223 results about "Preamplifier" patented technology

The invention provides a signal acquisition system of a photoelectric detector. In the signal acquisition system, a transimpedance pre-amplification circuit is arranged at the output end of the photoelectric detector, and a passive high-pass filter circuit is connected between the transimpedance pre-amplification circuit and a post-voltage amplification circuit. And a feedback network is formed in the transimpedance pre-amplification circuit and is used for converting a current signal output by the photoelectric detector into a proportional first voltage signal and outputting the proportional first voltage signal. The filter circuit is a third-order LC high-pass filter circuit and is used for suppressing direct current, low frequency and self-beat frequency components and keeping a 10-90MHz pass band flat. The rear voltage amplification circuit adopts a voltage amplification structure of a voltage operational amplifier, the voltage gain Av is 6-10, and the super-band gain is limited through a shunt capacitor. According to the embodiment of the invention, through the structure and parameter setting, the noise gain peak value is suppressed, and the system stability is improved.

A latch comparator is disclosed. The latch comparator includes a first reservoir capacitor; a preamplifier including first and second transistors respectively connected to first and second inputs, the first and second transistors selectably connectable to a first terminal of the first reservoir capacitor, and third and fourth transistors respectively connected to the first and second inputs, the third and fourth transistors selectably connectable to a second terminal of the first reservoir capacitor; and a latch, including a first portion serially connected between the first and third transistors and connected to a first output, and a second portion serially connected between the second and fourth transistors and connected to a second output.

The utility model discloses a high-density deployment noise monitoring micro-station in the technical field of noise monitoring, which comprises a capacitive sensor, a preamplifier, an ADC (analog to digital converter) circuit, an AGC (automatic gain control) circuit, an MCU (microprogrammed control unit) system and a wireless communication module. The pre-amplifier is used for amplifying an analog signal according to a certain multiple, the ADC circuit is used for the analog-to-digital conversion circuit and converting an analog electric signal into a digital electric signal, the AGC control circuit is used for the automatic gain control circuit, and the MCU system is used for processing, operating and storing received data and controlling an AGC amplification multiple and a communication mode. The wireless communication module is used for transmitting data processed by the micro-station MCU system through a long-distance wireless communication technology or receiving external data, low power consumption and miniaturization of the noise monitoring station are achieved through combination of all aspects, the noise monitoring station can be conveniently installed on any fixable places such as a wall, a trunk and an electric pile, and high-density deployment is achieved.

The present application relates to the field of analog integrated circuit technology, and particularly relates to a kind of sampling and holding circuit based on noise cancellation.The present application handles sampling noise by introducing noise cancellation technology, input signal is directly connected to the upper plate of C1, C1 samples during S1 switch is closed;The output end of operational amplifier is connected with the lower plate of C2 through S2 switch, C2 samples sampling noise during S2 switch is closed, C2 two ends are connected with C1 two ends through S3 switch, C1 and C2 share charge during S3 switch is closed;Dynamic operational amplifier output end is connected with latch at the same time, so as to use operational amplifier as the preamplifier of comparator.The present application effectively suppresses the deterioration of sampling noise under the condition of reducing sampling capacitor, and dynamic operational amplifier greatly reduces the power consumption and noise of sampling and holding after introducing operational amplifier, and C2=C3 can also be set to make the gain of dynamic operational amplifier in noise elimination stage and subsequent as comparator preamplifier be equal, further improve the precision of circuit.

A first circuit receives a single-ended signal and a reference voltage. The first circuit shifts a common mode of the single-ended signal based on a level-shifting current. A preamplifier receives the single-ended signal and the reference voltage from the first circuit and amplifies the single-ended signal to obtain an amplified signal. A decision feedback equalizer (DFE) system receives the amplified signal and the reference voltage from the preamplifier. The DFE system generates a first average signal height of the amplified signal above the reference voltage and a second average signal height of the amplified signal below the reference voltage. A second circuit provides the level-shifting current to the first circuit and adjusts the level-shifting current based on a linearity parameter associated with the amplified signal.

A kind of analog-digital converter is disclosed.The analog-digital converter includes: comparator, is configured to: input signal is compared with reference signal, and output comparison signal indicating corresponding comparison result;Control logic is configured to output control signal for adjusting reference signal based on comparison signal;And reference signal adjusting circuit is configured to adjust reference signal based on control signal.Comparator includes: first preamplifier, is configured to: using first transistor with first size, the difference between input signal and reference signal is amplified;Second preamplifier, is configured to: using second transistor with second size different from first size, the difference between input signal and reference signal is amplified;And latch, is configured to: using at least one of the output of first preamplifier and the output of second preamplifier, comparison signal is generated.First preamplifier and second preamplifier share latch.

