of the input. I can do it. Calibration is carried out separately for the various measurement areas in an advantageous manner. The signal representing the position of the input divider is then stored in a This is used to specify the digital value corresponding to each measurement area.

Further advantageous embodiments of the invention are specified in the subclaims and below. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail with reference to the drawings in connection with the description of advantageous embodiments of the invention.

1a to 10 show the steam circuit of the input divider with amplifier in various switching states. Figure 2 shows the entire divider stage with amplifier and calibration capabilities. is a diagram showing a circuit of FIG. 3 is a circuit diagram showing the details of the calibration section. In this case, an operational amplifier connected in the form of a potentiometer is connected downstream. Figures 1a to 1c can be used as a reference for the principle of the input divider. The details are clear from FIG.

In Figures 1a to 10, following the complex input resistor (R11 in parallel with C11) What about the resistor/capacitor combinations R13/C13 and R14/C14? The inverting input of the operational amplifier v1 can be connected individually or in common depending on the measurement area to be connected. Connected in parallel to the capacitor combination R12/'C12 on the power side (summing point S). a summing point S and an amplifier v1 with input reference point or output reference point; It is clear that it is connected to the non-inverting input side (+) of the resistance capacitor set combination R15/'C15 (all resistors/'capacitor combinations in parallel circuit) The summing point Sft amplifier V1 is connected to the output side of the summing point Sft amplifier V1.

The summing point S and the reference point for input and output signals are actually are not different, so these points can be accepted as unified regarding the input signal. Rukoto can. From the input side, the ratio does not change by switching these points. However, the ratio of the resistance from the output side to the summing point S - the resistance from the input side to the summing point S The amplification ratio (UA/UE) determined by the associated value varies. stray electricity The signals are similarly undisturbed by switching.

Next, the detailed embodiment shown in FIG. 2 will be described. Shielded coaxial input slot An input signal is supplied to the circuit via a cable, for example a BNC cable. pickpocket The cable is first connected to the front protection resistor R11, which has a large value. must have.

It must have high voltage resistance and high precision.

In parallel with this, the acceleration input controller, which also has to be of high voltage resistance for safety reasons. Capacitor S C1m' is connected. This is advantageous in multi-layer cards where two formed by the capacitor coating. The surfaces of these coatings are inside the multilayer car. are on correspondingly different planes and separated by the base material as a dielectric. It is formed by two metal sheets, separated from each other. In this way, otherwise Special capacitors, which have always been expensive, are realized in a very safe configuration without additional costs You can.

Furthermore, the components at this direct input must have a corresponding creep section and also a conductor curve. The fixing hole spacing must be r.

An actuation type switch (BAS) is connected downstream of the front resistor. This is the device It is also used as a closing switch.

In the first, illustrated position # (OFF), the device is shut off and the input resistance of the device is The resistor is formed by a resistor R11 and a resistor R12 connected in series.

In the second position DC (direct current), the preresistance is calibrated divided via the switch connected to the device. At the same time, mechanically in parallel, in the RAS-Ko-switch Another switcher moves and it turns on the device.

In the third position of RAS, namely position CD (earth), the preresistor R11 As in the case of the switch position OFF, it is combined into the input resistor together with the auxiliary resistor R12. , while at the same time the switch bridge of BASO 2 connects the input side of the calibration divider to the input resistor. Connected to the central measuring ground via a resistor R13’i equivalent to RIO, the position GRO Simulate the input side of the measuring device connected to earth at the UND.

Finally BAS17) In the fourth position, namely position AC (alternating current), the pre-resistor RI Is O the voltage-resistant coupling capacitor CIO? to the calibration divider circuit.

At the same time, mechanically in parallel, another switch ζ in the RAS-Ko switch - moves and signals this position to the digital evaluation of the switch position.

Coupling capacitors operate in high-resistance circuits, so they greatly reduce the coupling time constant. The requirement of shortness is met.

Therefore, by connecting the calibration line and ° of the preresistor, the measurement area decimal switch (M' BSD) to connect resistors R13 and R14 to virtual ground or real ground as follows: It becomes possible to connect to the actual ground. In other words, the potentiometers listed in the table The amplification for the video preamplifier formed in the shimometric manner is determined by the calibrated divider. Theoretically explained in the description and combination with the second stage measurement area switch As required in the switch position machining or 11. be.

