39results about How to "Frequency response width" patented technology

The invention discloses a method of testing mechanical properties of coal in coal-rock composite under dynamic loading and combined static and dynamic loading. An existing coal-rock composite test piece is used; starting from rock less prone to crushing, an SHPB (split Hopkinson pressure bar) test device is used, coal-rock composite loading test is performed by means of attaching a strain gauge, stress of coal is acquired according to stress at each end face of the coal test piece, and stress variation of the coal in the coal-rock composite under dynamic loading. Mechanical properties of coal in a certain surrounding rock environment are acquired, better guidance can be provided for field engineering practice, and the method has major guiding significance for disclosing true failure mechanism of engineering coal.

The invention relates to a device for testing kinetic energy of a spraying water drop. The device comprises a sensor water receiving module, a signal conditioning module, a data collection module, a computer and a data analysis module, wherein the data analysis module is arranged inside the computer, the sensor water receiving module comprises a substrate, an array sensor which is composed of a plurality of piezoelectric membranes is arranged on the substrate, the sensor water receiving module us arranged below spraying water, a sensor outputs a sensed electric charge quantity Q through a forward electrode output end of the sensor after the sensor senses the water drop, a reverse electrode output end of the sensor is grounded, the signal conditioning module comprises an impedance conversion unit and an amplification unit, the impedance conversion unit is used for converting the electric charge quantity Q sensed by the sensor into a voltage quantity U<0> for output, the amplification unit is used for amplifying the voltage quantity U<0> output by the impedance conversion unit and outputting a voltage quantity U<out>, and the data collection module obtains the voltage signal U<out> output by the amplification unit in real time and inputs the voltage signal U<out> into the computer after analog-to-digital (A/D) conversion. The device is widely applicable to kinetic energy tests of spraying water drops in little sprinkling irrigation projects.

The invention relates to a true-root-mean-square capacitive current tester. After a power supply is plugged into a power socket, the power socket transmits power energy to a low-voltage side coil of a test transformer through a main power switch and a test switch, a high-voltage end on a high-voltage side of the test transformer is connected with a high-voltage test cable and is connected in parallel with a serial circuit composed of voltage dividing resistors R1 and R2, a low-voltage end on the high-voltage side of the test transformer is connected with the input end of a current sensor, and a node between the voltage dividing resistors R1 and R2 is connected with the input end of a voltage sensor. The input end of a switching power supply is connected with the output of the main power switch, the output of the switching power supply respectively powers a single chip microcomputer, the current sensor and the voltage sensor, the output ends of the current sensor and the voltage sensor are respectively connected with a signal acquisition end of the single chip microcomputer, and the output of the single chip microcomputer is respectively connected with a voltage display meter, a voltage display meter and a capacitive current display meter. True root mean square measurement on voltage and current is carried out by the sensors, data processing is carried out by the single chip microcomputer, and the true-root-mean-square capacitive current tester has the advantage of high precision, high isolation, broad frequency response and low drift.

The invention relates to an on-line monitoring device for the vibration of the stator winding end of a turbogenerator set and a method for using it, and is characterized in that it is composed of an insulating box (1) and an acceleration sensor (2) arranged in the insulating box (1), and the insulating box (1) Made of epoxy resin, the insulating box (1) is provided with a cylindrical cavity, the acceleration sensor (2) is placed in the cavity, and a metal shielding layer (3) is arranged on the acceleration sensor (2). The epoxy resin cures the sensor (2) and the shielding layer (3) into a whole; the outer side of the insulating box (1) is provided with a groove (4), and the signal output end of the acceleration sensor (2) leads out of the insulating box through a shielded cable (1) outside; the insulating box (1) with the acceleration sensor (2) is bound to the wire rod nose end of the measured stator winding through the groove (4), the acceleration sensor (2) detects the vibration of the stator winding, and The vibration signal is converted into an electrical signal and transmitted to the peripheral detection equipment through the shielded cable.

The embodiment of the invention discloses a soil pressure sensor. The soil pressure sensor comprises a shell, a diaphragm, a PVDF piezoelectric film and an output wire, wherein the shell is of a cavity structure with an opening in the top, the diaphragm covers the opening, the shell is filled with filling liquid, the PVDF piezoelectric film is arranged in the shell and suspended in the filling liquid, one end of the output wire is connected to the PVDF piezoelectric film, and the other end of the output wire extends out of the shell. The soil pressure sensor is wider in application range and high in detection precision.

