CN201515355U - Automatic frequency-selection narrowband bandpass filter - Google Patents
Automatic frequency-selection narrowband bandpass filter Download PDFInfo
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- CN201515355U CN201515355U CN2009200348141U CN200920034814U CN201515355U CN 201515355 U CN201515355 U CN 201515355U CN 2009200348141 U CN2009200348141 U CN 2009200348141U CN 200920034814 U CN200920034814 U CN 200920034814U CN 201515355 U CN201515355 U CN 201515355U
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Abstract
The utility model relates to an automatic frequency-selection narrowband bandpass filter comprising a controller and a bandpass filter, wherein, a resistor connection port RX1 and a resistor connection port RX2 of the controller are connected with the resistor connection port RX1 and the resistor connection port RX2 of the bandpass filter; an internal signal port VXO of the controller is connected with the internal signal port VXO of the bandpass filter; an amplitude signal connection port ADIN of the controller is connected with the amplitude signal connection port ADIN of the bandpass filter; and a test signal input port VXI is formed on the controller. The automatic frequency-selection narrowband bandpass filter can automatically adjust the mid-frequency of the bandpass filter in real-time before testing, thereby reducing the influence on a test result caused by environmental temperature, and overcoming the problem that testing error is increased because the frequencies of test signals and interference signals are approximate, and the mid-frequency of the filter deviates caused by temperature when the general bandpass filter works in a high Q narrowband (ranging from minus 0.5Hz to plus 0.5Hz).
Description
Technical field
The utility model belongs to the power test technical field, particularly the select frequency automatically narrow band filter.
Background technology
In power industry ground network test process, by inject the signal of the certain electric current of a certain frequency to ground network, calculate the earth mat impedance with recording earth mat zero potential voltage and current again, can get by the earth mat impedance under the test different frequency when measuring the earth mat frequency characteristic, because the interference of on-the-spot power frequency component, frequency test signal (40Hz---60Hz) is near power frequency in addition, and the removal of interference is the key that obtains reliable test result.At present, the method that actual filtering interfering adopts, adopt low pass filter just can satisfy for High-frequency Interference, and for test signal and close interference signal, must with high Q value arrowband (± 0.5Hz) band pass filter, when band pass filter Q value during very big and smaller bandwidth, determine the electric capacity of this filter center frequency and resistance owing to the temperature influence change greatly, cause the filter center frequency easily to be offset, the test result that obtains is inaccurate.To near the interference the frequency test signal, adopt the high Q value arrowband adjust centre frequency in advance (± 0.5Hz) band pass filter carries out interference filtering, when the test environment temperature with adjust high Q value arrowband (± 0.5Hz) during the band pass filter centre frequency ambient temperature not simultaneously, the increase of test result deviation.
The utility model content
The purpose of this utility model be for overcome test signal and interference signal frequency near and the generalized ribbon bandpass filter in high Q value arrowband (± 0.5Hz) increase of time work filter center frequency temperature influence skew ambassador test error problem and a kind of select frequency automatically narrow band filter is provided.
The purpose of this utility model realizes in the following manner: a kind of select frequency automatically narrow band filter, comprise controller (1) and band pass filter (2), controller (1) is provided with resistance connectivity port (RX1, RX2), internal signal connectivity port (VXO), amplitude signal connectivity port (ADIN) and test signal input port (VXI), band pass filter (2) is provided with resistance connectivity port (RX1, RX2), internal signal connectivity port (VXO) and amplitude signal connectivity port (ADIN), resistance connectivity port (the RX1 of controller (1), RX2) with the resistance connectivity port (RX1 of band pass filter (2), RX2) connect, the internal signal port (VXO) of controller (1) is connected with the internal signal port (VXO) of band pass filter (2), and the amplitude signal connectivity port (ADIN) of controller (1) is connected with the amplitude signal connectivity port (ADIN) of band pass filter (2).
Described controller (1) comprises CPU element (11), adjustable resistance unit (12), push-button unit (13), LCD display unit (14), reference frequency generation unit (15), switch element (16) and amplitude sampling unit (17), push-button unit (13) is connected with CPU element (11) respectively with amplitude sampling unit (17), CPU element (11) respectively with adjustable resistance unit (12), LCD display unit (14), reference frequency generation unit (15) is connected with switch element (16), reference frequency generation unit (15) is connected with switch element (16), adjustable resistance unit (12) and resistance connectivity port (RX1, RX2) connect, amplitude signal connectivity port (ADIN) is connected with amplitude sampling unit (17), switch element (16) is connected with internal signal port (VXO), and test signal input port (VXI) is connected with switch element (16).
