91results about How to "Reduce parameter requirements" patented technology

The invention provides a circuit and a method for switch power supply feedback voltage detection and sampling and holding. The circuit provided by the invention comprises a clock control circuit, a control sampling clock, a sampling and holding circuit, a waiting state control circuit, a learning state control circuit, an increment control circuit, a system control circuit and a delay circuit, wherein the sampling and holding circuit samples an input voltage at different time in two paths and selects a larger value to be output; the waiting state control circuit controls sampling and waits till a waveform is stable; the learning state control circuit controls the time sequence of a learning state; the increment control circuit controls an increment circuit which realizes two adjacent times of sampling; the system control circuit controls a finite state machine together with other circuits; and the delay circuit realizes required delay. In the method of the invention, an entire switching period of a switch power supply is divided into five states in turn: a PWM open state, a waiting state, a learning state, a detection state and a demagnetization ending state; the five states form the finite state machine; and the detection and sampling and holding of a feedback voltage can be realized by controlling the state switching and output of the finite state machine.

The invention discloses a laser-induced fluorescence combustion field parameter measuring device which comprises a light source system and a detection system, wherein the light source system comprises a laser (5), an optical fiber coupling lens (1), a plastic optical fiber bundle (2), a spherical lens (3) and a cylindrical lens (4), wherein the optical fiber coupling lens (1), the plastic optical fiber bundle (2), the spherical lens (3) and the cylindrical lens (4) are arranged in the laser transmission direction in sequence; an optical fiber configuration section on the incident end surface of the plastic optical fiber bundle (2) is matched with a light beam section of the laser (5), and the emergent end surface of the plastic optical fiber bundle (2) is configured into a linear shape; and a cylindrical center line of the cylindrical lens (4) is parallel to an optical fiber configuration line on the emergent end surface of the plastic optical fiber bundle (2). The laser-induced fluorescence combustion field parameter measuring device has the benefits that a lamellar light beam with uniform light intensity in an area on the light beam transmission direction is realized, the demands that the combustion flow field two-dimensional parameter measurement is realized by adopting a planar laser-induced technology are satisfied, the combustion flow field parameter measurement under the strong-vibration and strong-noise impact environment are simultaneously satisfied, and the environmental adaptability of the system is improved.

The invention relates to the field of kitchen appliances, and discloses a control method for a range hood, a controller, a control device and the range hood. The temperature, detected in a time window, of a furnace end region of a gas stove is acquired, the temperature fluctuation level in the time window is determined according to the acquired temperature, finally, starting of the range hood is determined according to the temperature fluctuation level, thus, ignition of the gas stove can be accurately recognized, and automatic control over the range hood is achieved. By the adoption of the method, the parameter requirement on an infrared sensor is low, the single-point acquisition low-cost infrared temperature sensor can be adopted, the response speed can be rapidly recognized, good recognition accuracy is achieved, and therefore the reliability and the accuracy of linkage control of the range hood and the gas stove at low cost are achieved.

The invention discloses a transducer drive induction motor stator turn-to-turn short circuit fault diagnosis method; the method calculation is simple, easy to realize and has high robustness, the parameter requirement to the induction motor is low. A voltage sensor is added, the transducer switch sideband harmonic wave zero-sequence component is extracted and analyzed for detecting the fault of the ring opening and closing operation and speed regulation operation for the motor system, the method is suitable for the modulation modes as SPWM, SVPWM, the application range is wide, the dynamic effect is good, the recognition precision is high, the stator turn-to-turn short circuit fault can be diagnosed at real time for giving the fault degree index.

The invention discloses a method for preparing biodiesel from oil with a high acid value. The method comprises the steps as follows: mixing oil with a high acid value with methanol, adding compound acid catalyst, carrying out esterification reaction, removing crude methanol through flash vaporization, adding potassium hydroxide methanol solution, performing transesterification reaction, removing crude methanol through flash vaporization again, standing liquid from which crude methanol is removed and settling for 4 to 5 hours, and removing glycerol through separation to obtain crude biodiesel.The method has the characteristics of low device investment, simple process, low manufacturing cost, high reaction rate and high conversion rate of products.