Capacitors C13 and C1 are connected to current dividing resistors R13, R14, and R15, respectively. 6, C14 and C17 to C15 are connected in parallel. These are mentioned above Completely form the compensation capacitor. Trimmer capacitor and solid capacitor respectively The combination of improves the adjustability and temperature coefficient.

The MBSD is formed from a 2-level switch with 11 stages.

Special clothing Showa 62-502631 (5) The two switch bridges calibrate the current divider resistor in the first switch position. via a switch to the potentiometric input of preamplifier v1. fifth place From the beginning, the second short circuit node ζ- connects the resistor R14 to the central measuring ground, while the resistor The resistor R13 is also connected to the input side of the potentiometer type, where the eighth step Two resistors are connected to the measurement ground from the switch position to the open position. Ah By arranging all of the switch contacts opposite the switch contacts in the configuration shown, the two It becomes possible to realize all the necessary connection variants using slider bridges. .

As mentioned above, the summing point is a very important part of the entire analog switching circuit in relation to the system. It is a point. It may simply be used as a virtual ground for the current divider circuit. Not only that, but at the same time we have the following important system point f:1li3E: DA converter (DA) for automatic zero correction at the input point of the entire active amplifier path Addition point for the supply of correction current generated by C).

Electronic compensation for AC voltage signals with shifted zero and superimposed DC voltage Addition points for the supply of correction currents generated by DACs to generate voltages (electronic AC coupling).

A microprocessor-controlled switch MK switches the central of the operational amplifier Vl with a simulation resistor R35 connected to the measurement ground. Offset voltage measurement point.

A summing point which supplies the signal current coming from the calibration line via the switch 5lt-.

This summation point of the potentiometrically configured amplifier is therefore Used to automatically calibrate logging systems. Adjust the operating format setting before adding points. The measuring divider also has remarkable long-term stability and reliability, with low temperature Starting from the fact that it is a passive network consisting of precision elements with coefficients. and automatic calibration permanently, i.e. before each measuring sequence of intermittent measuring operations during the operating period or before each individual measurement point (in each case during the sampling process) In other cases (before sample extraction), automatic zero point correction and also AD converter It becomes possible to calibrate the linearity of the entire system including gold. With this system, micropro From the processor - for example, a 12-bit signal - to the DA converter (○) k, the signal input The power side is supplied with a DC voltage step stepwise within the entire transmission area, so that the DA The bits are passed through the converter to the microprocessor for comparison and thus the calibration table It can also be controlled so that it is supplied for storage. Automatic calibration is detailed. is done like this: Phase ■: The micro processor operates switch S32 to the operating position and turns it on. offset voltage via resistor R35 Phase ■: The microprocessor knows which measurement area is input to B. Since it is known through the AS coding, the microprocessor Identify the source resistance of the calibration line. In this way, the microprocessor Measure the offset voltage corresponding to the respective source resistance using the measured value of phase ■. and route it to phase m via the DAC.

Phase ■: When the switch 831 is opened, the microprocessor The calibration signal is then re-entered into the operational amplifier path by the microprocessor via the ADC. Supplied in digital form to the service provider. The microprocessor is stored in the corresponding calibration table Then, the signal to be measured arriving at phase ■ can be properly evaluated in terms of calibration. I will do it.

Phase ■: Switch 832 is open and switch S31 is closed during measurement. You can start the phase. During Phase H, all DACs are connected to Phase H. The zero-point correction voltage is supplied to ensure optimal use of all DAC functions. You will be able to do things.

The introduction of this automatic calibration system has two important advantages. On the other hand, this , the zero-point stability of the entire analog stage and the guarantee of temperature y + 1 ft, and This made it possible to limit the cost of these stages. For example, the second There is no need to use precision resistors in the calibration voltage divider. Semiconductor devices and passive devices The temperature of the IJ raft no longer plays a significant role. But the decisive advantage is , is stable for long periods of time and is therefore traditionally unthinkable in this class of low-cost equipment. We were able to achieve a high level of reliability that was previously unavailable.