The utility model overcome test signal and interference signal frequency near and the generalized ribbon bandpass filter in high Q value arrowband (± skew of work filter center frequency temperature influence makes the problem of test error increase 0.5Hz) time.Can before test, adjust the centre frequency of band pass filter automatically in real time, thereby reduced the influence of ambient temperature to test result, differ by more than 1Hz according to test data for interference signal frequency and frequency test signal, filtering output and given frequency-selecting signal amplitude error are less than 1%, solved the influence of temperature, satisfied instructions for use test.
Description of drawings
Fig. 1 is the utility model connection diagram.
Fig. 2 is the band pass filter circuit schematic diagram.
Fig. 3 is the controller principle block diagram.
Fig. 4 is the controller circuitry schematic diagram.
Embodiment
As shown in Figure 1, the utility model is made of controller 1 and high Q value narrow band filter 2 two parts, controller 1 is provided with resistance connectivity port RX1, RX2, internal signal port VXO, amplitude signal connectivity port ADIN and test signal input port VXI, band pass filter 2 is provided with resistance connectivity port RX1, RX2, internal signal port VXO and amplitude signal connectivity port ADIN, the resistance connectivity port RX1 of controller 1, RX2 respectively with the resistance connectivity port RX1 of band pass filter 2, RX2 connects, the centre frequency of band pass filter 2 was also along with change when controller 1 output resistance changed, the internal signal port VXO of controller 1 is output test signal or standard signal port, the internal signal port VXO of controller 1 is connected with the internal signal port VXO of band pass filter 2, the amplitude signal connectivity port ADIN of controller 1 is connected with the amplitude signal connectivity port ADIN of band pass filter, and the amplitude signal connectivity port ADIN of controller 1 is the input that controller 1 detects band pass filter 2 output amplitudes.
As shown in Figure 2, high Q value narrow band filter 2 is formed the primary filter circuit by amplifier U1, U2, U3, U4, U5, capacitor C 1, C2, C3, resistance R 1, R2, R3, R4, R5, R6, R7, D8, R9, R10, R12 and diode D1, wherein resistance R 9 and R10 are by resistance connectivity port RX1 and RX2 outer meeting resistance, the outer meeting resistance value determines the centre frequency of this band pass filter, resistance R 1 is connected with internal signal port VXO, and amplifier U4 output is connected with amplitude signal connectivity port ADIN with capacitor C 3 through diode D1.
As shown in Figure 3, controller 1 comprises CPU element 11, adjustable resistance unit 12, push-button unit 13, LCD display unit 14, reference frequency generation unit 15, switch element 16 and amplitude sampling unit 17, push-button unit 13 is connected with CPU element 11 respectively with amplitude sampling unit 17, CPU element 11 respectively with adjustable resistance unit 12, LCD display unit 14, reference frequency generation unit 15 is connected with switch element 16, reference frequency generation unit 15 is connected with switch element 16, adjustable resistance unit 12 and resistance connectivity port RX1, RX2 connects, amplitude signal connectivity port ADIN is connected with amplitude sampling unit 17, switch element 16 is connected with internal signal port VXO, and test signal input port VXI is connected with switch element 16.Adjustable resistance unit 12 is exported variable resistor by CPU element 11 controls from resistance connectivity port RX1, RX2, push-button unit 13 is set the frequency of the signal that needs test by button S1 and S2, LCD display unit 14 shows test results, reference frequency generation unit 15 is controlled to be the centre frequency of adjusting band pass filter 2 provides standard signal from set fixed-frequency amplitude to band pass filter 2 by CPU element 11, switch element 16 is used for switching standards signal and test signal, and amplitude sampling unit 17 is used for the output amplitude of sample strip bandpass filter 2.
