CN206807035U

CN206807035U - A onboard charger short-circuit protection improves circuit

Info

Publication number: CN206807035U
Application number: CN201720190950.4U
Authority: CN
Inventors: 谭青龙; 曹凯
Original assignee: Dongguan City Hu Electronic Technology Co Ltd
Current assignee: Dongguan City Hu Electronic Technology Co Ltd
Priority date: 2017-03-01
Filing date: 2017-03-01
Publication date: 2017-12-26
Anticipated expiration: 2027-03-01

Abstract

The utility model discloses a onboard charger short-circuit protection to improve circuit, including circuit board, chip U1 is welded with circuit board, chip U1 pin 1 is connected with electric capacity C3, and the electric capacity C3 other end is connected with inductance L1, and the inductance L1 other end is connected with inductance L2, diode D1 negative pole, electric capacity C4 and chip U1 pin 6, the electric capacity C4 other end is connected with resistance R4, and the resistance R4 other end is connected with diode D1 positive pole, electric capacity C5 and transformer T1 secondary coil L4, the transformer T1 secondary coil L4 other ends are connected with diode Z2 positive pole, electric capacity C6 and grounding ports GND, the electric capacity C6 other end is connected with voltage output port Vout, diode Z2 negative pole and transformer T1 primary coil L3.The utility model uses diode, electric capacity and resistive element so that cost is relatively low, and solves the chip U1 overheats caused by continuing output short-circuit failure, avoids whole onboard charger and is damaged.

Description

A onboard charger short-circuit protection improves circuit

Technical field

Onboard charger technical field is the utility model is related to, more particularly to a onboard charger short-circuit protection improves electricity Road.

Background technology

At present, known onboard charger integrated circuit short-circuit protection scheme use output short-circuit state under enter beat every Pattern (constantly restarts integrated circuit) when output short-circuit.Although short defencive function can be realized, when product is repeatedly short in output end The too high drawback of Integrated Circuit Temperature can be caused under the environment of road, whole onboard charger is in turn resulted in and is damaged.

Utility model content

The purpose of this utility model is and a onboard charger proposed in order to solve shortcoming present in prior art Short-circuit protection improves circuit.

To achieve these goals, the utility model employs following technical scheme：

A onboard charger short-circuit protection improves circuit, including circuit board, and chip U1, institute are welded with the circuit board The pin 1 for stating chip U1 is connected with electric capacity C3, and the electric capacity C3 other end is connected with inductance L1, and inductance L1 other end connection There are inductance L2, diode D1 negative pole, electric capacity C4 and chip U1 pin 6, the other end of the electric capacity C4 is connected with resistance R4, And the resistance R4 other end is connected with the secondary coil L4 of diode D1 positive pole, electric capacity C5 and transformer T1, the transformer The T1 secondary coil L4 other ends are connected with diode Z2 positive pole, electric capacity C6 and grounding ports GND, and the electric capacity C6's is another End is connected with voltage output port Vout, diode Z2 negative pole and transformer T1 primary coil L3, and transformer T1's is first The level coil L3 other end is connected with the electric capacity C5 other end and the inductance L2 other end respectively, the pin 2 of the chip U1 Ground connection, and chip U1 pin 5 is connected with electric capacity C2 and resistance R1, the electric capacity C2 other end are connected with chip U1 pin 4th, resistance R3, diode D2 negative pole and NPN type triode Q1 colelctor electrode, the emitter stage connection of the NPN type triode Q1 There are resistance the R3 other end and electric capacity C7, and NPN type triode Q1 grounded emitter, the base stage of the NPN type triode Q1 Diode Z3 positive pole and NPN type triode Q1 emitter stage are connected with, the negative pole of the diode Z3 is connected with resistance R2, electricity Hinder the R1 other end, electric capacity the C7 other end and voltage output port Vout, the other end of the resistance R2 and diode D2's Positive pole is connected.

Preferably, the pin 5 of the chip U1 is also associated with electric capacity C1 and diode Z1 negative pole, and electric capacity C1's is another End is connected with diode Z1 positive pole.

Preferably, the pin 3 of the chip U1 is connected with resistance R5 and resistance R6, and the other end of the resistance R5 is connected with The negative pole of LED 1, and resistance R5 other end ground connection, the positive pole of the LED 1 are connected with resistance R7, the other end of the resistance R7 are connected with the resistance R6 other end and transformer T1 primary coil the L3 other end.

Preferably, the diode Z1, diode Z2 and diode Z3 are voltage-regulator diode.

Preferably, the chip U1 is IC chip, and chip U1 model MP2359.

