CN2139331Y - Multifunctional intelligent tester for telephone noise - Google Patents

Abstract

A multifunctional intelligent tester for telephone noise is a tester for telephone noise controlled by a microcomputer. It can realize the automatic upshifting, automatic measurement and data processing of the multiple parameter detection, and realize the automatic fault detection and automatic level adjustment. It is composed of a microcomputer, an interface circuit, an analogue-to-digital converter, a controller, a display, a barrier housing, a fan-in network, an attenuator, an amplifier, an electric filter, an analog switch and a root-mean-square quantity converter. It is provided with an excess voltage double protector and an oscillator for self testing and self proofreading. It has the advantages of intelligence, multifunction, high performance and low cost, and it can also be used for the distortion measurement of a carrier equipment.

Description

Multifunctional intelligent tester for telephone noise

The utility model is the microcomputer-controlled intelligent phone noise detector of a kind of usefulness, belongs to the communication instrument field of instrumentation technology.

Present existing phone noise detector majority is the manual instrument of function singleness, inconvenient operation, technological obsolescence.

The purpose of this utility model is at the deficiencies in the prior art, and a kind of intelligent multi-function phone noise detector is provided, and it can realize the automatic detection of a plurality of parameters.

The utility model adopts microcomputer control, realizes the fluid drive of a plurality of parameter detecting, measures and data processing automatically, realizes that automatic fault detects, automatic electric-level is proofreaied and correct.The utility model is by microcomputer, phone noise checkout gear, interface circuit, modulus (A/D) transducer, controller, display and screening housing are formed, phone noise checkout gear is made of fan-in network, attenuator, amplifier, filter, analog switch and root-mean-square value transducer, and is subjected to computer control.In order to detect automatically and to rectify an instrument, be provided with the oscillator that a self check self-correcting is used in the phone noise checkout gear.In order to improve accuracy of detection, filter adopts the high-performance active filter, and under system controlled by computer, as long as increase a special filter, instrument just can be used for the distortion measurement of carrier terminal equipment.In order to improve the reliability of instrument, all be connected to voltage-stabiliser tube on the former and deputy coil of the transformer of input unit both sides, make instrument have dual overvoltage protection performance.The ground wire of the single-ended input signal cable of A/D converter (holding wire 1) adopts special-purpose ground wire, to significantly reduce the interference of digital circuit to analogue measurement.

The utility model compared with prior art has advantages such as intellectuality, multi-functional, high-performance and low cost.It not only can be used to measure the phone noise, also can be used for the carrier terminal equipment distortion measurement.

Fig. 1 is the utility model structure block diagram; Fig. 2 is a phone noise checkout gear block diagram; Fig. 3 is the fan-in network circuit theory diagrams; Fig. 4 is controller and interface circuit schematic diagram thereof; Fig. 5 is input, output interface circuit schematic diagram.

The utility model can take scheme shown in the drawings to realize.Phone noise checkout gear (A) among Fig. 1 can be realized by scheme shown in Figure 2; A/D converter (B) becomes digital signal to analog signal conversion, can adopt 12 integral a/d converters 7109, and can directly be connected with microcomputer; Microcomputer (C) can adopt 8 single-chip microcomputers 8031, (K) is keyboard; Low order address latch (D) can adopt integrated package 74LS373; Read-only memory (E) is used to deposit computer software, and it can adopt 2764; The serial/parallel line output register of state control signal (F) (is IC among Fig. 4 ₁₁) serial signal of microcomputer output become parallel signal keep in, offer phone noise checkout gear (A), can adopt 74LS164 to form, similarly the serial/parallel line output register of gear control signal (G) (be IC21 among Fig. 4, R ₂₀, R ₂₁Be exclusion) also can adopt 74LS164 to form; Control gate (H) (being IC31 and IC41 among Fig. 4) is under system controlled by computer, microcomputer output signal on the serial input-output line is delivered to (F), (G) and display (I) respectively, delivering to microcomputer by the signal of keyboard (K) input, also play the signal damping effect simultaneously, it can be made of two 74LS126.Display (I) is made up of three parts, and the one, the measurement result display part, two LED luminous tubes that overflowed up and down by a LED symbol charactron (can show positive and negative number and numeral 1), demonstration (are RD among Fig. 5 ₁, RD ₁The current-limiting resistance that has comprised LED, RD ₂～RD ₇Also be like this) and three LED charactron (RD among Fig. 5 ₂, RD ₃And RD ₄) constitute, by the IC among four 74LS164(Fig. 5 ₂₂, IC ₃₂, IC ₄₂And IC ₅₂) serial shows signal that microcomputer is sent here becomes parallel drive display device; The 2nd, measurement unit shows, constitutes (the RD among Fig. 5 by seven LED ₇), drive (the IC among Fig. 5 by a 74LS164 ₈₂), indicate respectively dB, V, mv, μ v and %, ‰,