As shown in Figure 4, CPU element 11 is made of module U1, adjustable resistance unit 12 is made of digital regulation resistance U2 and U3, push-button unit 13 is made up of button S1 and S2, amplitude sampling unit 17 is made of reference frequency module U4 and AD modular converter U5, reference frequency generation unit 15 is made of resistance R 7, R8, R9, R10, operational amplifier U6, frequency divider U7, U8, switch element 16 is made of relay J DQ1, JDQ2, triode Q1, Q2, resistance R 5, R6, and the LCD display unit is made of modular LCD.40,39,38,37,36,35,34,33 pin of module U1 draw on power supply through the RP1 exclusion, be connected with 11,12,13,14,15,16,17,18 pin of modular LCD respectively, 14,15,16,6,7 pin of module U1 are connected with 10,8,7,6,5 pin of modular LCD respectively.29,28,23 of module U1 is connected with 2,5,1 pin of digital regulation resistance U2 and U3 respectively, 3 pin of module U1 are connected with 7 pin of digital regulation resistance U2,5 pin of module U1 are connected with 7 pin of digital regulation resistance U3,3 pin of digital regulation resistance U2 are connected with 6 pin of digital regulation resistance U3,6 pin of digital regulation resistance U2 are connected with resistance connectivity port RX2, and 6 pin of digital regulation resistance U3 are connected with resistance connectivity port RX1.17,18,19,20,21 of module U1 is connected with 19,18,17,16,15 pin of AD modular converter U5 respectively, 1 pin of AD modular converter U5 is connected with amplitude signal connectivity port ADIN, and 14 pin of AD modular converter U5 are connected with 6 pin of reference frequency module U4.22,8 pin of module U1 draw on power supply through resistance R 3, R4, are connected with the end of button S1, S2 respectively, and the other end of button S1, S2 is connected with power supply ground.4 pin of module U1 are connected with 14 pin of frequency divider U7,12 pin of frequency divider U7 are connected with 14 pin of frequency divider U8,12 pin of frequency divider U8 are connected with 3 pin of operational amplifier U6, one end of resistance R 7 is connected with power supply ground, the other end of resistance R 7 is connected with resistance R 8, be connected with 2 pin of operational amplifier U6 simultaneously, the other end of resistance R 8 is connected with power supply, 1 pin of operational amplifier U6 is connected with resistance R 9 one ends, the other end of resistance R 9 is connected with an end of resistance R 10, the other end of resistance R 9 is connected with the contact 1 of relay J DQ2 simultaneously, and the other end of resistance R 10 is connected with power supply ground.The contact 1 of relay J DQ1 is connected with test signal port VXI, the contact 2 of relay J DQ1 be connected with internal signal port VXO again after the contact 2 of relay J DQ2 is connected.
Concrete operation principle process of the present utility model is:
During test, the CPU element 11 of first step controller 1 is according to button S1, the frequency of the measured signal that S2 is provided with, it is consistent with the measured signal of test signal input port VXI input to make reference frequency generation unit 15 produce frequency, amplitude is the standard signal of Vb is delivered to band pass filter 2 by the internal signal port VXO of controller 1 internal signal port VXO, after the CPU element 11 of the second step controller 1 makes resistance connectivity port RX1 and RX2 export a resistance value, whether the output amplitude that detects the amplitude signal connectivity port ADIN of band pass filter 2 is maximum, as not being maximum, change the adjustable electric resistance, whether detect band pass filter 2 output amplitudes once more is maximum, repeat this process and be maximum up to band pass filter 2 output amplitudes, and the note maximum is Vmax, the 3rd step controller 1 makes the test signal of test signal input port VXI input deliver to the internal signal port VXO of band pass filter 2 through internal signal port VXO, recording the band pass filter output amplitude is Vo, selected signal amplitude is Vb*Vo/Vmax in the calculating measured signal of the 4th step, shows on LCD display at last.
Test result of the present utility model is as follows:
Test data
| Given measured signal | Require the signal of frequency-selecting | Standard signal Vb | Standard signal frequency-selecting amplitude Vmax | Measured signal frequency-selecting amplitude Vo | Measured signal test value (calculating) |
| 2V peak value 50% duty ratio 40Hz square wave | Given square wave fundamental voltage amplitude | 2V peak value 50% duty ratio 40Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 2.546V | 2.546V |
| Given measured signal | Require the signal of frequency-selecting | Standard signal Vb | Standard signal frequency-selecting amplitude Vmax | Measured signal frequency-selecting amplitude Vo | Measured signal test value (calculating) |
| 1V peak value 50% duty ratio 40Hz square wave | Given square wave fundamental voltage amplitude | 2V peak value 50% duty ratio 40Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 1.273V | 1.273V |
| 2V peak value 50% duty ratio 60Hz square wave | Given square wave fundamental voltage amplitude | 2V peak value 50% duty ratio 60Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 2.546V | 2.546V |
| 1V peak value 50% duty ratio 60Hz square wave | Given square wave fundamental voltage amplitude | 2V peak value 50% duty ratio 60Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 1.273V | 1.273V |
| 2V peak value 40Hz sine wave | Given sinusoidal wave amplitude | 2V peak value 50% duty ratio 40Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 2.001V | 2.001V |
| 2V peak value 60Hz sine wave | Given sinusoidal wave amplitude | 2V peak value 50% duty ratio 60Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 1.998V | 1.998V |
| Sinusoidal wave and the 2V peak value 41Hz sine-wave superimposed of 2V peak value 40Hz | The sinusoidal wave amplitude of 40Hz | 2V peak value 50% duty ratio 40Hz square wave fundamental voltage amplitude 2.546V | 2.546V | 1.997V | 1.997V |
Conclusion: differ by more than 1Hz according to test data for interference signal frequency and frequency test signal, filtering output and given frequency-selecting signal amplitude error have solved the influence of temperature to test less than 1%, satisfy instructions for use.
