CN201821141U

CN201821141U - Charger device with direct current voltage reduction and conversion function

Info

Publication number: CN201821141U
Application number: CN2010205697230U
Authority: CN
Inventors: 李彬斌
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-10-18
Filing date: 2010-10-18
Publication date: 2011-05-04
Anticipated expiration: 2020-10-18

Abstract

The utility model relates to a charger device with direct current voltage reduction and conversion function, which comprises a basic voltage step-down circuit formed by an AP3003, a constant-current constant-voltage (CC/CV) circuit and a short-circuit protection circuit, wherein the basic voltage step-down circuit formed by the AP3003 adopts voltage divider resistors RA and RB to set an output voltage, the CC/CV circuit collects a sample of the current output from the resistors, the current sample is amplified by an operational amplifier AS358, the amplified signal is transmitted to the FB pin of the AP3003 through a diode, and the short-circuit protection circuit samples the output voltage through a transistor. The charger device achieves the accurate control of the output current by virtue of the CC/CV function, and the short-circuit protection circuit prevents the charger from burning out due to over-high input power in case of short circuit. The charger device provided by the utility model has a simple structure, is safe and reliable and improves the control accuracy.

Description

A kind of DC decompression convert charging apparatus

Technical field

The utility model relates to charger field, particularly relates to a kind of DC decompression convert charging apparatus.

Background technology

Along with the continuous development of electronic technology, mobile multimedia equipment becomes indispensable instrument in people's life just gradually, also more and more receives publicity with the corresponding charger design of these products.Use occasion according to charger, can be divided into domestic type charger and DC decompression electrical equipment, the charger majority that general mobile phone carries is a domestic type, it is ac-input type, DC decompression electrical equipment is the imported charger of a kind of direct current, its appearance makes the charging occasion variation more of mobile device, input voltage 12～the 36V of DC decompression electrical equipment, output voltage 5.1 ± 0.1V, output current 750 ± 50mA, charger is when charging the battery, if charging current is excessive, may cause battery heating, the life-span shortens even damage.

The utility model content

The purpose of this utility model provides a kind of simple in structure, and control accurately has the DC decompression convert charging apparatus of short-circuit protection circuit.

The technical scheme that the utility model adopted is such: a kind of DC decompression convert charging apparatus; comprise basic reduction voltage circuit, constant current constant voltage (CC/CV) circuit and short-circuit protection circuit that AP3003 makes up; the basic reduction voltage circuit that described AP3003 makes up adopts divider resistance RA and RB to set output voltage; the electric current of constant current constant voltage (CC/CV) circuit sampling resistance output; amplify through operational amplifier A S358; signal after the amplification is delivered to the FB pin of AP3003 by diode, and short-circuit protection circuit is by the transistor sampling and outputting voltage.

By adopting the aforementioned techniques scheme; the beneficial effects of the utility model are: this DC decompression convert charging apparatus adopts constant current constant voltage (CC/CV) function; realization is to the accurate control of output current; and short-circuit protection circuit has guaranteed that charger is because input power is excessive and burn during short circuit; simple in structure; safe and reliable, control accurately.

Description of drawings

Fig. 1 is the frame assumption diagram of the utility model embodiment;

Fig. 2 is the basic reduction voltage circuit figure that the AP3003 of the utility model embodiment makes up;

Fig. 3 is constant current constant voltage (CC/CV) circuit diagram of the utility model embodiment;

Fig. 4 is the short-circuit protection circuit figure of the utility model embodiment.

Embodiment

Further specify the utility model below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, a kind of DC decompression convert charging apparatus comprises basic reduction voltage circuit, constant current constant voltage (CC/CV) circuit and short-circuit protection circuit that AP3003 makes up.

As shown in Figure 2, the basic reduction voltage circuit that AP3003 makes up is the core of whole DC decompression electric system, it provides necessary voltage and current for battery in charging process, adopt divider resistance RA and RB to set output voltage, CFF electric capacity can increase the phase margin of loop, improve the stability of a system, span is 10～33nF.

As shown in Figure 3, constant current constant voltage (CC/CV) circuit is divided into two parts, a part is the constant current ring: the sampling resistor RS output current IO of sampling, amplify through operational amplifier A S358_1, multiplication factor is by R2/R1 decision (R1=R3, R2=R4), the signal after the amplification is delivered to the FB pin of AP3003 by diode D1; Another part is constant voltage ring: resistance R A and RB sampling and outputting voltage VO, and process AS358_2 and diode D2 deliver to the FB pin of AP3003.Wherein, VD1, VD2 are respectively the forward conduction voltage of diode D1 and D2, and VREF is the reference voltage of AP3003 inside.Can select suitable R s, R2, R1, RA, RB and diode according to designing requirement, obtaining constant current point is 750mA, and constant pressure point is the DC decompression electric system of 5V.

As shown in Figure 4, short-circuit protection circuit utilizes a transistor to come sampling and outputting voltage, judges whether to be short-circuited in the state variation before and after the short circuit according to output voltage, thereby realizes defencive function.Light-emitting diode in the circuit diagram lamp of giving instruction, after short circuit took place, light-emitting diode D3 lighted, eliminate short circuit after, restart power supply, circuit can recover operate as normal.After short circuit takes place; output voltage process resistance R A and RB sampling obtain magnitude of voltage and can't keep triode Q1 conducting; triode Q1 disconnects; capacitor C 1 is recharged; the voltage VEN of the EN pin of connection AP3003 As time goes on voltage constantly raises; in a single day voltage VEN is higher than the threshold voltage of EN pin, and whole system quits work, and has realized the function of short-circuit protection.

More than show and described basic principle of the present utility model and principal character and advantage thereof; the technical staff of the industry should understand; the utility model is not restricted to the described embodiments; that describes in the foregoing description and the explanation just illustrates principle of the present utility model; under the prerequisite that does not break away from the utility model spirit and scope; the utility model also has various changes and modifications; these changes and improvements all fall in claimed the utility model scope, and the claimed scope of the utility model is defined by appending claims and equivalent thereof.

Claims

1. DC decompression convert charging apparatus; it is characterized in that: comprise basic reduction voltage circuit, constant current constant voltage (CC/CV) circuit and short-circuit protection circuit that AP3003 makes up; the basic reduction voltage circuit that described AP3003 makes up adopts divider resistance RA and RB to set output voltage; the electric current of constant current constant voltage (CC/CV) circuit sampling resistance output; amplify through operational amplifier A S358; signal after the amplification is delivered to the FB pin of AP3003 by diode, and short-circuit protection circuit is by the transistor sampling and outputting voltage.