In addition to such price analysis and reliability aspects, we also consider the origin of this system. There are a number of reasons that promise special uses for science. For example, if a high-speed DA converter is used It's time to

Next, the input section (for one channel) shown in FIG. 2 will be explained in detail.

The analog signal appearing on the input side E is connected to a high-resistance circuit with a parallel protective capacitor C31'r. It is supplied to the actuation type switch Sl via a pre-protective resistor R31e. Operation type The switch is in the operating state "direct current voltage coupling (DC)", °alternating voltage coupling (AC)" - - input terminal is shorted (ground)” using a mechanical slider switch. Rukoto can. At the same time, switch the device through this switch to the switch position "off" Therefore, a suitable set of contacts that can cut off the power supply voltage is easy to understand. It is not shown for this reason.

Actuation type switch consists of coding switches mechanically connected in parallel . This switch connects the microcomputer connected after the digital processing section. , the respective position of the switching slider is changed from line °D'' to three separate lines L1 to L. Transmission is made by connecting to one of 3. In the fourth position, no connection occurs It is transmitted by

In addition to the actuation type switch, one further measuring range switch S21 (per channel) /'S22 is provided. This switch is used to change the input/signal amplitude to another stage. It can be matched to the level condition. Each measuring area switch has two main It consists of main parts S21 and S22. It is the measurement area switch whose first part is decimal. P is made up of an 11-stage multiple slider switch consisting of a switch S21. measurement area The switch changes the amplification and attenuation of the input signal with respect to the summing point. It is used for this purpose, through a resistor network that can be used.

The following table shows the measurement area position MBS, the associated values for the vertical coefficient n1 reference voltage Yb, Decimal attenuation value al, amplification degree v1 of the buffer amplifier stage, its nominal output voltage Ual, channel The attenuation value a2 before the channel amplifier and the amplification degree v2 of each channel amplifier are shown in ing.

MBS Vb al vl Ual a2 v2 (V/DIV) (V) (V ) 0.0.1 0.06 1 5 0.30 1 7.81250.0.2 0. 12 1 5 0.60 1 3.906250, G5 0.30 1 5 1 ．． 5 0.4 3.906250.1 0.6 1 53.0 0.2 3.9 06250.2 1.2 0.05 10 0.6 1 3.906250.5 3.0 0.05 10 1.5 0.4 3.906251.0 6.0 0.05 10 3.0 0.2 3.906252.0 12 0.05 1 0.6 1 3.906255.0 30 0.05 1 1.5 0.4 3 ．． 9062510.0 60. 0.05 1 3.0 0.2 3.9062 520.0 120 0.05 1 6.0 0.1 3.90625 Output voltage is uniformly 2.345V.

The resistors and capacitors in the divider circuit are shown in the basic circuit above for their representation. Corresponds to the way the figure is displayed.

Another knob connected in parallel to the divider capacitor is designated with respect to the reference numeral. An additional ``'' is added.

Using a calibrated multi-solexor M'lzc formed by an analog switch, the Separated from the analog signal input side Ek addition point and connected afterward via the DA converter DAC'r. It can be controlled by the connected microcomputer CPtJ.

At this time, a DC voltage signal is supplied to the summing point S in stages via the resistor R34e. follow A DC voltage signal is fed to the input side of the amplifier chain and the entire amplifier chain is The microcontroller passes through the AD transformer and evaluates it as a digital signal. returned to the computer. Since the microcomputer generated the target signal itself, , it stores the incoming real signal in the calibration table and thus calculates the calibration multiplex. Evaluation of the incoming real signal during the next measurement process, connecting the signal source again In this case, any necessary corrections can be made according to the stored correction table.

The addition point S has a decisive influence on the versatility of the device. Additional points are potential formed by the virtual earth of a DC voltage broadband amplifier connected in a dimeter-like manner. Ru. This amplifier automatically corrects the DC voltage signal coming from the DA converter. and can be applied for automatic calibration. At the same time it is a decimal measurement area A hypothetical for amplifier v1 with a calibration line connected via switch 321 Used as a ground.