The invention relates to an efficient white smoke removing device for flue gas after WFGD (wet flue gas desulfurization) and an implementation method of the device, and belongs to the technical fieldof chemical engineering and environmental protection. The device comprises a booster fan, a white smoke removing tower and a cooling tower, wherein an inlet of the booster fan is connected with a fluegas guide pipe; an outlet of the booster fan is connected with a flue gas inlet of the white smoke removing tower; a spraying layer and a surface air cooler are arranged in the white smoke removing tower; a chimney is arranged at the top end of the white smoke removing tower; a solution tank is connected with the bottom of the white smoke removing tower; the spraying layer is connected with the solution tank; the solution tank is connected with a solution pump B, and then a solution flows to an inlet of a generator; an outlet of the generator is connected with a heat exchanger and then is connected with the solution tank; a water outlet of the heat exchanger is connected with an inlet of the cooling tower; a water inlet of the heat exchanger is connected with an outlet of the cooling tower; the inlet of the cooling tower is connected with an outlet of the surface air cooler; the outlet of the cooling tower is connected with an inlet of the surface air cooler. According to the efficient white smoke removing device for flue gas after WFGD and the implementation method of the device, flue gas is efficiently dehumidified by a LiBr solution, so that when the flue gas moves to an outletof the chimney, no white smoke is produced.

The invention discloses a retrieval structure of an optical packet head used in an exchange network of an asynchronous optical packet, which comprises a light splitter, a reflective semiconductor amplifier, a first circulator, a second circulator and a coupler; an input terminal of the light splitter is connected with packet input waveguide; a first output terminal of the light splitter is connected with a d port of the second circular through fiber delay lines, so that control signals which pass through the light splitter and are delayed are inputted to the reflective semiconductor amplifier; a second output terminal of the light splitter is connected with an a port of the first circulator; a b port of the first circulator is connected with the input/output terminal of the reflective semiconductor amplifier; a c port of the first circulator is connected with a first input terminal of the coupler; the input/output terminal of the reflective semiconductor amplifier is connected with an e port of the second circulator; an f port of the second circulator is connected with a second input terminal of the coupler. The retrieval structure of the optical packet head can increase on-off ratio of a system.

The invention relates to a separation structure of optical packet heads and payload used in an asynchronous optical packet switching network, and is characterized in that: the structure comprises an optical power splitter and a second multimode interference coupler; an upper output port of the optical power splitter is connected with a first multimode interference coupler and the upper output port of the optical power splitter is connected with an input end of the first multimode interference coupler; a lower output port of the optical power splitter is connected with the other input end of the first multimode interference coupler through an optical fiber delay line; an output end of the first multimode interference coupler is connected with an input end of the second multimode interference coupler through a first semiconductor optical amplifier; the other output end of the first multimode interference coupler is connected with the other input end of the second multimode interference coupler through a second semiconductor optical amplifier; detection optical packet heads are outputted from a lower output port of the second multimode interference coupler; the detection optical payload is outputted from an upper output port of the second multimode interference coupler.

The embodiment of the invention is suitable for power distribution field, and provides an electric servo transformer and a servo system thereof. In the electric servo transformer, the input terminal is connected to a three-phase alternating current; an output terminal is connected with a servo unit. The servo transformer is characterized in that the input terminal of the electric servo transformer is connected with a bridge stack set composed of at least two rectifying elements, and the three-phase alternating current is inputted into the electric servo transformer and outputted into the servo unit after rectifying by the bridge stack set. The circuit of the electric servo transformer is simple, and the electric servo transformer has the advantage of low request to element parameter, easy implementation, low cost, low failure rate, easy maintenance and the like; the performance of resisting lightning stroke and high voltage great current is more excellent, and the protective capability is strong.

The invention designs a space charge density measuring apparatus. The invention combines the advantages of an ion counting method and a charge screening method, and can realize the accurate measurement of the charge density in the wide particle size range under the condition that the parameters of the measuring device are low in requirement and the size is small. The apparatus comprises a shielding layer, an insulating layer, an ion counting method sensor, a charge screening method sensor, a flowmeter, an ion counting method bias power supply, a negative ion weak current measurement module, a positive ion weak current measurement module, a charge measurement module, a measurement result processing module and a gas intake device.

The invention discloses a T-shaped rectifying circuit and a corresponding three-phase rectifying circuit, By utilizing an internal circuit topology, A first controllable switch and a second controllable switch are both soft-switched. Namely, zero voltage switch, zero current switch or zero voltage zero current switch, or on-off switch with limited dv/dt and di/dt, which reduces the on-off power consumption of controllable switch, and makes the on-off power consumption of T-type rectifier circuit can be very small when the working frequency is relatively high, so that the on-off power consumption of T-type rectifier circuit is very low. In addition, the present application builds on conventional T-type rectifying circuits, Only one inductor is added, Four diodes and two capacitors do not require additional controllable switches and control circuits, and devices can be added without substantially changing the internal circuit layout of the traditional T-type rectifier circuit, so that the circuit topology structure is compact and the bus bar design is simple, thereby facilitating the electrical layout and structure design, and reducing the reconstruction cost.