TWI621856B - Signal measurement apparatus and signal measurement method - Google Patents

Abstract

A signal measuring device has a detecting circuit, a first measuring circuit, a second measuring circuit and a control circuit. The detecting circuit is electrically connected to the object to be tested to generate a detection signal of the object to be tested. The first measuring circuit is electrically connected to the detecting circuit, and generates a first measuring signal according to one of the detecting signal, the first measuring range and the second measuring range, wherein the second measuring range is greater than the first quantity Measuring range. The second measuring circuit is electrically connected to the detecting circuit, and generates a second measuring signal according to the detecting signal and the compensation measuring range, wherein the compensation measuring range is greater than the second measuring range. The control circuit is electrically connected to the first measuring circuit and the second measuring circuit, and controls the first measuring circuit to switch one of the first measuring range and the second measuring range according to the second measuring signal.

Description

Signal measuring device and signal measuring method

The invention relates to a signal measuring device and a signal measuring method, in particular to a signal measuring device and a signal measuring method with adjustable measuring range.

Measuring devices or measuring circuits in electronic devices often require continuous measurement of the power of the dynamic load signal. In general, there are two methods of measuring the auto range or using a constant range. Since the amplitude of the load signal is not fixed, if the automatic gear position is used for measurement, the measurement data is often lost due to frequent replacement of the gear position during the measurement process. However, if a fixed gear is selected for measurement, the unknown dynamic load signal is often unpredictable, so that the dynamic load signal cannot be properly matched with the selected fixed gear. When selecting a gear position that is too high as a fixed gear position, it can measure all the signals, but it will also reduce the measurement resolution and accuracy; otherwise, when the gear position is too low, although it has better resolution Degree, but it is still very likely to cause data loss.

In the case of a digital power meter, the current digital power meter on the market requires the measurement program to use a fixed gear position, so the user must perform a pre-test procedure on the object to be predicted in the normal program test. The highest signal amplitude that can occur. However, in addition to causing inconvenience in use, this method does not ensure that data loss does not occur in the measurement procedure, or that the measurement resolution is lowered by overestimating the highest signal amplitude.

The invention provides a signal measuring device and a signal measuring method, in order to overcome the trouble caused by the unknown characteristics of the signal to be tested in the past.

The invention discloses a signal measuring device, wherein the signal measuring device has a detecting circuit, a first measuring circuit, a second measuring circuit and a control circuit. The detecting circuit is electrically connected to a test object to generate a detection signal of the object to be tested. The first measuring circuit is electrically connected to the detecting circuit, and generates a first measuring signal according to one of the detecting signal, a first measuring range and a second measuring range, wherein the second measuring range is greater than the first measuring range A measurement range. The second measuring circuit is electrically connected to the detecting circuit, and generates a second measuring signal according to the detecting signal and the compensation measuring range, wherein the compensation measuring range is greater than the second measuring range. The control circuit is electrically connected to the first measuring circuit and the second measuring circuit, and controls the first measuring circuit to switch one of the first measuring range and the second measuring range according to the second measuring signal.

The invention discloses a signal measurement method. The signal measurement method includes: electrically connecting a test object to generate a detection signal; generating a first measurement signal according to the detection signal and the set measurement range, and setting the measurement The range is one of a plurality of preset measurement ranges; the second measurement signal is generated according to the detection signal and the compensation measurement range, and the upper limit of the compensation measurement range is not less than an upper limit of any of the preset measurement ranges Determining whether the signal value of the first measurement signal is greater than the upper limit of the current set measurement range; if the signal value of the first measurement signal is greater than the upper limit of the current set measurement range, then according to the second measurement signal The signal value size switches the set measurement range to the other of the preset measurement ranges, and the upper limit of the set measurement range after the switching is greater than the signal value of the second measurement signal.

The above description of the disclosure and the following description of the embodiments of the present invention are intended to illustrate and explain the spirit and principles of the invention, and to provide further explanation of the scope of the invention.

The detailed features and advantages of the present invention are set forth in the Detailed Description of the Detailed Description of the <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> </ RTI> <RTIgt; The objects and advantages associated with the present invention can be readily understood by those skilled in the art. The following examples are intended to describe the present invention in further detail, but are not intended to limit the scope of the invention.