The invention discloses a piezoelectric circular tube transducer which comprises a piezoelectric ceramic circular tube. The pre-amplifier is arranged in the fixed structural member; the fixing structural member is filled with an elastic material so as to elastically fix the pre-amplifier; the fixed structural member is arranged in the piezoelectric ceramic circular tube, the fixed structural member is sealed at one end of the piezoelectric ceramic circular tube, and the other end of the piezoelectric ceramic circular tube is sealed by an end cover; the first metal lead terminal is inserted into the lead terminal jack of the fixed structural member, and a signal output lead of the pre-amplifier is electrically connected with the first metal lead terminal; a second metal lead terminal is inserted into a corresponding lead terminal jack of the fixed structural member, and a power supply lead of the pre-amplifier is electrically connected with the second metal lead terminal; an input lead of the pre-amplifier is connected with a positive electrode lead of the piezoelectric ceramic circular tube; and a negative lead of the pre-amplifier is connected with a negative electrode lead of the piezoelectric ceramic circular tube. External electromagnetic noise can be effectively isolated.

This invention discloses an active coupling cavity device and calibration method for calibrating a standard microphone. A sound source adapter is located at the signal input end of the active coupling cavity. A multi-channel sound field distribution structure is located within the active coupling cavity, comprising eight acoustic channels evenly distributed circumferentially along the central axis of the active coupling cavity. A symmetrical clamping assembly constrains the reference microphone and the microphone under test to be symmetrical about the central axis of the active coupling cavity. A coaxiality test ring assembly rigidly constrains the axes of the reference microphone and the microphone under test to coincide with the central axis of the active coupling cavity. The calibration test system includes a signal generator, a sound level meter under test, a preamplifier, a measurement amplifier, a bandpass filter, and a digital voltmeter. The multi-channel uniformly distributed sound field structure solves the problem of uneven sound pressure distribution caused by unidirectional input, and the symmetrical clamping assembly and the coaxiality test ring assembly respectively solve the problem of poor consistency in low-frequency and high-frequency phase measurements.

A radio frequency (RF) receiver assembly (100) for use in a magnetic resonance imaging (MRI) system is described. The receiver assembly (100) comprises a primary resonant circuit (101) coupled to a preamplifier (106) via capacitive coupling, and a secondary resonance circuit (104) comprising of at least one inductor (104a) coupled between a first switch (103) and the capacitive coupling. The first switch (103) is circuited between the primary (101) and the secondary (104) resonant circuits, and the preamplifier (106).

The invention discloses a magneto-optical effect-based dynamic zooming method and an optical system, and the method comprises the steps: arranging at least one magneto-optical crystal between a pre-amplifier and a main amplifier, so as to achieve the dynamic zooming through the magneto-optical effect; wherein the magneto-optical crystal is obtained by combining anisotropic materials with matched refractive indexes, and the anisotropic materials are processed into complementary parabola shapes. According to the invention, the magneto-optic effect is utilized to realize dynamic zooming, and the mode of complementary combination of the crystals with matched refractive indexes is utilized to solve the problem that the additional wavefront shape does not conform to the demand. Compared with an electro-optical effect scheme, an applied magnetic field is a uniform magnetic field along a transmission direction, so that a depolarization problem caused by a transverse component is avoided; compared with the scheme of aperture division, grating division and the like, the dynamic zooming can be realized on the premise of not influencing the output capability of the laser.

The utility model discloses a quartz enhanced photoacoustic spectrometry gas detection system based on coaxial main and auxiliary resonance tubes, which comprises a signal generator, an adder, a laser, a collimator, a gas sensing device, a preamplifier, a lock-in amplifier, a data acquisition system and a computer, a laser is arranged on one side of the summator, a collimator is arranged at the output end of the laser, a gas sensing device is arranged on one side of the collimator, a pre-amplifier is arranged on the rear side of the gas sensing device, and the output end of the pre-amplifier is connected with the input end of the phase-locked amplifier. The output end of the lock-in amplifier is connected with the data acquisition system, and the data acquisition system is connected with the computer. The ultra-low trace gas detection device is used for ultra-low trace gas detection, gas concentration detection is rapid, accurate and effective, and the minimum detection limit of gas can be obviously enhanced.

