CN-224218117-U - Low-noise power supply path management charging circuit and power supply system of electric equipment

CN224218117UCN 224218117 UCN224218117 UCN 224218117UCN-224218117-U

Abstract

The utility model discloses a low-noise power supply path management charging circuit and an electric equipment power supply system, which are used for switching on and off a lithium battery and electric equipment according to a charging power supply. The high-frequency noise output by the power supply is obviously reduced, the electric equipment is ensured to obtain a purer and stable power supply, and the high-frequency noise power supply is particularly suitable for precise electronic equipment with higher requirements on the quality of the power supply. The design is helpful for reducing the influence of power supply noise on sensitive instruments or equipment and improving the working accuracy of the equipment.

Inventors

WANG YILI
YANG XIAO
Fang Guanzhen
CHEN YI
Jin Jicun

Assignees

杭州爱华仪器有限公司

Dates

Publication Date: 20260508
Application Date: 20250428

Claims (6)

1. A low noise power path management charging circuit for switching on and off a lithium battery and a powered device according to a charging power supply, comprising: the power supply is connected to the detection unit and the path switching-off unit; the power supply access detection unit is electrically connected with the path switching-off unit; The lithium battery is electrically connected with the electric equipment through the path switching-off unit; the power supply access detection unit is electrically connected with the charging power supply; The path turn-off unit comprises a first PMOS tube and a second PMOS tube; The drain electrode of the first PMOS tube is electrically connected with the output end of the lithium battery, the source electrode of the first PMOS tube is electrically connected with the source electrode of the second PMOS tube, and the drain electrode of the second PMOS tube is electrically connected with the electric equipment; The source electrode of the first PMOS tube is electrically connected with the power supply access detection unit; The grid electrode of the first PMOS tube is electrically connected with the grid electrode of the second PMOS tube and then is electrically connected with the power supply access detection unit.
2. The low noise power path management charging circuit of claim 1, wherein said power supply access detection unit comprises a PNP transistor, an NPN transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor; The charging power supply is grounded through a third resistor and a fifth resistor in sequence, one end, connected with the third resistor and the fourth resistor, of the charging power supply is electrically connected with the base electrode of the NPN triode, the emitter electrode of the NPN triode is grounded, and the emitter electrode of the NPN triode is electrically connected with the grid electrode of the first PMOS tube through the fourth resistor; The collector of NPN triode is connected with one end of first resistance and second resistance respectively, the other end of first resistance is connected with the source of first PMOS pipe and the projecting pole electric connection of PNP triode respectively, the other end of second resistance is led to with the base electric connection of PNP triode, the collector of PNP triode is connected with the grid electric connection of first PMOS pipe.
3. The low noise power path management charging circuit of claim 1, wherein said charging power source comprises an ac transformer, a full bridge rectifier filter circuit, a linear regulated power supply connected to 220V mains; the alternating current transformer is electrically connected with the linear voltage-stabilized power supply through the full-bridge rectifying and filtering circuit, and the linear voltage-stabilized power supply is electrically connected with the electric equipment so as to be capable of directly supplying power to the electric equipment; The full-bridge rectifying and filtering circuit is electrically connected with the lithium battery through the lithium battery charging management circuit, and the full-bridge rectifying and filtering circuit is electrically connected with the power supply access detection unit.
4. A low noise power path management charging circuit according to claim 3, wherein said ac transformer is a 220V mains to 12V ac transformer; The full-bridge rectifying and filtering circuit is a rectifying circuit for converting 12V alternating current into 17V direct current; the linear stabilized power supply is a direct current transformer for converting 17V direct current into 12.6V direct current; the output power of the lithium battery is 12.6V.
5. The power supply system of the electric equipment is characterized by comprising a charging power supply, a lithium battery and the electric equipment; The charging power supply is electrically connected with the electric equipment; The lithium battery is electrically connected with the electric equipment through the low-noise power path management charging circuit according to any one of claims 1-4; the charging power supply is further electrically connected to the low noise power path management charging circuit of any one of claims 1-4.
6. The powered device power supply system as claimed in claim 5, wherein the charging power supply includes an ac transformer, a full-bridge rectifying and filtering circuit, and a linear regulated power supply connected to 220V mains supply; the alternating current transformer is electrically connected with the linear voltage-stabilized power supply through the full-bridge rectifying and filtering circuit, and the linear voltage-stabilized power supply is electrically connected with the electric equipment so as to be capable of directly supplying power to the electric equipment; The full-bridge rectifying and filtering circuit is electrically connected with the lithium battery through the lithium battery charging management circuit, and the full-bridge rectifying and filtering circuit is electrically connected with the power supply access detection unit.

