12results about How to "Stable output current" patented technology

The invention discloses a constructed wetland microbial fuel cell coupling device based on a novel three-dimensional electrode, and belongs to the technical field of sewage treatment, the device comprises a shell, and a bottom layer, an anode layer, a middle layer and a cathode layer are sequentially arranged in the shell from bottom to top. Wherein the bottom layer is filled with coarse gravels, and the middle layer is filled with fine gravels; the anode layer consists of a plurality of titanium tubes which are horizontally arranged and a titanium mesh for connecting the titanium tubes in parallel; openings are formed in the two ends of the titanium tube, through holes are formed in the titanium tube in an array mode, and the titanium tube is filled with a graphite felt core formed in a curled mode. The graphite felt core body can be used for a conductive material strengthening process and can also be used as a supporting material, and compared with an anode cage structure formed by a stainless steel net, the bearing strength is higher; the resistance of the metallic titanium is lower than that of the stainless steel mesh, so that electron transmission and improvement of electron transfer efficiency are facilitated, and the energy recovery efficiency and pollutant removal efficiency of the constructed wetland microbial fuel cell coupling device can be effectively improved.

According to the optical fiber laser constant-current driving circuit and the optical fiber laser, through the combined design of the front-stage BUCK voltage reduction module and the rear-stage linear constant-current control module, the working efficiency of a driving power supply can be effectively improved, and ripples in output current can be remarkably reduced. The preceding stage BUCK voltage reduction module realizes efficient voltage reduction through switch control, ensures voltage stability, and reduces energy loss at the same time. And the backward-stage linear constant-current control module keeps the constancy of the current by accurately adjusting the output current, so that the current ripple is further reduced, and the high requirement of the fiber laser on constant-current driving is met. The design ensures that the circuit outputs stable and low-ripple constant current while efficiently converting voltage, and the performance and reliability of the fiber laser driving power supply are greatly improved.

The invention provides an electrode impedance test system for physical therapy. The electrode impedance test system comprises a microcontroller, a D / A conversion circuit, a power amplification circuit, a voltage detection circuit, a current detection circuit and a boosting transformer circuit. The microcontroller generates a square wave signal, the square wave signal is converted into a sinusoidal signal through the D / A conversion circuit, and the sinusoidal signal is amplified through the power amplification circuit. The boosting transformer transmits the amplified sinusoidal signal to the electrode slice, and the secondary side of the boosting transformer is connected with the voltage and current sampling circuit and is used for collecting a differential signal. According to the system, the electrode impedance of the electrode plates is detected through voltage and current sampling of the pair of electrode plates, common-mode interference and signal distortion are eliminated through the differential signal amplification circuit and the full-wave precision rectification circuit, and high-precision acquisition and detection of signals are ensured. The detected and rectified signals are converted into digital signals through the A / D conversion circuit, and the digital signals are input into the signal input end of the microcontroller.

The utility model discloses a kind of DC mobile energy storage system commercial power wake-up circuit, including power supply electronic circuit;Energy storage delay subcircuit, energy storage delay subcircuit is parallelly connected in power supply electronic circuit;Current amplification subcircuit, current amplification subcircuit includes primary amplification branch and secondary amplification branch, primary amplification branch is parallelly connected in energy storage delay subcircuit, secondary amplification branch is parallelly connected in primary amplification branch;Load filter subcircuit, load filter subcircuit is connected in secondary amplification branch;Wake-up subcircuit, wake-up subcircuit is parallelly connected in load filter subcircuit.The utility model when commercial power is accessed, power supply electronic circuit starts power supply, energy storage delay subcircuit stores energy and delays false trigger, to output charging current is amplified after primary amplification branch, again secondary amplification branch is amplified, filter out ripple by load filter subcircuit, trigger wake-up subcircuit starts to wake up BMS, simplify commercial power power-up wake-up process, to improve operating convenience and wake-up efficiency.

The present application belongs to the technical field of power supply and distribution. A parallel three-level inverter modulation method, system, product, medium and equipment are proposed, which equivalent double parallel three-level inverters as a whole five-level inverter, inject zero sequence components to the initial three-phase reference signal to obtain the reference signal, identify the resultant vector through rounding and remainder operation, and then adjust the reference signal according to the sum of the three-phase state of the initial resultant vector to output a five-segment switching sequence, and then decompose the equivalent five-level reference signal into two sets of three-level reference signals, allocate the reference signals by dividing the half-carrier period and compare them with the triangular carrier to obtain a three-level vector sequence combination. The present application realizes the comprehensive optimization of common-mode voltage, zero-sequence circulating current and output current ripple, avoids complex sector judgment and duty cycle calculation, and reduces the implementation complexity and computational burden.

The embodiment of the invention provides a current source circuit and a control method of the current source circuit, the circuit comprises an operational amplifier, the positive input end of the operational amplifier is used for receiving band-gap reference voltage, the output end of the operational amplifier is connected with a first electrode of an MOS tube, the reverse input end of the operational amplifier is connected with a second electrode of the MOS tube, and the third electrode of the MOS tube is connected with a current input circuit; the resistance-adjustable circuit receives the output current of the current input circuit, one end of the resistance-adjustable circuit is connected with a second electrode of the MOS tube, the MOS tube is conducted based on the output voltage of the output end of the operational amplifier, and the output voltage of the second electrode of the MOS tube is transmitted to the reverse input end of the operational amplifier so that the output voltage of the operational amplifier can be kept stable. The resistance value of the resistance-adjustable circuit is adjusted so that the temperature coefficient resistance of the resistance-adjustable circuit is zero. The resistance value of the resistance-adjustable circuit is adjusted, so that the temperature coefficient resistance of the resistance-adjustable circuit is zero, and equivalent current with the temperature coefficient being zero is obtained.