Please refer to FIG. 1. FIG. 1 is a functional block diagram of a signal measuring device according to an embodiment of the invention. As shown in FIG. 1, the signal measuring device 1 has a detecting circuit 12, a first measuring circuit 14, a second measuring circuit 16, and a control circuit 18. The detecting circuit 12 is electrically connected to the first measuring circuit 14 and the second measuring circuit 16. The first measuring circuit 14 and the second measuring circuit 16 are electrically connected to the control circuit 18, respectively.

The detection circuit 12 has a plurality of detection terminals. In this embodiment, the first detecting end E1 and the second detecting end E2 are described. The detecting circuit 12 is configured to obtain the signal to be measured of the object 2 to be measured via the first detecting end E1 and the second detecting end E2. The signal to be measured may be a voltage signal or a current signal, which is not limited herein. The detecting circuit 12 is configured to generate a detection signal according to the signal to be measured.

The first measurement circuit 14 has a plurality of preset measurement ranges. The first measuring circuit 14 is configured to generate a first measuring signal according to the detection signal and the set measurement range. The set measurement range is one of the preset measurement ranges. For example, each preset measurement range is, for example, 0 milliamperes (mA) to 5 milliamperes, 0 milliamps to 20 milliamps, 0 milliamps to 50 milliamps, 0 milliamps to 200 milliamps, and 0 millimeters, respectively. Ampere to 300 mA. The set measurement range can be switched to any of the preset measurement ranges. For example, when the set measurement range is switched to the preset measurement range of 0 mA to 20 mA as described above, and the current of the detection signal is also between 0 mA to 20 mA, this The first measurement circuit 14 can record the current magnitude of the detection signal in the first measurement signal in an appropriate form. Ideally, the signal value of the first measurement signal is the magnitude of the current of the detection signal. The case where the measurement range is set to other preset measurement ranges can be deduced by analogy. It should be noted that the first measurement circuit 14 is used to measure the current for explanation. Those skilled in the art should understand that the first measurement circuit 14 should be understood after reading the specification. The case where the voltage is designed to be measured is not repeated here.

The second measuring circuit 16 is electrically connected to the detecting circuit 12. The second measurement circuit 16 has a compensation measurement range. The upper limit of the compensation measurement range is not less than the upper limit of any of the preset measurement ranges. For example, the compensation measurement range is, for example, 0 mA to 300 mA and covers all of the preset measurement ranges. Alternatively, the upper limit of the compensation measurement range may also be greater than 300 milliamperes, which is not limited herein. The second measuring circuit 16 is configured to generate a second measuring signal according to the detection signal and the compensation measurement range. As described above, when the magnitude of the current of the detection signal is between 0 mA and 300 mA, the second measurement circuit 16 can record the current of the detection signal in the second measurement in an appropriate manner. Among the signals. Ideally, the magnitude of the signal value of the second measurement signal at this time is the magnitude of the current of the detection signal. Similarly, in another embodiment, the signal value of the second measurement signal may also be the voltage level of the detection signal.

The control circuit 18 is electrically connected to the first measurement circuit 14 and the second measurement circuit 16. The control circuit 18 is configured to instruct the first measurement circuit 14 to switch the set measurement range to the other of the preset measurement ranges according to the first measurement signal and the second measurement signal. For each of the foregoing numerical ranges, it is assumed that the set measurement range is, for example, 0 mA to 20 mA, the compensation measurement range is, for example, 0 mA to 300 mA, and the magnitude of the detected signal is, for example, 60 mA. . At this time, the magnitude of the current of the detection signal is greater than the upper limit of the set measurement range, so the signal value of the first measurement signal is only 20 milliamperes. The magnitude of the current of the detection signal is less than the upper limit of the compensation measurement range. Therefore, the signal value of the second measurement signal should ideally be 60 milliamperes. Therefore, when the control circuit 18 determines that such a situation occurs, the control circuit 18 instructs the first measurement circuit 14 to adjust the set measurement range to an upper limit value of at least 60 milliamps according to the magnitude of the signal value of the second measurement signal. Preset measurement range. In this embodiment, the control circuit 18, for example, increases the upper limit of the set measurement range to 200 milliamps.

In an embodiment, when the control circuit 18 instructs the first measurement circuit 14 to switch the set measurement range to the other of the preset measurement ranges at the first time, the control circuit 18 is further based on the first time. The second measurement signal compensates for the first measurement signal of the first time. Thereby, the first measurement signal at the first time is avoided or cannot be recognized by the back end circuit.