Description

Low-noise power supply path management charging circuit and power supply system of electric equipment Technical Field The utility model relates to the field of equipment power supply, in particular to a low-noise power path management charging circuit and an electric equipment power supply system. Background When designing a device, it is common to design a built-in battery for portable or offline scenarios. Lithium batteries are often preferred for capacity, volume, popularity, and the like. Existing lithium battery charging uses its adapted charger for charging, and charging and discharging are usually performed through the same interface. The charger basically adopts the topology design of a switching power supply mainly comprising components such as an integrated control chip, a high-frequency transformer, a power switch tube and the like. The charging process of the lithium battery includes four stages of trickle charge (also called precharge), constant current charge, constant voltage charge, and charge termination. The constant-current charging stage has the largest current, the constant-voltage charging stage has the current which is gradually reduced from the largest value along with the continuous charging process according to the saturation degree of the battery core, and when the charging current is reduced to one percent of the constant-current charging current, the charging is considered to be terminated, the trickle charging is used for pre-charging (restorative charging) the fully discharged battery unit, and the trickle charging current is generally one tenth of the constant-current charging current. However, when the equipment using the lithium battery is used while charging, the noise of the power supply with a larger charger often affects the noise floor of the electric equipment and affects the equipment precision. When the lithium battery is in an overdischarge state, the lithium battery is directly connected with a charger, and the situation that the electric equipment with high starting current requirements cannot be started often occurs. The lithium battery warns the use situation of edge charging on the use proposal, and although the edge charging is safe in most cases, the problem of swelling, leakage, even spontaneous combustion and the like of the lithium battery can be caused with extremely low probability, and the consequences caused by the situations are mostly unacceptable. Disclosure of utility model The utility model aims to solve the problems in the prior art and provide a low-noise power path management charging circuit and a power supply system ‌ of electric equipment. The technical scheme is that the low-noise power path management charging circuit is used for switching on and off a lithium battery and electric equipment according to a charging power supply and comprises: the power supply is connected to the detection unit and the path switching-off unit; the power supply access detection unit is electrically connected with the path switching-off unit; The lithium battery is electrically connected with the electric equipment through the path switching-off unit; the power supply access detection unit is electrically connected with the charging power supply. Preferably, the path turn-off unit comprises a first PMOS tube and a second PMOS tube; The drain electrode of the first PMOS tube is electrically connected with the output end of the lithium battery, the source electrode of the first PMOS tube is electrically connected with the source electrode of the second PMOS tube, and the drain electrode of the second PMOS tube is electrically connected with the electric equipment; The source electrode of the first PMOS tube is electrically connected with the power supply access detection unit; The grid electrode of the first PMOS tube is electrically connected with the grid electrode of the second PMOS tube and then is electrically connected with the power supply access detection unit. Preferably, the power supply access detection unit comprises a PNP triode, an NPN triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; The charging power supply is grounded through a third resistor and a fifth resistor in sequence, one end, connected with the third resistor and the fourth resistor, of the charging power supply is electrically connected with the base electrode of the NPN triode, the emitter electrode of the NPN triode is grounded, and the emitter electrode of the NPN triode is electrically connected with the grid electrode of the first PMOS tube through the fourth resistor; The collector of NPN triode is connected with one end of first resistance and second resistance respectively, the other end of first resistance is connected with the source of first PMOS pipe and the projecting pole electric connection of PNP triode respectively, the other end of second resistance is led to with the base electric connection of PNP triode, the co