Deng; The 3rd, measurement project and state show, constitute (the RD among Fig. 5 by 12 LED ₅And RD ₆), drive (IC among Fig. 5 by two 74LS164 ₆₂And IC ₇₂), indicate the uneven input of 600 Ω balances, 20K balance, 100K, 200ms(single respectively), 1s(16 time average), 10s(128 time on average), phone weighting, audio frequency, telephone channel, distortion, noise compensation and self check self-correcting etc.Keyboard (K) is by six button (K among Fig. 5 ₁～K ₆) and a parallel/serial shift register (as 74LS165) (IC among Fig. 5 ₁₂) and exclusion (R among Fig. 5 ₂₂) form, (whenever pressing primary key can selective sequential 600 Ω balance to comprise the input mode options button, the 20K balance, a kind of in the uneven three kinds of input modes of 100K, the mode of choosing is indicated by LED), noise compensation key, self check self-correcting key, measurement project options button (but is whenever pressed the weighting of primary key selective sequential phone, audio level, a kind of in four of telephone channel and the distortions, the project of choosing is indicated by LED), metering system (time) key (but is whenever pressed primary key selective sequential single (200ms), 16 times average (1s), a kind of in 128 average (10s) three kinds of modes, the mode of choosing is indicated by LED), display mode key (can in dB and voltage system alternate selection).Label A among Fig. 5 ₂, B ₂, C ₂, D ₂, E ₂, F ₂, G ₂Respectively with Fig. 4 in corresponding label connect together.Line 1 among Fig. 1 transmits the direct voltage of the measured root-mean-square value of representative; No. 2 lines are the interrupt request singal line; No. 3 lines are the control signal wire of single-chip microcomputer to A/D converter; No. 4 lines are A/D converter OPADD line; 8 position datawires of No. 5 line A/D converter outputs; The data port bus that No. 6 lines are single-chip microcomputer; No. 7 lines are the address latch line; No. 8, No. 9 and No. 10 line are address bus; No. 11 lines are the read-only memory output data bus; No. 12 lines are the serial input-output line; No. 13, No. 17, No. 19, No. 21, No. 23 lines are serial synchronised clock line; No. 14 lines are the control bus of serial line interface; No. 15 lines are the State Control bus; No. 16 lines are the gear control bus; No. 18, No. 20, No. 22 lines are the serial output line after cushioning; No. 24 lines are the serial incoming line.

Fig. 2 is the implementation figure of phone noise checkout gear, and fan-in network (A1) can adopt circuit shown in Figure 3.Analog switch (F ₁) can adopt analog switching circuit 4051, it can select different filters under the state control signal effect, carry out the measurement of disparity items; When self check, also can select to lead directly to, promptly need not any filter.Phone weighting filter (G ₁) employing high-performance phone weighting active filter, speech path channel filter (H ₁) be the active band-pass filter of 0.3～3.4KHz.Tone filter (I1) adopts the active band-pass filter of 31.5HZ～16KHZ.More than three filters all meet ccitt standard.Harmonic filter (J1) adopts the high-performance active filter, and it is to 400HZ(or 800HZ) relative attenuation reaches-more than the 92dB, to 800HZ(or 1.6KHZ) more than then straight-through, ripple is ± 0.1dB, more than four filter nominal gains be 30dB.As long as increase a high-performance harmonic active filter, can constitute carrier terminal equipment harmonic distortion instrument.Preamplifier (C1) can adopt low noise operational amplifier 0p07, and gain can be 12dB.Variolosser (B1) and (D1) constitute by analog switch (as 4051) and precision resistance network, under the control signal effect, (B1) can to analog signal decay respectively 0dB ,-20dB ,-40dB, also can import-the 800HZ self-test signal of 52dB; (D1) can to simulation (tested) signal decay respectively 0dB ,-10dB ,-20dB or-30dB, also can import-30dB or-the 800HZ self-test signal of 60dB.Variable amplifier (E1) can adopt universal amplifier (as LM351) to constitute, and gain can be 10dB or 20dB under the control signal effect.Main amplifier (L1) can adopt universal amplifier (as half of LM353), and gaining is 10dB.Electric pressure converter (M1) can adopt AD636 to constitute, and it is transformed into direct voltage with the effective value of AC signal.(N1) for the measured signal output buffer amplifier, can constitute by general amplifier (as half of LM353), gaining is 10dB.(O1) test oneself for self check and use oscillator, oscillator frequency is 800HZ, and output is about-20dB, and it only connects test signal by state control signal when self check.By (O1) computer and variolosser (B1) and (D1), analog switch (F1) and (K1) can constitute automatic fault and detect and the level correction device.Part among the 1a and 2a, 3a, 4a are the gear control line, by No. 16 line inputs among Fig. 1; Another part among the 1a and 5a, 6a, 7a are the State Control line, by No. 15 line inputs among Fig. 1.Fan-in network among Fig. 2 (A1) as shown in Figure 3, it can switch three kinds of input modes (a, b and Shang) (600 Ω balances, 20K balance, 100K imbalance) under the control of state control signal, it can also be under gear control signal control to the decay of signal work-20dB or do not decay.On the former and deputy coil of balance variable device T, be connected to voltage-stabiliser tube D respectively ₁, D ₂, they and resistance R ₈, R ₉Constitute overvoltage protection device, overvoltage is had double protection.Control signal is by filtering, so that reduce the interference of digital circuit to analog channel.The fan-in network main body is by balance variable device T, relay J ₁～J ₅(the figure repeat circuit is in 20K balance input state), precision resistance R ₁～R ₉, capacitor C ₁～C ₃, voltage-stabiliser tube D ₁And D ₂(available 2DW ₇) constitute, all the other are relay drive circuit.IC ₁～IC ₅Can adopt two LM324 four high guaily unit circuit, D ₃～D ₁₂Can adopt the diode of 2CP series, R ₁₀～R ₁₉Be metalfilmresistor, C ₄～C ₈Be filter capacitor, SC ₁, SC ₂Be state control signal, RC ₁For one of gear control signal ， Shang is the analogue ground symbol,