Measuring amplifier Vlil-1, push-pull formed by discrete semiconductor components formed by a Brissozi amplifier and as a current divider, the calibration component is Cooperative with a decimal measuring range switch connected in potentiometer style, representing a divider. and amplify the input signal.

The measurement amplifier thus measures the entire decimal stage of 5x, 0.5x, 005x A calibration line is separated from a step switch connected downstream of amplifier V1. A large number of separated measurement areas can be formed as a calibration line without significant costs. A separate one for use in high-resistance parts of the input circuit A decimal division in one measurement area stage is generated by a decimal measurement area switch. It will be done. A buffer amplifier is formed in the level matching stage 1; 0.5; 0.2 between them. An additional division is performed after the first measuring amplifier V1, which

The reason is that a low resistance source is already present due to the output of this amplifier and Therefore, the stepped resistor is a stepped switch 522ff which eliminates the need for a compensation capacitor. Therefore, it is selected.

Therefore, the stage switch 822 is connected between the measuring amplifier ■1 and the following measuring amplifier v2. is inserted and achieves damping with a coefficient of 1; 0.5; 0.2' . In parallel to the step switch 822 - a single step slide switch 8 not shown; 22 further contact rows are provided, whereby the signals generated by the DA converter the DC voltage output signal corresponds to the step switch position on the input side of the summing point; It is matched to the respective required voltage level (respective current level).

Connected downstream to this stage switch is again a broadband DC voltage amplifier. The total level of the input side of the fully parallel AD converter is The measurement amplifier V2 amplifies according to the Bellwin P request. Level of use The pins have a width of approximately 2.5v.

The stage divider containing amplifier v2 has one step in cooperation with the first stage divider. Controlled differently by switch S22. It is true that the amplifier stage v2 has the same potential. In a capacitive vacuum connected in parallel to the working resistor, Omitted. The tap between resistors R22 and R23 connects the slider switch. It is connected to the connection terminals grouped together on one side of the circuit S22, and this point is Corresponding to the increasing reduction in the amplification factor of amplifier v2, first the output of amplifier v1, then and the connection point of the two resistors R21 and R22, then the connection point of the two resistors R21 and R22. together with a parallel resistor forming a voltage divider leading to a reference potential. However, that Resistor R, which together with resistor R27 determines the amplification coefficient of operational amplifier V2, 23 takes out the input voltage. Depending on the selected amplification degree, resistors R22 and R2 The connection point with 3 is a series circuit formed from resistors R24, R25 and R26. Added to various taps. This consists of switches S1 and 821. For the configured input voltage range of the device, by adjusting the settings of the divider accordingly. The required voltage step-up or step-down is achieved.

Sampling as high as possible so that signals with high bandwidth can be evaluated A post-connected parallel AD converter with the frequency (sampling rate) is used. It will be done. This so-called "flash converter" has a parallel-connected reference on the input side. formed by a fast comparator chain that is quantized via a voltage divider. It will be done. At the sampling time, if one of the connominators (8-bit change There are 256 connomitors in the converter), each time just increasing the base voltage value. Undertakes the identification of signals that are turning or falling. These Konomire A coding circuit, which is post-coupled with a It is transmitted in an 8-bit wide binary code, and it is transmitted as a signal at the sampling frequency. It is taken out at the output 9111 of the AD converter at the timing.

The digital data generated by the AD converter is transmitted to a microcomputer connected afterward. controlled by the computer's CPU. 8-bit CPU is on i-yRA M, includes ROM and oscillator and series interface.

The CPU is used as a central computer with the following functions: That is, Kiese All commands input from -t are stored in internal or external program memory. Processes the program according to the current program and reads the signal supplied from the high-speed register. and evaluate them according to various regulations, convert them, store them in memory and convert them into other signals. Compare and analyze and display it at the end and interface accordingly image screen or graphics processor, printer or another interface. transfer to the face processor via BUS. For DC voltage compensation and calibration Data is stored in the memory indicated by "Cal". Here, bit by bit Also included is a table that provides a comparison of Et-°C.