This invention discloses a magnetoencephalogram (MEG) compatible preamplifier method and device, which allows the MEG preamplifier to be placed within a magnetically shielded device. This invention achieves weak magnetism in the preamplifier circuit through the design of component selection and distribution; improves anti-interference capability and transmission stability by designing the MEG amplification factor and signal conditioning process; implements secondary amplification, power supply, and acquisition outside the magnetically shielded device, placing strongly magnetic components away from the weak magnetic environment to complete the entire acquisition process; and adopts a modular design, reducing the number of channels on each circuit board by distributing electrode channels, thereby reducing the size and facilitating the arrangement of the preamplifier system within the limited magnetically shielded space. This invention achieves weak magnetism in the preamplifier circuit, enabling high-quality brain-computer magnetic synchronous acquisition when placed within a magnetically shielded space.

The application relates to the field of integrated circuit design, in particular to a double-tail dynamic comparator based on a feedback structure, which comprises a preamplifier, a latch and a positive feedback structure which are cascaded with each other; the preamplifier comprises input ends VIP and VIN, output ends fn and fp, and is used for amplifying comparison signals of the input ends; the latch is used for carrying out digital judgment on the amplified comparison signals and latching a judgment logic level; and the positive feedback structure is used for providing a discharge path for fn and fp and increasing a differential voltage between fn and fp. The application introduces the design of the positive feedback structure, adds a new discharge path to the output node of the amplifier to accelerate the pre-amplification speed, and increases the differential voltage between the output nodes fn and fp, so as to reduce the regeneration time of the latch, inhibit the influence of non-ideal factors on the comparator when the input differential signal is small, and accelerate the comparison speed.

The disclosure provides a detection system based on proximity switches and a vehicle sampling device, wherein the detection system comprises a plurality of proximity switches, a power module and a control module; the proximity switch comprises a first power supply end, a second power supply end and a signal output end; the power module comprises a first power supply line and a second power supply line with opposite polarities; the signal output end of the first proximity switch and the first power supply end of the second proximity switch in adjacent proximity switches are connected, the first power supply line is connected with the first power supply end of the first proximity switch in all proximity switches, the second power supply line is connected with the second power supply end of each proximity switch, and the signal input end of the control module is connected with the signal output end of the last proximity switch in all proximity switches. In the detection system based on proximity switches and the vehicle sampling device, the ''and'' logic function of the plurality of proximity switches is realized by using series connection, so that the occupation of multiple channels in the control module and the increase of the preamplifier are avoided.

1. The name of the design product: pre-stage audio amplifier of electron tube. 2. The use of the design product: household audio equipment. 3. The design points of the design product: in shape. 4. The picture or photo that best shows the design points: perspective view 1.

This invention provides a design method for a high-order matching network applied to an ultra-wideband amplifier. It involves deriving equivalent modules for the single-port preamplifier input and output stages; determining the internal structure of the high-order matching network and the transformer coupling coefficient; analyzing and obtaining the mismatch coefficient of the high-order matching network; and transforming the calculation of the load resonator quality factor into solving the constraint conditions based on the constraints between the transformer coupling coefficient, the high-order matching network mismatch coefficient, and the load resonator quality factor. The source resonator quality factor is then obtained based on the mismatch relationship between the load resonator quality factor and the high-order matching network. Finally, the parameter values ​​of the internal components of the high-order matching network are determined, resulting in the final designed high-order matching network. Compared to existing technologies, this invention achieves impedance matching between the source and load over an ultra-wideband range and enables high-gain flatness amplification within the ultra-wideband range.

The application relates to the field of optical communication technology, and provides a device and method for loopback fast optical power recovery and a long-distance optical transmission system. When the optical power of first service light is not in a normal range, a loopback light switch unit is switched to a first loopback state, second service light of the same site is conducted to a pre-amplifier, the input optical power of the pre-amplifier is recovered to normal, and the output optical power of the pre-amplifier in a fault state is ensured to be the same as in a normal state; when the optical power of the second service light is not in the normal range, the loopback light switch unit is switched to a second loopback state, the first service light of the same site is transmitted to a remote site, the optical power to the remote site is recovered to normal, and the optical power to the remote site in the fault state is ensured to be the same as in the normal state; thus, the influence on the input of a downstream optical multiplexing section is minimized, and the problem that the WSS adjusting speed is too slow in the prior art is solved.