2 is a functional block diagram of a signal measuring device according to another embodiment of the present invention. Figure 2 illustrates a specific embodiment of a signal measuring device. In the embodiment shown in Fig. 2, the signal measuring device 1' is used to measure the magnitude of the signal value of the signal to be measured. In Fig. 2, the signal measuring device 1' further has a communication channel 13 and a coupling circuit 19. The coupling circuit 19 has a pulse transformer 192 and a photocoupler 194. The relevant details are well known to those of ordinary skill in the art and will not be described herein. One end of the pulse transformer 192 is electrically connected to the first measuring circuit 14 and the second measuring circuit, and the other end of the pulse transformer 192 is electrically connected to the control circuit 18 via the communication channel 13 . One end of the photocoupler 194 is electrically connected to the first measuring circuit 14 and the second measuring circuit, and the other end of the photocoupler 194 is electrically connected to the control circuit 18 via the communication channel 13 .

The control circuit 18 has a digital signal processor 182 and a Field Programmable Gate Array (FPGA). The digital signal processor 182 is electrically coupled to the field programmable gate array 184. The digital signal processor 182 accesses the first measurement signal or the second measurement signal via the field programmable gate array 184, and the digital signal processor 182 adjusts the first measurement circuit 14 or the first via the field programmable gate array 184. Two measuring circuit 16.

In the embodiment shown in FIG. 2, the first measurement circuit 14 has a first amplifier 142, an anti-aliasing filter 144 and a first analog-to-digital converter 146. The first amplifier 142 and the anti-aliasing filter 144 are electrically connected to the first analog-to-digital converter 146. The input end of the first amplifier 142 is electrically connected to the detection circuit, and the output of the first analog-to-digital converter 146 is electrically connected. The pulse transformer 192 is connected. The first amplifier 142 is controlled by the digital signal processor 182 via the aforementioned circuit structure. In an embodiment, the control circuit 18 is configured to adjust the gain of the first amplifier according to the magnitude of the signal value of the first measurement signal and the signal value of the second measurement signal to switch the set measurement range to the preset amount. One of the measurement ranges.

Further, the second measurement circuit 16 has a second amplifier 162, an anti-aliasing filter 164 and a second analog-to-digital converter 166. The second amplifier 162 and the anti-aliasing filter 164 are electrically connected to the second analog-to-digital converter 166. The input end of the second amplifier 162 is electrically connected to the detecting circuit, and the output of the second analog-digital converter 166 is electrically connected. The pulse transformer 192 is connected. The second amplifier 162 is controlled by the digital signal processor 182 via the aforementioned circuit structure. In an embodiment, the control circuit 18 is configured to adjust the gain of the second amplifier according to the magnitude of the signal value of the first measurement signal and the signal value of the second measurement signal to switch the compensation measurement range.

From another perspective, the first measurement signal or the second measurement signal is, for example, a sampled and quantized digital signal of the detection signal. More specifically, the first measurement signal and the second measurement signal are synchronized at the sampling timing, and the dynamic range corresponding to the first measurement signal and the dynamic range of the second measurement signal may be Is the same or different. Since the digital signal processor 182 knows the measurement range of the first measurement circuit 14 and the measurement range of the second measurement circuit 16, even when the dynamic range of the first measurement signal and the dynamic range of the second measurement signal Differently, the digital signal processor 182 can obtain the information associated with the first measurement signal from the second measurement signal according to the relative relationship between the upper limit of the first measurement range and the upper limit of the second measurement range. As described above, when the first measurement circuit 14 switches the set measurement range at the first time point, the correlation value of the first measurement signal at the first time point or the correlation value before and after the first time point may not be recognized or There may be flaws. At this time, the digital signal processor 182 can convert the correlation value of the first measurement signal at the first time point according to the information of the second measurement signal at the first time point, and compensate the first measurement signal accordingly.

On the other hand, in this embodiment, the detecting circuit 12 further includes a gear shifting sub-circuit, the gear shifting sub-circuit has a first resistor R1, a second resistor R2, a first relay RL1, a second relay RL2, and a third Relay RL3 and fourth relay RL4. The first resistor R1 is electrically connected to the first detecting end E1 and the voltage dividing node ND, respectively. The two ends of the second resistor R2 are electrically connected to the second detecting end E2 and the voltage dividing node ND, respectively.

