WO2014067436A1

WO2014067436A1 - Charging/discharging control circuit

Info

Publication number: WO2014067436A1
Application number: PCT/CN2013/086060
Authority: WO
Inventors: 冯汉春; 秦岭; 尹博; 戴翔
Original assignee: 恩力能源科技（南通）有限公司
Priority date: 2012-10-29
Filing date: 2013-10-28
Publication date: 2014-05-08
Also published as: CN202978313U

Abstract

A charging/discharging control circuit. The charging/discharging control circuit comprises a controller (21), a charging circuit, and a discharging circuit. The controller is provided with a first pulse-width modulation output end (211) and a second pulse-width modulation output end (212). The first pulse-width modulation output end is electrically connected to the charging circuit; the second pulse-width modulation output end is electrically connected to the discharging circuit. The controller, by adjusting the mark-to-space ratio of the output of the first pulse-width modulation output end, controls an electric current that flows from an external power source to the charging circuit, thus controlling a charging electric current, and, by adjusting the mark-to-space ratio of the output of the second pulse-width modulation output end, controls an electric current that flows from a battery module to the discharging circuit, thus controlling a discharging current. The charging/discharging control circuit is not only capable of switching between charging and discharging of a battery, but also capable of adjusting the magnitude of the charging current or of the discharging current via the output of the controller.

Description

TECHNICAL FIELD The present invention relates to the field of circuit technologies, and in particular, to a charge and discharge control circuit. Background technique

The battery module needs to be charged and discharged during use. When charging, the current of the external power source flows to the battery module. When discharging, the current of the battery module flows to the external power device. The charge and discharge control circuit currently applied to the battery module can only control the charging or discharging of the battery module, and cannot adjust the current of charging or discharging, and the use is not flexible enough. SUMMARY OF THE INVENTION Embodiments of the present invention provide a charge and discharge control circuit capable of adjusting a charging or discharging current to a battery module.

In order to solve the above technical problem, the embodiment of the present invention discloses the following technical solutions:

A charge and discharge control circuit includes a controller, a charging circuit and a discharging circuit, wherein the controller has a first pulse width modulation output end and a second pulse width modulation output end, and the first pulse width modulation output end The charging circuit is electrically connected, the second pulse width modulation output end is electrically connected to the discharging circuit; and the controller controls the external power source to flow by adjusting a duty ratio of the output of the first pulse width modulation output terminal to The current of the charging circuit controls the charging current, and controls the current flowing to the discharging circuit by the battery module by adjusting the duty ratio of the output of the second pulse width modulation output terminal to control the discharging current.

Further, in the charging circuit, a gate of the first transistor is electrically connected to a first pulse width modulation output end of the controller, a source thereof is electrically connected to the external power source, and a drain thereof and an end of the inductor are electrically connected Connected, the other end of the inductor is electrically connected to the cathode of the body diode of the second transistor, and the anode of the body diode of the second transistor is electrically connected to the battery module. Further, a drain of the first transistor is further electrically connected to an anode of the first freewheeling diode of the inductor, and a cathode of the first freewheeling diode is electrically connected to the battery module. Preferably, the first transistor is a gold oxide half field effect transistor MOSFET. Further, in the discharge circuit, a gate of the second transistor is electrically connected to a second pulse width modulation output end of the controller, and a source thereof is electrically connected to the battery module, and a drain and a drain thereof are One end of the inductor is electrically connected, and the other end of the inductor is electrically connected to a cathode of a body diode of the first transistor, and an anode of the body diode of the first transistor is electrically connected to an external power device.

Further, a drain of the second transistor is further electrically connected to an anode of the second freewheeling diode of the inductor, and a cathode of the second freewheeling diode is electrically connected to the external power device.

Preferably, the second transistor is a MOSFET. The charge and discharge control circuit in the embodiment of the present invention can not only switch the charging and discharging of the battery, but also can adjust the current of charging or discharging through the output of the controller. By controlling the charging and discharging currents, the charging and discharging time of the battery module can be adjusted, so that the user can better control the battery and increase the flexibility of use. DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below, and it will be apparent to those skilled in the art that In other words, other drawings can be obtained based on these drawings without paying creative labor. 1 is a schematic diagram of a charge and discharge control circuit of the present invention;

2 is a schematic diagram of another charge and discharge control circuit of the present invention. detailed description

The above described objects, features, and advantages of the embodiments of the present invention will become more apparent and understood. Give further details.