The invention provides a skull conduction device composed of vibration transducer using HTD as main body and audio frequency phase shift booster amplifier adapter circuit matched therewith. The audio frequency phase shift circuit, power amplification circuit, booster matching circuit and vibration transducer are serially connected; the audio frequency phase shift circuit is inputted by audio frequency electrical signal at input end; the output end of boost matching circuit connects with vibration transducer. The vibration transducer comprises a HTD with a central hole; copper substrate 3 serving as anode of the transducer, silver plating layer 4 serving as cathode of the transducer separately connects with two output end of boosting transformer at two sides of piezoelectric material 2 of HTD. Nylon bolt 5 passes nylon gasket 6, HTD and fastens with nut 8. The fastened HTD outer layer is wrapped and sealed by silica gel 7, thereby reducing sound leakage and possessing relatively better water-proof and anti-impact performance.

The invention discloses a frequency modulation anti-interference hidden earphone system which is used for being connected with an interphone so as to obtain an audio signal and conducting FM on the audio signal. The frequency modulation anti-interference hidden earphone system comprises an adapter and earphones. The adapter comprises an interface module, a power module, an audio quality detection module, a gain control module, an FM module and a signal amplification module. The interface module is connected with the interphone, the audio quality detection module and the gain control module. The gain control module, the FM module and the signal amplification module are connected in sequence. The signal amplification module is connected with the earphones wirelessly. According to the frequency modulation anti-interference hidden earphone system, after FM is conducted on the audio signal, the audio signal is transmitted to the earphones, demodulated through the earphones, processed through a DSP and then played. Compared with existing AM, FM has the advantages of being smaller in distortion, wide in frequency response, high in signal-to-noise ratio, high in amplification efficiency, better in noise resistant effect and capable of improving the tone quality. The audio signal is stabilized through the gain control module so that the communication quality can be improved.

The invention discloses a foam material or soft material dynamic performance measurement method, for the foam material or soft material dynamic performance measurement. First, divide the transmission pole of the Hepuxinsen strut into two sections, and then take a thickness of 10-60 mum piezoelectric film, and affix the micron-level insulation membrane on its both sides, and then paste the piezoelectric film with insulation membrane sandwiched between two transmission poles, and the section of the transmission pole near the specimen is equipped with a one-way limiter in the center, and the one-way limiter is fastened with the transmission pole by the clip fixture; put another section of the transmission pole close to fixed stationary energy absorber through the rubber pad, and the rubber pad modulates the pre-tension through the piezoelectric film; electrical connect the piezoelectric film output electrode and the impedance converter; add sample loading, and through the output of impedance converter to obtain foam material or soft material dynamic force or stress force value. The invention uses the piezoelectric film, making dynamic performance measurement of foam or soft material simple and easy, and with high measurement sensitivity.

The invention discloses a low-energy-consumption high-pollution-resistance ultrahigh-frequency-response digital hydraulic servo control system and a control method. The system comprises digital hydraulic switch valves, a hydraulic cylinder, a displacement sensor, pressure sensors and a digital controller, main pressure oil is respectively connected with main pressure oil ports of a first digital hydraulic switch valve and a second digital hydraulic switch valve, main return oil is respectively connected with secondary pressure oil ports of a third digital hydraulic switch valve and a fourth digital hydraulic switch valve, a secondary pressure oil port of the first digital hydraulic switch valve and a main pressure oil port of the third digital hydraulic switch valve are respectively connected with a hydraulic cylinder piston cavity oil port, a secondary pressure oil port of the second digital hydraulic switch valve and a main pressure oil port of the fourth digital hydraulic switch valve are respectively connected with a hydraulic cylinder rod cavity oil port, the displacement sensor, a first pressure sensor and a second pressure sensor are respectively connected with a comparator, and a signal generator is respectively connected with magnet exciting coils of the four digital hydraulic switch valves. According to the system, ultrahigh-frequency fluid pulse signals are directly converted, and therefore accurate control of hydraulic servo is realized.

The invention relates to the technical field of loudspeaker box manufacture, in particular to a planar loudspeaker comprising a soundboard, an annular conducting coil, a soft magnet, a voice coil, a bias coil, a slide resistor Rw, a resistor R1, a super-audio oscillation circuit and a power amplification circuit. The annular conducting coil is disposed on the soundboard, the soft magnet is provided with an opening, the sound board is disposed at the opening, the soft magnet is wound with the voice coil and the bias coil, the voice coil is connected with the super-audio oscillation circuit, and the bias coil is connected with the power amplification circuit through the slide resistor Rw and the resistor R1. The planar loudspeaker has the advantages of wide frequency response, high power, small distortion, thin body, arbitrary shape, simple structure, processing convenience, difficulty in damage, no magnetic disturbance and the like.