The output end of the first relay RL1 is electrically connected to one of the input ends of the first amplifier 142. The plurality of input ends of the first relay RL1 are electrically connected to the first detecting end E1, the voltage dividing node ND and the external input end E3, respectively. The output of the second relay RL2 is electrically connected to the other input of the first amplifier 142. The plurality of input ends of the second relay RL2 are electrically connected to the second detecting end E2, the voltage dividing node ND and the external input end E3, respectively. The output of the third relay RL3 is electrically connected to one of the inputs of the second amplifier 162. Two of the plurality of input ends of the third relay RL3 are electrically connected to the first detecting end E1 and the external input end E3, respectively. The output of the fourth relay RL4 is electrically connected to the other input of the second amplifier 162. Two of the plurality of input ends of the fourth relay RL4 are electrically connected to the voltage dividing node ND and the external input terminal E3, respectively. The external input terminal E3 is used for the user to provide a user-defined signal source. In practice, the external input terminal E3 may have one or more physical ports, which are not limited herein.

The gear shifting sub-circuit provides the user with more measurement range selection by selectively turning on the various inputs of the relay and their outputs. The resistance value of the first resistor R1 and the resistance value of the second resistor R2 can be adjusted according to the circuit impedance and the actually required measurement range, and are not limited herein. On the other hand, the detecting circuit 12' further has protection circuits 122', 124', 126'. The protection circuit 122' is configured to prevent the first detection terminal E1 and the second detection terminal E2 from being short-circuited. The protection circuit 124' is used to prevent the user from providing excessive current to burn the circuit. When the second resistor R2 has a small resistance value, the protection circuit 126' is used to prevent the second signal R2 from being damaged by the signal to be measured having a large current.

Please refer to FIG. 3. FIG. 3 is a functional block diagram of a signal measuring apparatus according to another embodiment of the present invention. In the embodiment shown in FIG. 3, the signal measuring device 1" is used to measure the voltage level of the signal to be measured. The circuit structure of the signal measuring device 1" is substantially similar to the signal measuring device in FIG. 1', the difference is that the signal measuring device 1" is composed of a resistor R1"~R4" and a diode D1~D4 to form a voltage dividing circuit, and is via a programmable gain amplifier ("GA"). The detection signal is provided according to the output signal of the voltage dividing circuit. The programmable gain amplifier 128" is controlled by the digital signal processor 182. In other words, the digital signal processor 182 can adjust the set amount by adjusting the gain of the first amplifier 142 or the gain of the second amplifier 162, respectively. In addition to the measurement range and the compensation measurement range, the digital signal processor 182 can adjust the set measurement range or the compensation measurement range by adjusting the gain of the programmable gain amplifier 128".

According to the above, the present invention provides a signal measurement method. Please refer to FIG. 4 for description. FIG. 4 is a flowchart of a method for measuring a signal according to an embodiment of the invention. In step S101, the object to be tested is electrically connected to generate a detection signal. In step S103, a first measurement signal is generated according to the detection signal and the set measurement range, and the measurement range is set to one of a plurality of preset measurement ranges. In step S105, a second measurement signal is generated according to the detection signal and the compensation measurement range, and an upper limit of the compensation measurement range is not less than an upper limit of any one of the preset measurement ranges. In step S107, it is determined whether the signal value of the first measurement signal is greater than the upper limit of the current set measurement range. In step S109, when it is determined that if the signal value of the first measurement signal is greater than the upper limit of the current set measurement range, the set measurement range is switched to the preset according to the signal value of the second measurement signal. Set one of the measurement ranges.

In an embodiment, when the set measurement range is switched to the other of the preset measurement ranges at the first time, the first measurement signal of the first time is compensated according to the second measurement signal of the first time. The relevant details are as described above, and the detailed description thereof will not be repeated here.

In addition, in practice, the set measurement range can be adjusted according to the signal value of the first measurement signal. The preset measurement ranges respectively correspond to different multiple measurement threshold values. In an embodiment, it is first determined whether the first measurement signal is not less than a measurement threshold corresponding to the current set measurement range. When it is determined that the first measurement signal is not less than the measurement threshold corresponding to the current set measurement range, the switching set measurement range is the other of the preset measurement ranges. The upper limit of the adjusted set measurement range is larger than the upper limit of the set measurement range before adjustment. For example, the current set measurement range is, for example, 0 mA to 20 mA, and the corresponding threshold is 16 mA. When the signal value of the first measurement signal is 17 mA, the switching measurement range is 0 mA to 50 mA. Thereby, the set measurement range can be pre-adjusted corresponding to the signal value range of the first measurement signal to prevent the detection signal from being clipped.