Claims (2)
1. select frequency automatically narrow band filter, comprise controller (1) and band pass filter (2), it is characterized in that: controller (1) is provided with resistance connectivity port (RX1, RX2), internal signal port (VXO), amplitude signal connectivity port (ADIN) and test signal input port (VXI), band pass filter (2) is provided with resistance connectivity port (RX1, RX2), internal signal port (VXO) and amplitude signal connectivity port (ADIN), resistance connectivity port (the RX1 of controller (1), RX2) with the resistance connectivity port (RX1 of band pass filter (2), RX2) connect, the internal signal port (VXO) of controller (1) is connected with the internal signal port (VXO) of band pass filter (2), and the amplitude signal connectivity port (ADIN) of controller (1) is connected with the amplitude signal connectivity port (ADIN) of band pass filter (2).
2. a kind of select frequency automatically narrow band filter as claimed in claim 1, it is characterized in that: described controller (1) comprises CPU element (11), adjustable resistance unit (12), push-button unit (13), LCD display unit (14), reference frequency generation unit (15), switch element (16) and amplitude sampling unit (17), push-button unit (13) is connected with CPU element (11) respectively with amplitude sampling unit (17), CPU element (11) respectively with adjustable resistance unit (12), LCD display unit (14), reference frequency generation unit (15) is connected with switch element (16), reference frequency generation unit (15) is connected with switch element (16), adjustable resistance unit (12) and resistance connectivity port (RX1, RX2) connect, amplitude signal connectivity port (ADIN) is connected with amplitude sampling unit (17), switch element (16) is connected with internal signal port (VXO), and test signal input port (VXI) is connected with switch element (16).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200348141U CN201515355U (en) | 2009-09-29 | 2009-09-29 | Automatic frequency-selection narrowband bandpass filter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2009200348141U CN201515355U (en) | 2009-09-29 | 2009-09-29 | Automatic frequency-selection narrowband bandpass filter |
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| CN201515355U true CN201515355U (en) | 2010-06-23 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2009200348141U Expired - Fee Related CN201515355U (en) | 2009-09-29 | 2009-09-29 | Automatic frequency-selection narrowband bandpass filter |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107765138A (en) * | 2016-08-23 | 2018-03-06 | 丰郅(上海)新能源科技有限公司 | A kind of grid monitoring system |
| CN107843807A (en) * | 2016-09-20 | 2018-03-27 | 丰郅(上海)新能源科技有限公司 | A kind of moment in Voltage Drop can turn off the monitoring system of power network in time |
| CN110611519A (en) * | 2019-08-28 | 2019-12-24 | 深圳市普威技术有限公司 | Wave trap |
| CN112104329A (en) * | 2020-09-22 | 2020-12-18 | 唐有钢 | Thing networking data security signal calibration system |
-
2009
- 2009-09-29 CN CN2009200348141U patent/CN201515355U/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107765138A (en) * | 2016-08-23 | 2018-03-06 | 丰郅(上海)新能源科技有限公司 | A kind of grid monitoring system |
| CN107765138B (en) * | 2016-08-23 | 2021-05-14 | 丰郅(上海)新能源科技有限公司 | Power grid monitoring system |
| CN107843807A (en) * | 2016-09-20 | 2018-03-27 | 丰郅(上海)新能源科技有限公司 | A kind of moment in Voltage Drop can turn off the monitoring system of power network in time |
| CN110611519A (en) * | 2019-08-28 | 2019-12-24 | 深圳市普威技术有限公司 | Wave trap |
| CN112104329A (en) * | 2020-09-22 | 2020-12-18 | 唐有钢 | Thing networking data security signal calibration system |
| CN112104329B (en) * | 2020-09-22 | 2021-03-30 | 山东维平信息安全测评技术有限公司 | Thing networking data security signal calibration system |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20100623 Termination date: 20160929 |