What is remarkable about the circuit device described above is that the two-stage slide switch has a contact point. directly adjacent to an electrical element whose contacts are to be switched at all times be. between the contacts of two consecutive stages in the direction of operation of the switch, on the board. An amplifier is provided, and the air distance generated by the amplifier is bridged by the operating element of the switch.

to the divider switch in the operating direction, independently of the divider switch - but the structure A correspondingly configured actuation type switch is connected upstream.

This type of circuit allows for spatially optimal oscillography with short connection distances. The input circuit is configured so that mutual signal interference can be suppressed to a small extent.

This circuit works even if the slider switch is located on the outer edge of the board with U-shaped contact elements. Even if it acts along or is arranged adjacent to the central area of the substrate, It is also particularly suitable for symmetrical configurations of IC2 channels. For placement along the outer edge, further benefits. That is, the decoupling of the two channels is effectively realized, and the Particularly in the region separating the two channels, for example a current supply circuit or a DA For two channel amplifiers, such as processors that perform signal processing after conversion. If the circuit elements that correspond to each other are arranged, mutual signal interference will not actually occur. That's what it means.

Then, if the remaining elements of this type of structure were miniaturized accordingly, - It becomes possible to place a complete oscillographic circuit on one board and therefore Measuring device for processing electrical input signals with significantly different amplitude ranges The important prerequisite is that it can be held in the hand. At that time, an electric cycle The size of the circuit board - even when it is constructed in multilayer technology there is a substantial It must be taken into account that the mounting is determined by the number of possible conductor tracks.

Therefore, it is essential that the length of the conductor path be shortened by the structural arrangement. When measures are taken, a substantial reduction in size is achieved. Such measures , which also positively influences other properties of the device. Because loss and mutual trust This is because signal interference is reduced. In this way, the quality of the signal to be processed is improved This eliminates the need for separate elements, which results in a significant reduction in overall structural size. be revealed.

Figure 2 shows a digital oscilloscope in addition to the amplifier path explained so far. Another group of grooves belonging to is shown in block diagram form, with key 5-Y .

DA converter (DAC), processor with memory (CPU), calibration device (CA L), digital signals from the AD converter (ADC) and LCD indicator are common. Connected to BUS. another, located on the opposite side of the corresponding printed circuit board. The 6-element amplifier/divider path is also indicated by the rectangular block T2. The arrangement is done in a mirror image of the representation in the upper area of the figure. Slider switch Chi81. If S21 and 322 are placed on the edge of the substrate, the drawing shows that the seal P Fold around the dashed line guided along the center of the switch contact, which represents It is thought to have been folded. In this way, the edge of the board with switching contacts on both sides It is now possible to display the position of the switch contacts, where the movable contact elements are Depending on the particular constructional embodiment, it has a figure 8 or Ω shape.

FIG. 3 shows an embodiment of the calibration device in more detail.

During the measurement operation period, an input signal is input from the measurement input side 301 via the changeover switch 302. In the analog processing section, a level matching section 303 having a switchable resistance is used. Processing is performed via an operational amplifier circuit 304 connected to the The control and indication unit 306 receives an indication of the analog measurement value detected there. This is done using manual means.

The operational amplifier 304 has a resistor R that determines the degree of amplification in a potentiometer type connection. 301 and R302, the switching means 303 preferably being connected to the resistor R301. If it is connected or not, this value itself changes as explained above.

To compensate for processing errors in this analog processing path, they are based on linearity error or linearity error. It will be done. This calibration is carried out between individual measurement cycles and adjusted accordingly by the system. Calibration is initiated by the signal °start" which is generated.The calibration is started by 07 is carried out on the measurement area set and adjusted, and at that time the area measurement The switch sends out a digital signal that activates the switching section (block 308). The signal causes the individual resistors included in block 303 to settings are made so that the analog signal is controlled according to the desired signal level.

At the same time, the output signal of the area selection block 307 is the digital address of the RAM 309. Specify. The RAM then stores correction values that act as a compensation in the direction of the desired calibration. is detected in digital form. The output signal of the area selection switch is RA each time. Specify the address of the area in M309. In this case, this signal Contains the high-order bits of the address specification.

