Please select the most similar patent number from A, B, C and D. Which number is?
A dynamic rectification control circuit (1), comprising: a resonant capacitor (C1) which is connected in parallel between a first antenna terminal (in1) and a second antenna terminal (in2) together with a resonant inductor (L) and used for forming a resonant circuit together with the resonant inductor to receive an external electromagnetic field and couple same to a rectification circuit (2); a rectification circuit, wherein input ends thereof are connected to the first antenna terminal and the second antenna terminal, which is used for converting an alternating-current power source coupled by the resonant circuit into a direct-current power source (Vdd_out) and outputting same and providing a power source for an amplitude limiting circuit, and at the same time, one path of an output end thereof is connected to the ground (GND), which is used for outputting the charge to the ground when the field intensity is too strong; and an amplitude limiting circuit, wherein a power source input end thereof is connected to a power source output end (V 1 ) of the rectification circuit, and an output end (V R ) thereof is connected to a control input end of the rectification circuit. When the voltages of the antenna terminals are too high, the dynamic rectification control circuit can conduct through the grounded path, so that the charges of the antenna terminals are output to the ground, and the quantities of electric charges of the antenna terminals are reduced, thereby reducing the rectified direct-current voltage. The dynamic rectification control circuit can prevent an over-voltage from damaging a load circuit, and can also prevent the occurrence of a phenomenon where the reception of a card reader terminal is saturated at the same time. In addition, also provided are a passive RFID comprising the dynamic rectification control circuit, and a method for performing dynamic rectification control on the circuit using the passive RFID.
A: Disclosed in the present invention is an alternating current source for detecting battery internal resistance in alternate current injection method. The alternating current source comprises an isolating step-down circuit, a rectifying circuit, an inverter circuit and an inductance capacitance (LC) resonance circuit which are connected in turn. An output end of the LC resonance circuit is reversely connected to the inverter circuit through a control circuit to form a closed loop control system. A non-direct capacitor is used in the LC resonance circuit. Also disclosed in the present invention is a corresponding control method of the alternating current source. The invention can inject current into one or more groups of high-voltage battery packs using a very low busbar voltage, thereby greatly reducing voltage stress of a power semiconductor component, significantly improving reliability of the system and simultaneously obviously improving system efficiency.
B: A rectification and amplitude limiting circuit having a variety of time constants, and a passive radio-frequency tag comprising the rectification and amplitude limiting circuit. By applying analogue control signals which have different time constants, i.e. which conduct a voltage amplitude adjustment at different switching speeds, to control ends of two discharging paths of the rectification and amplitude limiting circuit, the switching between full opening and full closing of the two discharging paths is realized, and adaptive discharging is conducted according to the quantity of electric charges at an antenna terminal and a condition of the energy level of the tag, so as to improve the demodulation capability of the tag, and increase the read and write distance of the tag.
C: A power supply of a single-phase electronic electric energy meter, comprising an industrial frequency transformer (T1), a rectifier circuit (D1), a filter circuit (C1), a sampling control circuit, a switch circuit (SW1), a step-down DC/DC circuit and a boost DC/DC circuit. An industrial frequency alternating current Vin, after being subjected to voltage step-down via the industrial frequency transformer, passes through the rectifier circuit and the filter circuit and generates a direct current voltage V1 at a direct current voltage end; the direct current voltage end is directly connected to an input end of the step-down DC/DC circuit; the step-down DC/DC circuit outputs a direct current voltage V2 and inputs same to the boost DC/DC circuit; and an output end of the boost DC/DC circuit provides a stable working power supply for a CPU and a measurement chip of the electric energy meter. One end of the sampling control circuit is connected to the direct current voltage end, and the other end is connected to a control end of the switch circuit; and an input end and an output end of the switch circuit are respectively connected to the input end and an output end of the step-down DC/DC circuit. The direct current voltage V1 can be connected to the boost DC/DC circuit via the switch circuit to enable an output voltage V3 of the output end of the boost DC/DC circuit to remain stable; and a current output by the output end of the boost DC/DC circuit is proportional to an instantaneous voltage output by the output end of the boost DC/DC circuit.
D: A charging circuit, a chip and a device. The charging circuit comprises: a magnetic induction circuit, a rectifying circuit, a switch circuit and a boost circuit, wherein an output end of the magnetic induction circuit is connected to an input end of the rectifying circuit; and the switch circuit is respectively connected to the rectifying circuit and the boost circuit. The magnetic induction circuit receives an electromagnetic signal sent by a transmitting end, and generates an alternating current according to the electromagnetic signal; the rectifying circuit converts the alternating current into a direct current; and the switch circuit switches on a path between the rectifying circuit and the boost circuit, so that the boost circuit boosts an output voltage of the magnetic induction circuit. In the solution, a switch circuit is controlled to switch on the path between a rectifying circuit and a boost circuit, such that the boost circuit is charged, so as to boost an output voltage of a charging circuit, and the boosted output voltage can ensure that a chip in which the charging circuit is located is started, thereby solving the problem of it not being possible to charge a device in which the charging circuit is located due to the fact that the chip in which the charging circuit is located cannot be started caused by the charging circuit being undervoltage.
Answer: B