In practice, the compensation measurement range can also be adjusted according to the measurement situation. Please refer to FIG. 5 for description. FIG. 5 is a flowchart of a method for measuring a signal measurement according to another embodiment of the present invention. . In this embodiment, the second measuring circuit has a first compensation range and a second compensation range, and the compensation measurement range is one of the first compensation range and the second compensation range. The upper limit of the first compensation range is limited to less than the upper limit of the second compensation range. The first compensation range corresponds to the first threshold value. In step S201, when the compensation measurement range is the first compensation range, it is determined whether the signal value of the second measurement signal is smaller than the first threshold. In step S203, when it is determined that the signal value of the second measurement signal is not less than the first threshold, the compensation measurement range is switched to the second compensation range.

For example, the first compensation range is, for example, 0 mA to 300 mA, the first threshold is 290 mA, and the second compensation range is, for example, 0 mA to 500 mA. When the foregoing digital signal processor 182 determines that the signal value of the second measurement signal is equal to or greater than the first threshold, the digital signal processor 182 instructs the second measurement circuit 16 to switch the first compensation range to the second compensation. range. Thereby, the signal measuring circuit can avoid the distortion of the second measuring signal as much as possible within the circuit capability, thereby avoiding the dilemma that the first measuring signal cannot be compensated from the second measuring signal.

In addition, in addition to the upper limit of the set measurement range, the upper limit of the set measurement range can be appropriately adjusted according to the actual condition of the signal measuring device and the signal measuring method provided by the present invention. A measured signal has a better resolution. Referring to FIG. 6 to illustrate one of the methods, FIG. 6 is a flowchart of a method for measuring a signal according to a further embodiment of the present invention. In this embodiment, the first measurement range and the at least one second measurement range are defined in the plurality of preset measurement ranges. The upper limit of the current set measurement range is greater than the upper limit of the first measurement range and the upper limit of the at least one second measurement range, and the upper limit of the at least one third measurement range is greater than the upper limit of the current set measurement range, the first measurement The upper limit of the range is greater than the upper limit of at least one second measurement range. In step S301 of the signal measurement method, the effective reference value of the first measurement signal in the down-conversion reference time interval is obtained. In step S303, it is determined whether the effective reference value is smaller than the upper limit of the first measurement range or smaller than the upper limit of the at least one second measurement range. In step S305, when it is determined that the effective reference value is less than the upper limit of the first measurement range or less than the upper limit of the at least one second measurement range, the set measurement range is switched to the first measurement range.

The effective value is, for example, a root mean square value (RMS value) of a plurality of consecutive sampling points of the first measurement signal. For example, the current measurement range is, for example, 0 mA to 200 mA, the first measurement range is 0 mA to 50 mA, and the second measurement range is 2, 0 mA to 20 mA, respectively. With 0 mA to 5 mA. When the rms value of the first measurement signal in the down-conversion reference time interval is 30 milliamperes, the aforementioned digital signal processor 182 instructs the first measurement circuit 14 to adjust the set measurement range to the first measurement range. , that is, 0 mA to 50 mA. The significance of this is that the effective value is used, for example, to represent a long-term trend change of the first measurement signal, that is, when the effective value falls within a certain measurement range, it represents a subsequent sampling of the first measurement signal. The size of the points is likely to fall within this measurement range. Therefore, when the effective value falls within a measurement range smaller than the current set measurement range, the digital signal processor 182 instructs the first measurement circuit 14 to adjust the set measurement range to obtain a better resolution, and In the case of making a decision with reference to the effective value, the adjusted set measurement range is not too small and the detection signal is cut off.

Continuing the foregoing, when the rms value of the first measurement signal in the down-conversion reference time is 15 milliamperes, the digital signal processor 182 further instructs the first measurement circuit 14 to adjust the set measurement range to the first measurement. The range is 0 mA to 50 mA. This is to avoid excessively rapid adjustment of the set measurement range, while the current value or voltage value of the detection signal suddenly rises so that the peak value of the detection signal is cut off.