The digital signal contained in the addressed memory location of RAM is converted from digital to analog. 310. The analog signal of the AD converter is sent to the operational amplifier 3 via a resistor. 04 is supplied to the virtual 7th point. Therefore, an important advantage is that the correction value is always available. corresponds only to relative errors in each case and is independent of the selected region. Benefits accrue. In this way, the digital values stored in RAM3091C are The information it contains is used optimally.

Furthermore, a direct indication of relative deviations is possible.

will be started. The output ``000'' of the counter 311 is ANDed in the -HIGH'' state. via the inverting input side of gate 3120 to its other input side and to OR gate 313. L”r (1’) Cuts off the low signal to the clock input side. If activated via the As a result, the signal at the corresponding output shifts to the state -LOW.

As a result, the switch 302 is switched and the analog signal is output. The processing path is connected to the output signal of the level generator 314. The level generator A signal is generated in stages that extends over the measurement area of the body. To that extent, the record The bell generator 304 is similarly driven by the digital output signal of the region selection block 307. controlled. The signal “000” appearing on the output side of the counter is passed through the inverter 315. The signal reaches not only the selector switch 302 but also the AND gate 316. this gate passes the clock signal of oscillator 317 to another counter 318 . this counter The output signal of 318 is transferred to the input side of RAM 309 on the one hand and is processed as required. is written or forwarded to multiplexer 319 based on the corresponding signal. Ru. The multiplexer is activated in the operating state "Calibrate" via the corresponding control input. The corresponding digital signal is passed through a DA converter 310Vc. This converter is Generate a compensation signal. Counter 318 determines whether AD converter 305 or When the signal is led to the zero detector 321 via another multiplexer 320, Continue counting until instructed to do so.

A multiplexer 320 is connected to this zero detector 321 in the calibration state and During the measurement operation, the output signal of the AD converter is transferred to the instruction section 306. .

The DA converter has an output signal “0” that is almost within the digital value range that controls the DA converter. It is set so that it is centered. Therefore, the counter 318 calculates its operating cycle. generates a combination voltage of negative to positive value during the cycle. Correct indication value is executed. The output signal of the zero detector, indicating that the zero has occurred, stops the counter 318 and -The input side of the RAM 309 is ”, the reached value of the counter is stored in the addressed memory of the RAM. Be fixed in place. a first value sent from the level generator 314; is the value "0", so in this case, first, the DA converter 3 required for zero point compensation is Ten setting adjustments are retained. The signal on the output side of the D element 323 is the input Reset the counter 318 via ``Reset'' and reset the counter 311 clock. This counter is advanced by the value 1 via the input. In addition, the level generator 314 is set in the first stage so that the generator generates a predetermined fractional portion of the maximum input signal. Send an analog signal.

The final counting state then corresponds to the maximum input signal value of the measurement range in question. Furthermore The output signal of this counter reaches RAM 309 and there the lower bits of the address As a result, as the state of the counter 311 progresses, the intermediate value of the RAM is passed through. Ru. Furthermore, it is subtracted from the value that reaches the digital zero detection. As a result, the zero detector becomes As soon as both values are equal, i.e. the output signal of the AD converter corresponds to the predicted value. , sends out an output signal.

In this way, the predetermined measurement area is scanned pixel by pixel, and the correction table is stored in the RAM 309. As a result, the transmission area of the analog section is stored in RAM3 during measurement operation. It is linearized by a correction signal generated from 09.

The lower pit of RAM 309 is connected to a multiplexer 322 whose settings are adjusted accordingly. Therefore, during measurement operation, the address is specified by the output signal of the AD converter 305. The detection of the correction value then takes place via the measured value itself. Multiple measurement cycles After , the set value is indicated. This is because the measured value is This is because it will continue to change depending on the situation.

According to another embodiment of the invention, only zero point correction is performed via the DA converter 310. and is maintained for each measurement area, while stored in RAM 309. The other incorrect correction value may be determined directly regardless of the conversion of the output signal of the DA converter 310. The values reproduced in the indicator 306 are arithmetically corrected, and the RA is then corrected in accordance with the measurement area. Upon addition of the values addressed to M, the memory contents are arithmetic and digital The signal is then logically combined with the output signal of the area selection section 307.

