6results about How to "Improve Noise Performance" patented technology

This utility model relates to a noise reduction structure for a DC motor, wherein the noise reduction structure (1) is disposed within a cavity for accommodating a commutator (2) and close to the sound source. The noise reduction structure (1) can be a honeycomb structure, a square structure, a circular structure, or a regular polygonal structure, and can be disposed on the bottom surface of the cavity, or simultaneously on the sidewalls and bottom surface of the cavity. The noise reduction structures (1) can be evenly distributed on the bottom surface and sidewalls of the cavity, or staggered. In addition, the noise reduction structure (1) can also be disposed within the cavity of a gearbox (5), including at the bottom of the gearbox cavity (6), or simultaneously on the bottom and cavity walls of the gearbox cavity (6). Using this noise reduction structure for a DC motor, the sound waves generated by the sound source are effectively reflected and canceled out by the noise reduction structure, thus reducing the noise of the DC motor and possessing certain practical value.

The application discloses a voltage-controlled oscillator and electronic equipment, comprising bias circuit, core circuit and buffer stage circuit connected in sequence, wherein the core circuit comprises PMOS cross-coupled pair, NMOS cross-coupled pair and LC resonant loop connected in parallel. Compared with the prior voltage-controlled oscillator, the core circuit of the voltage-controlled oscillator utilizes PMOS cross-coupled pair and NMOS cross-coupled pair to provide negative resistance, reduces the number and stack number of active devices in the core circuit, and is beneficial to optimization of noise performance of the voltage-controlled oscillator and low-voltage implementation. Meanwhile, the voltage-controlled oscillator adjusts the substrate voltage of the PMOS cross-coupled pair and the NMOS cross-coupled pair in the core circuit through the bias circuit, so that the voltage-controlled oscillator can work at low voltage and low power consumption, the current of the core circuit and the amplitude of the MOS tube transconductance changing with environmental factors such as temperature can be reduced, and the circuit robustness is improved.

According to the biplane DC-RF compound field driving coil system for the optical pump magnetometer, the complexity, noise and volume of the system are reduced and the measurement sensitivity and integration degree are improved by unifying the geometric configuration and differential parameters of the biplane, and particularly, the high-frequency magnetic field distortion and frequency dispersion effect in a magnetic shielding environment are optimized. Specifically, the problems of insufficient magnetic field uniformity, enhanced electromagnetic interference and RF magnetic field distortion in a large-volume area caused by non-uniform coil configuration in the traditional design are solved, so that the high uniformity of the magnetic field is realized, and the space utilization rate and the signal quality of a system are improved, and the system is characterized by comprising a standard coil unit and a radio frequency coil unit, the standard coil unit and the radio frequency coil unit both adopt a biplanar coil configuration after simulation optimization, the biplanar coil comprises a left planar coil and a right planar coil, and the left planar coil and the right planar coil are parallel, coaxially and symmetrically arranged on the two sides of a target area and used for generating and compensating a shimming magnetic field.

The application provides an isolated detection system and a vehicle. The isolated detection system comprises a power supply circuit, a signal input circuit, an isolation circuit and a signal processing circuit. The power supply circuit is configured to output a first low-voltage power supply. The signal input circuit is connected to a positive electrode of a high-voltage DC bus, a negative electrode of the high-voltage DC bus and the power supply circuit. The isolation circuit is connected to the signal input circuit and the power supply circuit. The signal processing circuit is connected to the isolation circuit and configured to determine the voltage of the high-voltage DC bus based on the output current of the isolation circuit. The system can directly convert the high-voltage power supply of the high-voltage DC bus into a low-voltage power supply and output the low-voltage power supply to the high-voltage side circuit through the power supply circuit, so that the high-voltage side circuit can work normally, the power supply cost is low, the high-voltage side power supply and the low-voltage side power supply are isolated from each other, the power supply stability is high, the use reliability of each device in the system is improved, and the detection and operation reliability of the system are improved.

The application claims a high-gain operational amplifier circuit for Sigma-Delta ADC. The circuit comprises a main operational amplifier, a gain-improving auxiliary operational amplifier, a bias circuit and a switched-capacitor common-mode negative feedback circuit. The main operational amplifier serves as the main body of the circuit, has a high gain and a wide bandwidth; the auxiliary operational amplifier improves the output impedance and effectively improves the DC gain of the operational amplifier; the bias circuit is used to provide appropriate DC bias voltage for the main operational amplifier and the auxiliary operational amplifier; the switched-capacitor common-mode negative feedback is used to stabilize the output common-mode voltage. The application uses the auxiliary operational amplifier to improve the gain, ensures a high input-output swing of the operational amplifier, improves the DC gain of the operational amplifier, adopts a symmetrical switched-capacitor common-mode negative feedback, ensures the bandwidth range and reduces the nonlinearity of the circuit.

The application discloses a hybrid power supply circuit and relates to the technical field of transformers. The circuit comprises a primary circuit and a secondary circuit arranged on one side of the primary circuit. The primary circuit comprises a first primary coil and a second primary coil for electrically coupling a voltage source respectively. The first primary coil and the second primary coil are subjected to common mode filtering and / or differential mode filtering by adjusting the phase. The secondary circuit comprises a first secondary coil and a second secondary coil for electrically coupling a load respectively. The position of the first secondary coil corresponds to the first primary coil, and the position of the second secondary coil corresponds to the second primary coil. The first secondary coil and the second secondary coil generate induced electromotive forces with the first primary coil and the second primary coil respectively. The hybrid power supply circuit can simultaneously have the functions of noise suppression and energy conversion.