Please refer to FIG. 7 to illustrate another method for lowering the set measurement range. FIG. 7 is a flowchart of a method for measuring a signal according to still another embodiment of the present invention. In step S401, it is determined whether the first measurement signal conforms to the signal template in the template reference time. In step S403, when it is determined that the first measurement signal meets the signal template in the template reference time, the adjustment measurement measurement range is the first measurement range in the preset measurement range. Wherein, the preset measurement range further defines at least one second measurement range, where an upper limit of the first measurement range is not less than a maximum value of the first measurement signal, and an upper limit of the first measurement range is less than at least one The upper limit of the second measurement range.

It should be noted that the definitions of the first measurement range and the second measurement range in the embodiment shown in FIG. 7 are different from the first measurement range and the second measurement in the embodiment shown in FIG. 6. The definition of the scope. The signal pattern refers to, for example, the magnitude of the change of the signal or the trend of the rise and fall of the signal waveform, etc., which is generally known to those skilled in the art and can be defined after reading this specification. limit. On the other hand, the template reference time is equivalent to an observation time, and is also not limited here. When the first measurement signal meets the signal template in the template reference time, the first measurement signal should conform to a certain rule. Therefore, after the signal template is properly selected, it can be determined that the voltage value or the current magnitude of the first measurement signal that matches the signal template is located in a certain range. At this time, the set measurement range can be adjusted to the first measurement range in this embodiment. In another aspect, the upper limit of the first measurement range in this embodiment is the maximum of the first measurement signals of all the preset measurement ranges and is greater than the maximum of the first measurement signal. value.

Please refer to FIG. 8 for description. FIG. 8 is a flowchart of a method for measuring a signal according to still another embodiment of the present invention. In step S501, a maximum value of the first measurement signal in the variation reference time interval is determined. In step S503, an average value of the detection signal in the variation reference time interval is determined. In step S505, it is determined whether the difference between the maximum value and the average value is smaller than the difference threshold. In step S507, it is determined that the first measurement signal is less than the statistical time of the reference threshold in the variation reference time interval. In step S509, it is determined whether the statistical time is less than a time threshold. In step S511, when it is determined that the difference between the maximum value and the average value is less than the difference threshold, and the judgment statistical time is less than the time threshold, the set measurement range is adjusted to be one of the preset measurement ranges, and the adjusted set measurement is performed. The upper limit of the range is greater than the maximum value. In step S513, when it is determined that the difference between the maximum value and the average value is not less than the difference threshold, and the judgment statistical time is not less than the time threshold, the set measurement range is adjusted to be one of the preset measurement ranges, and the adjustment is performed. The upper limit of the set measurement range is not greater than the maximum value.

In this embodiment, whether to adjust the set measurement range and how to adjust the set measurement range is determined according to the degree of fluctuation of the first measurement signal. Further, when the difference between the maximum value and the average value of the first measurement signal in the variation reference time interval is large, the signal value representing the first measurement signal changes relatively sharply. Conversely, when the difference between the maximum value and the average value of the first measurement signal in the variation reference time interval is small, the signal value representing the first measurement signal is relatively stable. On the other hand, in this embodiment, the time when the first measurement signal is smaller than the reference threshold is further determined, thereby determining the signal value distribution of the first measurement signal simply and effectively.

Therefore, as described in step S511, when it is determined that the difference between the maximum value and the average value is less than the difference threshold, and the judgment statistical time is less than the time threshold, the value of the first measurement signal value changes relatively quickly, but the variation range is not large. . At this time, the set measurement range is one of the preset measurement ranges, and the upper limit of the adjusted set measurement range is greater than the maximum value, thereby avoiding switching the set measurement range too frequently, and there is an error. risks of. Since the range of the first measurement signal is not large, the action can also make the first measurement signal have a fairly good resolution. On the other hand, as described in step S513, when it is determined that the difference between the maximum value and the average value is not less than the difference threshold, and the judgment statistical time is not less than the time threshold, the signal value representing the first measurement signal is relatively stable, but Once the first measurement signal changes, the first measurement signal will vary considerably. At this time, the set measurement range is one of the preset measurement ranges, and the upper limit of the adjusted set measurement range is not greater than the maximum value. Therefore, the first measurement signal has a better resolution for most of the time, and when the signal changes, the control circuit can also adjust the set measurement range according to the second measurement signal as described above, and according to The second measurement signal compensates for the first measurement signal, so that the first measurement signal still retains the correct measurement result.