The invention is not limited to the advantageous embodiments described so far in its embodiment. do not have. On the contrary, the solutions that have been described also in fundamentally different types of embodiments Many variations are possible using .

Report on international research , +1JIN:X To 1’ME 1NTERNATIONAL 5EARC HREPORT 0NUS-A-40342910S107/77 None 100 continuation 95 Table of Contents 2-502631 (11)

Claims (17)

[Claims] 1. A level matching circuit, such as a wide-bandwidth oscilloscope, and amplification A first resistor lined up between the inverting input side (virtual ground) of the operational amplifier and the operational amplifier. an operational amplifier determined by the ratio of the second resistor between the inverting input side and the signal output side of the a signal processing device, wherein the resistor is optionally a complex resistor. There, at least one parallel resistor is provided to the first resistor; The connecting terminal is the signal input side or the connecting point of multiple partial resistors forming the first resistor. the operational amplifier, the second connection terminal forming a virtual ground. switching between the inverting input of the amplifier and the actual reference potential for the input of the amplifier. A signal processing device characterized in that: 2. One fixed resistor is connected to the first resistor, which changes by parallel connection, and the signal input side. 2. The signal processing device according to claim 1, wherein the signal processing device is connected in series to the signal processing device. 3. Claim 1, wherein the switching is performed using a mechanical or electrical switch. Or the signal processing device according to item 2. 4. In claim 1, the switching is performed using an integrated analog switch. 3. The signal processing device according to any one of the above items. 5. The capacitive component of the complex resistance is formed by at least one trimmer capacitor. A transistor having a complex resistance according to any one of claims 1 to 4, No. processing equipment. 6. The level matching circuit includes one operational amplifier, each with a switchable resistor. It consists of two successive stages, the first of which has a high resistance 5. A calibrator according to claim 1 forming a calibration divider. No. processing equipment. 7. The value of the resistor is such that each decimal level match step change causes one resistor to change. It is generated by connecting or cutting off the resistance that previously determined level matching. The belief set forth in any one of the selected claims 1 to 6 No. processing equipment. 8. Claim 1 comprising at least one amplifier, e.g. a level matching circuit. In the input circuit for the signal processing device according to any one of paragraphs 7 to 7, , Shifting the DC voltage and/or correcting individual amplitude values within the transmission window The supply of compensation current for the amplifier summing point is formed by connecting a potentiometer An input circuit device characterized in that the circuit is connected to a virtual ground through a circuit point. 9. The summing point coincides with the circuit point leading the switchable current divider to the level matching section; The changing shunt of the current elimination divider is connected between the summing point and the amplifier input and output sides. 9. The input circuit according to claim 8, wherein the input circuit is switchable between. 10. The power supply depends on the output signal of the amplifier and is fed back by the DA converted signal. 10. The input circuit according to claim 9. 11. The generation of the signal to be fed back is based on a predetermined distribution of the analog output signal of the amplifier. deviation of a predetermined analog input signal from the same predetermined analog output signal. The digital signal stored in memory obtained from the digital signal corresponding to the difference 11. The input circuit according to claim 9 or 10, wherein the input circuit is implemented using a signal. 12. Amplifier calibration is performed in terms of amplitude distributed over a set transmission region. This is done by feeding back different signals at different input signals. The input circuit according to claim 11. 13. A digital value representing the signal to be returned is stored in memory and is obtained from the stored digital value by DA conversion. 12. The input circuit according to any one of items 1 to 12. 14. In memory, the digital values are stored in a variety that covers the configured input signal region. Depending on the input signal amplitude of each The input circuit according to claim 13. 15. The memory can be addressed, at least indirectly, by means of digitized measured values. The value specified and then stored in the addressed memory is transferred to the DA converter. Claim 9, which is a correction value or a corrected value supplied to the summing point via The input circuit according to any one of items 1 to 14. 16. Calibration is carried out using signals representative of the selected measurement area, with different The digital values determined for the measured area are stored in different memories. The input circuit according to any one of claims 9 to 15. 17. Feedback in a multi-stage amplifier is determined from the input of one of the amplifier stages to the first of the amplifier stages. The entry stated in any one of claims 9 to 16 made to the column power circuit.