Be the digital grounding symbol.

The utility model can adopt following installation and shielding mode: the B among Fig. 1, C, D, E, F, G and H are installed in the printed board, and account for a shielding storehouse; I and K are mounted to a printed board separately, and close account for one the shielding storehouse.The relay drive circuit of A1 is installed a printed board and is accounted for a shielding storehouse among Fig. 2, and network principal is installed a printed board and account for a shielding storehouse, and transformer accounts for a shielding storehouse; B1, C1, D1, E1 and F1 install a printed board, and respectively account for a shielding storehouse; G1, H1, I1, J1 install a printed board separately, and close account for one the shielding storehouse; K1, L1, M1, N1 and O1 install a printed board, and account for a shielding storehouse.Power transformer accounts for a shielding storehouse; Stabilized voltage power supply accounts for a shielding storehouse.

The high-performance active filter that the utility model adopted is a high performance tape active filter at zero point, it is made up of two operational amplifiers, resistance and electric capacity, between the in-phase input end of an operational amplifier and ground, be connected to the zero return device, between the output of two operational amplifiers and inverting input, be connected to elimination from excitation device.The zero return device is made of a resistor, eliminates from excitation device to be made of the capacitor that two capacity accurately equate.

Claims (5)

1, the microcomputer-controlled intelligent multi-function phone of a kind of usefulness noise detector is characterized in that being made up of microcomputer, phone noise checkout gear, interface circuit, modulus (A/D) transducer, controller, display and screening housing; Phone noise checkout gear is connected with microcomputer by interface circuit, modulus (A/D) transducer, and controller is connected with microcomputer, register and display respectively, and register is connected with phone noise checkout gear.

2, intelligent multi-function phone noise detector according to claim 1, it is characterized in that phone noise checkout gear is made of fan-in network, attenuator, amplifier, filter, analog switch and root-mean-square value transducer, and be connected with computer, wherein phone weighting filter (G1) adopts high-performance phone weighting active filter.

3, intelligent multi-function phone noise detector according to claim 1 and 2 is characterized in that automatic fault detects and the level correction device adopts self check self-correcting oscillator (O ₁), computer and variolosser (B ₁) and (D ₁), analog switch (F ₁) and (K ₁) constitute.

4, intelligent multi-function phone noise detector according to claim 1 and 2 is characterized in that fan-in network is by integrated circuit (IC) ₁～IC ₅, balance variable device T, relay J ₁～J ₅, resistance R ₁～R ₁₉, capacitor C ₁～C ₈, diode D ₁～D ₂Constitute.

5, intelligent multi-function phone noise detector according to claim 4 is characterized in that overvoltage protection device is by the voltage-stabiliser tube D on the former and deputy coil of balance variable device T ₁, D ₂And resistance R ₈, R ₉Constitute.

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