The present application relates to a wearable impedance measurement method and device based on alternating voltage excitation, the method comprising: in the case of determining that three electrode pieces are not worn, inputting a micro voltage excitation signal generated by a micro voltage excitation module to the in-phase input end of a preamplifier through a switching circuit, and determining the amplification multiple of the preamplifier based on the input end reference resistance of the preamplifier and the first output frequency component of the preamplifier; in the case of determining that the three electrode pieces are worn, inputting the micro voltage excitation signal to different input ends of the preamplifier through the switching circuit; and determining the wearable impedance of each electrode piece based on the amplification multiple of the preamplifier, the second output frequency component of the preamplifier, and the series-parallel connection relationship among the three electrode pieces. Based on this, the requirements for the limited value of the patient's leakage current can be met, and accurate impedance measurement among the three electrode pieces can be realized at low cost.

The application provides a kind of mine intrinsic safety type cable insulation fault on-line monitoring method and system, it is related to coal mine underground high-voltage cable insulation fault monitoring technical field, the method comprises: by mine intrinsic safety type high-frequency pulse signal sensor coupling cable ground wire on partial discharge current pulse signal, obtain high-frequency pulse signal;Analog conditioning is carried out to high-frequency pulse signal, and the analog signal after conditioning is obtained;The analog conditioning includes analog filter, preamplifier and impedance matching;Anti-aliasing filtering is carried out to the analog signal after conditioning, and the filtered signal is obtained;The analog signal in target band is extracted by selecting target band to the filtered signal;The analog signal in target band is converted into digital signal by A / D analog-digital conversion.The application identifies fault type, source and severity by cloud collaboration and multi-technology fusion, and real-time early warning visualization helps operation and maintenance to respond quickly, reduces accident risk.

The application relates to a thermoelectric array and a signal readout circuit thereof, the thermoelectric array comprising: a plurality of sensor pixel elements; and a readout circuit comprising a plurality of signal processing channels, each signal processing channel comprising: a preamplifier for amplifying a sensor signal, the preamplifier being a single-stage amplifier; and an analog-to-digital converter connected to an output of the preamplifier, the analog-to-digital converter being a delta-sigma analog-to-digital converter; wherein each signal processing channel is configured to process sensor signals output by i sensor pixel elements, i being a positive integer and not greater than the square root of the number of sensor pixel elements in the thermoelectric array divided by 4. The application effectively reduces the noise bandwidth of the signal channel, thereby effectively improving the signal-to-noise ratio of the signal processing channel, effectively improving the system performance, and significantly improving the thermal temperature resolution; at the same time, because the frequency is reduced, the area and power consumption of the preamplifier and the analog-to-digital converter can be significantly reduced.

An exemplary embodiment of the invention relates to an electrical amplifier (10) comprising a differential preamplifier (PA) having a first output port and a second output port, and a downstream amplifier stage (DAS) having a first output unit and a second output unit; wherein the first output unit is connected to the first output port of the differential preamplifier (PA) and the second output unit is connected to the second output port of the differential preamplifier (PA); and wherein a negative impedance converter is electrically located in at least one of said differential preamplifier (PA) and said downstream amplifier stage (DAS).

Geometry and construction of the signal cabling characterized by: • the position of the signal cables between the connector and the vacuum feedthrough to the warm preamplifier is in sinusoidal loops; compare Figure 1, markings 2 and 3

The invention relates to the field of environment monitoring and analyzing instruments, and particularly discloses a portable radon detector which comprises a silicon photomultiplier sensor unit, a low-noise preamplifier unit, a comparator circuit and an STM32 main control module. By adopting the EQR-15 series silicon photomultiplier, the 300 [mu] m epoxy resin protective layer on the surface of the EQR-15 series silicon photomultiplier can directly emit light under the bombardment of alpha particles, the advantages of the integration of a photodiode and the high signal amplitude of a scintillator are integrated, and the detection sensitivity and the signal-to-noise ratio are remarkably improved while an independent scintillator is omitted. Aiming at weak current signals, a low-noise pre-amplification circuit with a TL084CDR operational amplifier as a core is designed, and a pulse shaping and emitter follower is arranged, so that the problems of signal amplification and interference resistance are effectively solved. The main control module realizes accurate capture and counting of alpha particle pulses through ADC sampling, hardware triggering and DMA storage in combination with a threshold self-adaption and baseline tracking algorithm.

The invention provides a battery management system, a control method thereof and an electric-assisted bicycle using the same. The battery management system comprises an active pre-stage assembly, a direct-current voltage conversion circuit, a switching circuit and a microprocessor. The active pre-stage component is connected to a shared pin. The switching circuit is connected between the DC voltage conversion circuit and the shared pin. The microprocessor is connected to the active preceding stage assembly and the switching circuit. If the shared pin is set to be used for receiving a power button signal, the microprocessor controls the switching circuit to be switched off, so that a power switch control path is formed between the shared pin and the active preceding-stage assembly. If the shared pin is set to be used for outputting a direct current power supply, the microprocessor controls the switching circuit to be switched on, so that a direct current power supply output path is formed between the shared pin and the direct current voltage conversion circuit.