In summary, the present invention provides a signal measuring device and a signal measuring method. The signal measuring device and the signal measuring method have a set measuring range and a compensation measuring range. The set measurement range is switched to a plurality of preset measurement ranges. Thereby, the signal measuring device and the signal measuring method can measure the signal to be measured by switching the set measuring range to try to measure the range to be measured with the dynamic range closest to the signal to be measured, thereby The measurement results have a better resolution. On the other hand, the compensation measurement range covers all the preset measurement ranges. Therefore, the ideal signal measurement device and signal measurement method can obtain the unclip measurement result according to the compensation measurement range. And the signal measuring device and the signal measuring method can switch the set measurement range to the plurality of preset measurement ranges according to the uncut detection result, so that the set measurement range can be In addition to the dynamic range of the signal to be measured, the measurement result has better resolution.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

1, 1', 1" ‧ ‧ signal measuring device
12‧‧‧Detection circuit
122', 124', 126'‧‧‧ protection circuit
128”‧‧‧Programmable Gain Amplifier
13‧‧‧Communication channel
14‧‧‧First measuring circuit
142‧‧‧First amplifier
144‧‧‧Anti-aliasing filter
146‧‧‧First analog-to-digital converter
16‧‧‧Second measurement circuit
162‧‧‧second amplifier
164‧‧‧Anti-aliasing filter
166‧‧‧Second analog-to-digital converter
18‧‧‧Control circuit
182‧‧‧Digital Signal Processor
184‧‧‧Field programmable gate array
19‧‧‧Coupling circuit
192‧‧‧pulse transformer
194‧‧‧Photocoupler
2‧‧‧Test object
D1~D4‧‧‧ Diode
E1‧‧‧ first detection end
E2‧‧‧Second detection end
E3‧‧‧ external input
ND‧‧‧pressure node
R1‧‧‧first resistance
R2‧‧‧second resistance
R1"~R4"‧‧‧resistance
RL1‧‧‧First Relay
RL2‧‧‧second relay
RL3‧‧‧ third relay
RL4‧‧‧fourth relay

FIG. 1 is a functional block diagram of a signal measuring apparatus according to an embodiment of the invention. 2 is a functional block diagram of a signal measuring device according to another embodiment of the present invention. FIG. 3 is a functional block diagram of a signal measuring apparatus according to still another embodiment of the present invention. FIG. 4 is a flow chart of a method for measuring a signal according to an embodiment of the invention. FIG. 5 is a flowchart of a method for measuring a signal according to another embodiment of the present invention. FIG. 6 is a flow chart of a method for measuring a signal according to a further embodiment of the present invention. FIG. 7 is a flowchart of a method for measuring a signal according to still another embodiment of the present invention. FIG. 8 is a flowchart of a method for measuring a signal according to still another embodiment of the present invention.

Claims (11)