Referring to FIG. 1, a schematic diagram of a charge and discharge control circuit of the present invention is shown.

The control circuit can include a controller 11, a charging circuit 12, and a discharging circuit 13.

The controller 11 has a first PWM (Pulse Width Modulation) output 111 and a second PWM output 112. The first PWM output 111 is electrically connected to the charging circuit 12, and the second PWM output 112 and the discharging circuit 13 are provided. The controller 11 controls the current of the external power source to the charging circuit 12 by adjusting the duty ratio of the output of the first PWM output terminal 111 to control the charging current by adjusting the second PWM. The duty cycle outputted by the output terminal 112 controls the current flowing from the battery module to the discharge circuit 13 to control the discharge current. The controller 11 can be a control chip of a power management system in a battery, or other control chip with a PWM output. The charge and discharge control circuit in this embodiment can not only switch the charging and discharging of the battery, but also can adjust the magnitude of the current of charging or discharging through the controller output. By controlling the charging and discharging currents, the charging and discharging time of the battery module can be adjusted, so that the user can better control the battery and increase the flexibility of use. Referring to FIG. 2, it is a schematic diagram of another charge and discharge control circuit of the present invention.

The control circuit may include a controller 21, a charging circuit (indicated by a solid line in the drawing), and a discharging circuit (indicated by a broken line in the drawing).

In the charging circuit, the first PWM output terminal 211 of the controller 21 is electrically connected to the gate of the first transistor S1 221, the source of the first transistor S1 221 is electrically connected to an external power source, and the drain is electrically connected to the inductor L222. The other end of the inductor L222 is electrically connected to the cathode of the body diode 224 of the second transistor S2 223, and the anode of the body diode 224 is electrically connected to the battery module.

When charging, the first PWM output terminal 211 of the controller 21 outputs, the first transistor S1 221 is turned on, the second PWM output terminal 212 is not output, and the second transistor S2 223 is turned off, as indicated by the solid arrow in FIG. 2, the current The positive electrode from the external power source flows to the battery module, passes through the body diode 224 of the second transistor S2 223, the inductor L222, and the first transistor S1 221, and flows back to the negative terminal of the external power source. The controller 21 can control the current flowing through the first transistor S1 221 by adjusting the duty ratio of the output of the first PWM output terminal 211, thereby controlling the charging current.

In addition, the drain of the first transistor S1 221 is also electrically connected to the anode of the first freewheeling diode D1 225 of the inductor L222, and the cathode of the first freewheeling diode D1 225 is electrically connected to the battery module. When the current of the external power source suddenly becomes small, the inductor L222 can charge the battery module through a loop composed of the first freewheeling diode D1 225, the battery module and the body diode 224, and release the induced electromotive force generated on the inductor L222.

In the discharge circuit, the second PWM output 212 of the controller 21 is electrically connected to the gate of the second transistor S2 223, the source of the second transistor S2 223 is electrically connected to the battery module, and the drain and the end of the inductor L222 Electrically connected, the other end of the inductor L222 is electrically connected to the cathode of the body diode 226 of the first transistor S1 221, and the anode of the body diode 226 is electrically connected to an external electrical device, as shown in FIG.

When discharging, the second PWM output 212 of the controller 21 outputs, the second transistor S2 223 is turned on, the first PWM output terminal 211 is not output, and the first transistor S1 221 is turned off, as indicated by the dotted arrow in FIG. The current flows from the positive electrode of the battery module to the external power device, and passes through the body diode 226 of the first transistor S1 221, and the inductor L222 and the second transistor S2 223 flow back to the negative terminal of the battery module. The controller 21 can control the current flowing through the second transistor S2 223 by adjusting the duty ratio of the output of the second PWM output 212, thereby controlling the discharge current.