The application belongs to the field of piezoelectric MEMS sensors, and relates to a piezoelectric MEMS ultrasonic sensor ranging circuit and a ranging method, which comprise an MCU, a high-voltage pulse driving circuit, an adaptive impedance matching network, a piezoelectric MEMS ultrasonic transducer, an active damping network, a preamplifier, a band-pass filter and a time gain controller; the high-voltage pulse driving circuit can greatly improve the emission sound pressure of the transducer and improve the measurement range; a controllable switch is designed at one end of the damping resistor, which can improve the emission efficiency and reduce the residual vibration, thereby reducing the measurement blind area; the adaptive impedance matching network is introduced, which can adjust the impedance inconsistent between different devices due to temperature and aging degree to the impedance matched with the ranging circuit, effectively improve the sensitivity and emission efficiency of the device, and the high sensitivity can improve the distance measurement precision of the ranging circuit.

The invention belongs to the technical field of radiation monitoring, and particularly relates to a design method of a wide-range NaI (T1) detector, which comprises the following steps of: 1, connecting all lines of the NaI (T1) detector, and opening a multi-channel analyzer; 2, a 137Cs radioactive source is adopted, different preamplifier electronic gains are adjusted, the relation between the high voltage and the channel position where the characteristic energy of the 137Cs radioactive source is located is established, and energy spectrum data are output; 3, according to the output energy spectrum data, preamplifier electronic gain and linear amplifier high voltage needed by the detector are determined; and 4, under the determined preamplifier electronic gain required by the detector and the high voltage condition of the linear amplifier, different radioactive sources are adopted to carry out energy calibration on the detector, and whether digital gain needs to be adjusted is determined according to the energy calibration. According to the method, the measuring range of the sodium iodide gamma-ray spectrometer can be expanded, so that the sodium iodide gamma-ray spectrometer can cover high-energy radiation monitoring of 3MeV-10MeV or above.

This invention relates to a detection device for detecting partial discharge in substation equipment, comprising an ultrasonic sensor module 1, a preamplifier 2, an IED front-end detection unit 3, a detection host 4, and an IED memory 5. The ultrasonic sensor module 1 is connected to the IED front-end detection unit 3 via the preamplifier 2, and the IED memory 5 is also connected to the IED front-end detection unit 3. The IED front-end detection unit 3 communicates with the detection host 4. The ultrasonic sensor module 1 includes an ultrasonic sensor 11 and a sensor protection unit 12. The ultrasonic sensor 11 is installed within the sensor protection unit 12, which is mounted on a substation inspection robot. Compared with existing technologies, this invention has advantages such as effectively preventing damage to the ultrasonic sensor due to excessive robot movement, safety and reliability, and strong versatility.

According to the invention, a radio frequency antenna system (1) for a magnetic resonance imaging device comprising a radio frequency coil (2) which, when mounted in a bore of the magnetic resonance imaging device has a total coil impedance composed of a coil impedance and a patient-specific impedance of a patient, a preamplifier (3) connected to the radio frequency coil (2), by means of which a signal received by the radio frequency coil (2) can be amplified and an amplified output signal can be output, a matching network (4) which is interconnected between the radio frequency coil (2) and the preamplifier (3) with which the total coil impedance of the radio frequency coil (2) is adjustable and a controller (5), wherein the radio frequency coil (2) comprises a first coil loop (6) and at least one further coil loop (7), the controller (5) is connected to the radio frequency coil (2), the matching network (4) and the preamplifier (3) and the controller (5) is adapted for noise impedance matching between the radio frequency coil (2) and the preamplifier (3) as a function of patient-specific parameters by controlling the employment of the first coil loop (6) and the at least one further coil loop (7) and by controlling the matching network (4). In this way, a radio frequency antenna system with improved impedance matching is provided.

An optical network element detects an input optical signal at a preamplifier input and sets an output power level of the preamplifier at a predetermined Automatic Power Reduction (APR) power level. The optical network element starts an APR timer that expires after a first predetermined time period. While the APR timer is running, the optical network element measures an input power level of the input optical signal and calculates a span loss as a function of the difference between the predetermined APR power level and the measured input power level. After the expiration of the APR timer, the optical network element adjusts the output power level of the preamplifier output based on the calculated span loss.