Preferably, the resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, resistance R6 and resistance R7 resistance according to Secondary is 22000 ohm, 10000 ohm, 22000 ohm, 100 ohm, 9100 ohm, 2200 ohm, 47800 ohm.

Preferably, the electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6 and electric capacity C7 capacitance according to Secondary is 220nF, 220nF, 103uF, 470pF, 10uF, 104uF, 104uF.

In the utility model, a onboard charger short-circuit protection improves in circuit using on chip U1 pin 4 Voltage when being more than 1.2 volts, chip U1 is operated, during 1.2 volts of the voltage small fish on chip U1 pin 4, chip U1 not works Change chip U1 protection feature as feature, when electric capacity C2 obtains the voltage charging on chip U1 pins 4 for the first time, now Chip U1 obtains input voltage value more than 1.2 volts, and chip U1 carries out normal work, and now electric capacity C2 chargings will be once equivalent to afterwards Open-circuit condition, when chip U1 output short-circuit, it is equivalent to diode D2 positive pole and resistance R2 being connected on ground, that More than 1.2V voltage will now be cannot get on chip U1 pin 4, chip U1 will be turned off, so as to make chip U1 no longer heavy Open, the chip U1 caused by continuing output short-circuit failure no longer occurs and overheats, in turn results in the damage of whole onboard charger, this Utility model uses diode, electric capacity and resistive element so that cost is relatively low, and solves and cause because continuing output short-circuit failure Chip U1 overheat, avoid whole onboard charger and be damaged.

Brief description of the drawings

Fig. 1 be the utility model proposes a onboard charger short-circuit protection improve circuit fundamental diagram.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, the technical scheme in the embodiment of the utility model is carried out Clearly and completely describing, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole Embodiment.

Reference picture 1, a onboard charger short-circuit protection improve circuit, including circuit board, chip are welded with circuit board U1, chip U1 pin 1 are connected with electric capacity C3, and the electric capacity C3 other end is connected with inductance L1, and the inductance L1 other end connects Inductance L2, diode D1 negative pole, electric capacity C4 and chip U1 pin 6 are connected to, the electric capacity C4 other end is connected with resistance R4, and The resistance R4 other end is connected with the secondary coil L4 of diode D1 positive pole, electric capacity C5 and transformer T1, transformer T1 time The level coil L4 other ends are connected with diode Z2 positive pole, electric capacity C6 and grounding ports GND, and the electric capacity C6 other end is connected with electricity Pressure output port Vout, diode Z2 negative pole and transformer T1 primary coil L3, and transformer T1 primary coil L3 The other end is connected with the electric capacity C5 other end and the inductance L2 other end respectively, and chip U1 pin 2 is grounded, and chip U1 Pin 5 is connected with electric capacity C2 and resistance R1, and the electric capacity C2 other end is connected with chip U1 pin 4, resistance R3, diode D2 The colelctor electrode of negative pole and NPN type triode Q1, NPN type triode Q1 emitter stage are connected with resistance the R3 other end and electric capacity C7, and NPN type triode Q1 grounded emitter, NPN type triode Q1 base stage are connected with diode Z3 positive pole and NPN type Triode Q1 emitter stage, diode Z3 negative pole are connected with resistance R2, the resistance R1 other end, electric capacity the C7 other end and electricity Output port Vout is pressed, the resistance R2 other end is connected with diode D2 positive pole, and chip U1 pin 5 is also associated with electric capacity C1 and diode Z1 negative pole, and the electric capacity C1 other end is connected with diode Z1 positive pole, chip U1 pin 3 is connected with Resistance R5 and resistance R6, the resistance R5 other end are connected with the negative pole of LED 1, and resistance R5 other end ground connection, The positive pole of LED 1 is connected with resistance R7, and the resistance R7 other end is connected with resistance the R6 other end and transformer T1 Primary coil L3 the other end, diode Z1, diode Z2 and diode Z3 are voltage-regulator diode, and chip U1 is integrated electricity Road chip, and chip U1 model MP2359, resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, resistance R6 and resistance R7 resistance is followed successively by 22000 ohm, 10000 ohm, 22000 ohm, 100 ohm, 9100 ohm, 2200 ohm, 47800 Europe Nurse, electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6 and electric capacity C7 capacitance be followed successively by 220nF, 220nF, 103uF、470pF、10uF、104uF、104uF。