In addition, the drain of the second transistor S2 223 is also electrically connected to the anode of the second freewheeling diode D2 227 of the inductor L222, and the cathode of the second freewheeling diode D2 227 is electrically connected to the external consumer. When the current of the battery module suddenly becomes small, the inductor L222 can supply power to the external power device through a circuit composed of the second freewheeling diode D2 227, the external power device and the body diode 226, and release the induced electromotive force generated on the inductor L222. During the discharge process, when a short circuit occurs in the external electrical equipment, the current in the discharge circuit will rise rapidly. At this time, the inductor L222 can suppress the short-circuit current, and store the energy of the current in the inductor L222 to reduce the current. Mutation, taking protection measures for the system (such as turning off the first transistor S1 221 and the second transistor S2 223) to win time. When the system turns off the first transistor S1 221 and the second transistor S2 223, the energy of the inductor L222 can be discharged through the circuit composed of the second freewheeling diode D2 227 and the body diode 226 without damaging the inductor L222 itself. When it is necessary to disconnect the battery module and the external circuit (external power supply or external power supply device), the controller 21 only needs to control whether the first PWM output terminal 211 and the second PWM output terminal 212 are not output, then the first transistor S1 221 And the second transistor S2 223 is turned off, and the battery module and the external circuit are disconnected.

The first transistor S1 221 and the second transistor S2 223 may each be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). The MOSFET's turn-on and turn-off can be used to control the operation and disconnection of the circuit in which it is located. The first transistor S1 221 is used to control the charging circuit, and the second transistor S2 223 is used to control the discharging circuit. The opening and closing of the two transistors are controlled by the two PWM outputs of the controller 21, respectively. The charge and discharge control circuit in this embodiment can not only switch the charging and discharging of the battery, but also adjust the current of charging or discharging through the controller output, and can adjust the charging and discharging of the battery module by controlling the charging and discharging currents. Time allows the user to better control the battery and increase the flexibility of use. Moreover, the battery can be protected by completely disconnecting the battery from the external circuit through two MOSFET tubes. The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

Rights request

A charge and discharge control circuit, comprising: a controller, a charging circuit and a discharging circuit, wherein the controller has a first pulse width modulation output end and a second pulse width modulation output end, the first a pulse width modulation output terminal electrically connected to the charging circuit, the second pulse width modulation output terminal being electrically connected to the discharge circuit; the controller adjusting a duty ratio of the output of the first pulse width modulation output terminal Controlling a current flow from the external power source to the charging circuit to control a charging current, and controlling a current flowing from the battery module to the discharging circuit by adjusting a duty ratio of the output of the second pulse width modulation output terminal to control the discharging Current.

2. The charge and discharge control circuit according to claim 1, wherein in the charging circuit, a gate of the first transistor is electrically connected to a first pulse width modulation output end of the controller, and a source thereof Electrically connected to the external power source, the drain thereof is electrically connected to one end of the inductor, the other end of the inductor is electrically connected to the cathode of the body diode of the second transistor, the anode of the body diode of the second transistor and the battery The module is electrically connected.

3. The charge and discharge control circuit according to claim 2, wherein a drain of the first transistor is further electrically connected to an anode of the first freewheeling diode of the inductor, and the first freewheeling diode The cathode is electrically connected to the battery module.

4. The charge and discharge control circuit according to claim 2, wherein the first transistor is a MOS field effect transistor MOSFET.

5. The charge and discharge control circuit according to claim 2, wherein in the discharge circuit, a gate of the second transistor is electrically connected to a second pulse width modulation output end of the controller, The source is electrically connected to the battery module, the drain thereof is electrically connected to one end of the inductor, and the other end of the inductor is electrically connected to the cathode of the body diode of the first transistor, the body of the first transistor The anode of the diode is electrically connected to an external electrical device.

6. The charge and discharge control circuit according to claim 5, wherein a drain of the second transistor is further electrically connected to an anode of the second freewheeling diode of the inductor, and the second freewheeling diode The cathode is electrically connected to the external electrical device.

7. The charge and discharge control circuit according to claim 6, wherein the second transistor is a MOSFET.