A signal measuring device includes: a detecting circuit for electrically connecting a test object to generate a detecting signal; a first measuring circuit electrically connected to the detecting circuit, the first measuring The circuit generates a first measurement signal according to the detection signal and according to one of the first measurement range and the second measurement range, wherein the second measurement range is greater than the first measurement range; a second measuring circuit electrically connected to the detecting circuit, wherein the second measuring circuit generates a second measuring signal according to the detecting signal and a compensation measuring range, wherein the compensation measuring range is greater than the second measuring a measuring circuit; and a control circuit electrically connected to the first measuring circuit and the second measuring circuit, wherein the control circuit controls the first measuring circuit to switch the first measuring range according to the second measuring signal And one of the second measurement ranges. The signal measuring device of claim 1, wherein the control circuit switches the second measurement range according to the second measurement range when the first measurement circuit switches one of the first measurement range and the second measurement range The signal compensates for the first measurement signal. The signal measuring device of claim 1, wherein the first measuring circuit comprises a first amplifier and a first analog-to-digital converter, the first amplifier is electrically connected to the detecting circuit and the first analog digital a converter, the control circuit adjusts a gain of the first amplifier according to a magnitude of a signal value of the first measurement signal and a signal value of the second measurement signal to switch the first measurement range and the second measurement range One of them. The signal measuring device of claim 3, wherein the second measuring circuit comprises a second amplifier and a second analog-to-digital converter, the second amplifier is electrically connected to the detecting circuit and the second analog digital The converter adjusts the gain of the second amplifier according to the magnitude of the signal value of the first measurement signal and the signal value of the second measurement signal to adjust the compensation measurement range. The signal measuring device of claim 4, wherein the detecting circuit comprises a first detecting end, a second detecting end and a gear shifting sub-circuit, the gear switching sub-circuit comprising: a first a resistor, the two ends are electrically connected to the first detecting end and a voltage dividing node respectively; a second resistor is electrically connected to the second detecting end and the voltage dividing node respectively; a first relay, the first An output end of a relay is electrically connected to an input end of the first amplifier, and the plurality of input ends of the first relay are electrically connected to the first detecting end, the voltage dividing node and an external input end respectively; a relay, the output end of the second relay is electrically connected to another input end of the first amplifier, and the plurality of input ends of the second relay are electrically connected to the second detecting end, the voltage dividing node and the external input a third relay, the output end of the third relay is electrically connected to an input end of the second amplifier, and two of the plurality of input ends of the third relay are electrically connected to the first detecting end and the An external input; and a fourth relay, the The output end of the fourth relay is electrically connected to the other input end of the second amplifier, and two of the plurality of input ends of the fourth relay are electrically connected to the voltage dividing node and the external input end respectively. A signal measurement method includes: electrically connecting a test object to generate a detection signal; generating a first measurement signal according to the detection signal and a set measurement range, wherein the set measurement range is multiple pre-measurements Setting one of the measurement ranges; generating a second measurement signal according to the detection signal and a compensation measurement range, and the upper limit of the compensation measurement range is not less than an upper limit of any of the preset measurement ranges; Whether the signal value of the first measurement signal is greater than the current upper limit of the set measurement range; and when determining that the signal value of the first measurement signal is greater than the current upper limit of the set measurement range, The magnitude of the signal value of the second measurement signal switches the set measurement range to the other of the preset measurement ranges, and the upper limit of the set measurement range after the switching is greater than the signal of the second measurement signal The value size. The method for measuring the signal according to claim 6, further comprising: when the set measurement range is switched to the other of the preset measurement ranges at a first time, the second measurement according to the first time The signal compensates for the first measurement signal of the first time. The signal measurement method of claim 6, wherein the preset measurement ranges include a first measurement range and at least a second measurement range, and an upper limit of the current set measurement range is greater than the first quantity. The upper limit of the measurement range and the upper limit of the at least one second measurement range, the upper limit of the first measurement range is greater than the upper limit of the at least one second measurement range, and the signal measurement method further comprises: obtaining the first measurement signal Determining a valid reference value in the reference time interval; determining whether the valid reference value is less than an upper limit of the first measurement range or less than an upper limit of the at least one second measurement range; and determining that the valid reference value is less than When the upper limit of the first measurement range is less than the upper limit of the at least one second measurement range, the set measurement range is switched to the first measurement range. The signal measurement method of claim 6, further comprising: determining whether the first measurement signal conforms to a signal template in a template reference time; and determining that the first measurement signal meets the template reference time In the signal template, the set measurement range is adjusted to be a first measurement range of the preset measurement ranges; wherein the preset measurement ranges further define at least one second measurement range, The upper limit of the first measurement range is not less than the maximum value of the first measurement signal, and the upper limit of the first measurement range is smaller than the upper limit of the at least one second measurement range. The method for measuring a signal according to claim 6, further comprising: determining a maximum value of the first measurement signal in a variation reference time interval; determining an average value of the detection signal in the variation reference time interval Determining whether the difference between the maximum value and the average value is less than a difference threshold value; determining that the first measurement signal is less than a reference time of a statistical time in the variation reference time interval; determining whether the statistical time is less than one a time threshold; and when it is determined that the difference between the maximum value and the average value is less than the difference threshold value, and determining that the statistical time is less than the time threshold, adjusting the set measurement range to one of the preset measurement ranges The upper limit of the adjusted measurement range is greater than the maximum value. The method for measuring a signal according to claim 6, further comprising: determining a maximum value of the first measurement signal in a variation reference time interval; determining an average value of the detection signal in the variation reference time interval Determining whether the difference between the maximum value and the average value is less than a difference threshold value; determining that the first measurement signal is less than a reference time of a statistical time in the variation reference time interval; determining whether the statistical time is less than one a time threshold; and when it is determined that the difference between the maximum value and the average value is not less than the difference threshold, and determining that the statistical time is not less than the time threshold, adjusting the set measurement range to the preset measurement ranges. In one of the adjustments, the upper limit of the set measurement range is not greater than the maximum value.