A control circuit for a power converter includes a sensing circuit, a ramp signal generator, an error amplifier, a comparator, and a pulse width modulation (PWM) circuit. The sensing circuit is coupled to a first output circuit to provide a current sensing signal. The ramp signal generator is coupled to the sensing circuit and receives the current sensing signal to provide a ramp signal. The error amplifier receives a reference voltage and the output feedback voltage of the power converter to provide an error amplification signal. The comparator is coupled to the ramp signal generator and the error amplifier and receives both the ramp signal and the error amplification signal to provide a control signal. The PWM circuit is coupled between the comparator and the first output circuit, receives the control signal, and provides a PWM signal to control the first output circuit. The ramp signal generator adjusts the slope of the ramp signal based on the current sensing signal. This invention avoids ringing of the power converter's output voltage after unloading / unloading, thereby improving the stability of the system output.

The invention relates to a driving method of a three-phase conversion half-bridge. The method comprises the following steps: driving the three-phase conversion half bridge by a first commutation strategy; obtaining a first detection voltage, a second detection voltage and a third detection voltage of three bridge arms in the three-phase conversion half bridge; the first detection voltage is greater than the second detection voltage, and the second detection voltage is greater than the third detection voltage; and when the first detection voltage, the second detection voltage and the third detection voltage meet a preset condition, driving the three-phase conversion half-bridge by using a first driving strategy in a corresponding switching period so as to enable three bridge arms of the three-phase conversion half-bridge to perform normal commutation. When the first detection voltage, the second detection voltage and the third detection voltage meet the preset conditions, the three-phase conversion half-bridge is driven by the first driving strategy, so that short circuit of capacitors of two bridge arms is avoided, and the three-phase conversion half-bridge is further enabled to stably output current.

The present invention discloses a wireless power transmission system with high anti-offset characteristics, including a power supply E, a transmitting unit P1, a transmitting unit P2, a receiving unit S1, a receiving unit S2, a rectifier filter circuit and a load resistor connected in sequence. The transmitting unit P1 includes a transmitting coil T1 and an impedance unit Z01 connected in series, the transmitting unit P2 includes a transmitting coil T2 and an impedance unit Z02 connected in parallel, the receiving unit S1 includes a receiving coil R1 connected in series and an impedance unit Z03, and the receiving unit S2 includes a receiving coil R2 and an impedance unit Z04 connected in parallel. The transmitting coil T1 and the receiving coil R1 are connected by a mutual inductance M v Coupling, the transmitting coil T2 and the receiving coil R2 are connected by mutual inductance M i Coupling. Using mutual inductance M v With M i The characteristics of simultaneous increase or decrease under offset conditions greatly reduce the output fluctuation caused by the change in the relative position of the transmitting coil and the receiving coil, ensuring stable output under high offset conditions.

The present invention discloses a wireless power transmission topology with strong anti-offset performance based on multi-frequency energy parallel transmission. The control module outputs a driving square wave signal of a high-frequency inverter, so that the output voltage of the high-frequency inverter is a mixed superposition of dual-frequency or multi-frequency voltages. After passing through the primary multi-frequency shared compensation network, the dual-frequency or multi-frequency current simultaneously excites the primary transmitting coil, and the multi-frequency energy is transmitted to the receiving module in parallel through magnetic field coupling. The receiving module realizes dual-frequency or multi-frequency energy separation and decoupled transmission, and outputs AC voltage or current with each frequency respectively, which are rectified and filtered respectively and then combined and output to power the load. The design of the resonance parameters makes the output at different frequencies inconsistent with the change trend of mutual inductance. After the combined output, an output voltage or current that is insensitive to the change of mutual inductance is obtained, which greatly reduces the output fluctuation caused by the change in the relative position of the transmitting coil and the receiving coil, and ensures the stable output of the wireless power transmission system under high-offset conditions.

The present invention relates to a shore-based variable frequency power supply micro-power consumption full-power test method and system under weak power grid conditions, wherein the power supply variable frequency power supply V1 includes a frequency converter VFP1, the shore-based variable frequency power supply V2 includes a frequency converter VFP2, the energy-feeding load power supply V3 includes a frequency converter VFP3, the input end of the frequency converter VFP1 is connected to the shore-based high-voltage power supply, the output end of the frequency converter VFP1 is connected to the input end of the frequency converter VFP2, the output end of the frequency converter VFP2 is connected to the input end of the frequency converter VFP3, and the output end of the frequency converter VFP3 is respectively connected to the output end of the frequency converter VFP1 and the input end of the frequency converter VFP2; the energy-feeding load power supply V3 is used as a simulated load to test the shore-based variable frequency power supply V2, and after the shore-based variable frequency power supply V2 is tested, the shore-based variable frequency power supply V2 is put into use. The advantages of the present invention are: after the test loop forms a loop, no actual work is required, only the current needs to be increased to a predetermined test value, the energy consumption is small, and the power grid does not need to provide a large capacity.

The application discloses a heating wire heating power control circuit, method and electronic cigarette. The circuit is connected with the heating wire and comprises a power supply module, a current detection wire or a current detection resistor, a first heating wire wire, a second heating wire wire and a control module. The power supply module is connected with a battery voltage and a control end of the control module and one end of the current detection wire or the current detection resistor. One end of the current detection wire or the current detection resistor is also connected with a first detection end of the control module, and the other end is respectively connected with a second detection end of the control module and one end of the first heating wire wire. The other end of the first heating wire is connected with one end of the heating wire. One end of the second heating wire wire is connected with the other end of the heating wire, and the other end is grounded. The control module is used for controlling the power supply module to supply power to the heating wire and is also used for collecting the voltage between the current detection wire or the current detection resistor to control the heating power of the heating wire. The application can realize constant power control of the heating wire.