In the utility model, when being more than 1.2 volts using the voltage on chip U1 pin 4, chip U1 is operated, chip During 1.2 volts of the voltage small fish on U1 pin 4, work characteristics does not change chip U1 protection feature to chip U1, as electric capacity C2 When obtaining the voltage charging on chip U1 pins 4 for the first time, electric capacity C2 can be in the of short duration short-circuit condition of charging transient, now chip U1 Input voltage value is obtained more than 1.2 volts, so it is 5V voltages that chip U1 work outputs are normal, electric capacity C2 chargings once afterwards will be equivalent Pin 4 for open-circuit condition now chip U1 obtains output voltage more than 1.2 volts by resistance R2 and diode D2, chip U1 continuous firings is equivalent to diode D2 positive pole and resistance R2 being connected on ground when chip U1 output short-circuit, It so will now cannot get more than 1.2V voltage on chip U1 pin 4, chip U1 will be turned off, so as to make chip U1 no longer heavy Open, the chip U1 caused by continuing output short-circuit failure no longer occurs and overheats, in turn results in the damage of whole onboard charger.

It is described above, the only preferable embodiment of the utility model, but the scope of protection of the utility model is not This is confined to, any one skilled in the art is in the technical scope that the utility model discloses, according to this practicality New technical scheme and its utility model design are subject to equivalent substitution or change, should all cover in protection model of the present utility model Within enclosing.

Claims

1. a onboard charger short-circuit protection improves circuit, including circuit board, chip U1 is welded with the circuit board, it is special Sign is, the pin 1 of the chip U1 is connected with electric capacity C3, and the electric capacity C3 other end is connected with inductance L1, and inductance L1 The other end is connected with inductance L2, diode D1 negative pole, electric capacity C4 and chip U1 pin 6, and the other end of the electric capacity C4 connects Resistance R4 is connected to, and the resistance R4 other end is connected with the secondary coil L4 of diode D1 positive pole, electric capacity C5 and transformer T1, The secondary coil L4 other ends of the transformer T1 are connected with diode Z2 positive pole, electric capacity C6 and grounding ports GND, the electricity The other end for holding C6 is connected with voltage output port Vout, diode Z2 negative pole and transformer T1 primary coil L3, and becomes The depressor T1 primary coil L3 other end is connected with the electric capacity C5 other end and the inductance L2 other end respectively, the chip U1 pin 2 is grounded, and chip U1 pin 5 is connected with electric capacity C2 and resistance R1, and the other end of the electric capacity C2 is connected with core Piece U1 pin 4, resistance R3, diode D2 negative pole and NPN type triode Q1 colelctor electrode, the NPN type triode Q1's Emitter stage is connected with the resistance R3 other end and electric capacity C7, and NPN type triode Q1 grounded emitter, the pole of NPN type three Pipe Q1 base stage is connected with diode Z3 positive pole and NPN type triode Q1 emitter stage, the negative pole connection of the diode Z3 Have resistance R2, the resistance R1 other end, the electric capacity C7 other end and a voltage output port Vout, the other end of the resistance R2 and Diode D2 positive pole is connected.

2. a onboard charger short-circuit protection according to claim 1 improves circuit, it is characterised in that the chip U1 Pin 5 be also associated with electric capacity C1 and diode Z1 negative pole, and the electric capacity C1 other end is connected with diode Z1 positive pole.

3. a onboard charger short-circuit protection according to claim 1 improves circuit, it is characterised in that the chip U1 Pin 3 be connected with resistance R5 and resistance R6, the resistance R5 other end and be connected with the negative pole of LED 1, and electricity R5 other end ground connection is hindered, the positive pole of the LED 1 is connected with resistance R7, the resistance R7 other end connection There are the resistance R6 other end and transformer T1 primary coil the L3 other end.

4. a onboard charger short-circuit protection according to claim 1 improves circuit, it is characterised in that the diode Z1, diode Z2 and diode Z3 are voltage-regulator diode.

5. a onboard charger short-circuit protection according to claim 1 improves circuit, it is characterised in that the chip U1 For IC chip, and chip U1 model MP2359.

6. a onboard charger short-circuit protection according to claim 1 improves circuit, it is characterised in that the resistance R1, resistance R2, resistance R3, resistance R4, resistance R5, resistance R6 and resistance R7 resistance be followed successively by 22000 ohm, 10000 ohm, 22000 ohm, 100 ohm, 9100 ohm, 2200 ohm, 47800 ohm.

7. a onboard charger short-circuit protection according to claim 2 improves circuit, it is characterised in that the electric capacity C1, electric capacity C2, electric capacity C3, electric capacity C4, electric capacity C5, electric capacity C6 and electric capacity C7 capacitance be followed successively by 220nF, 220nF, 103uF, 470pF、10uF、104uF、104uF。