CN105811479A - Device and method for determining device charging saturation - Google Patents

Abstract

The present application discloses a device and method for judging that a device is fully charged. The method for judging the charging saturation of the device includes: detecting the electrical parameter when the device to be charged is charged; switching between the light load charging circuit and the heavy load charging circuit according to the magnitude of the electrical parameter and according to the magnitude of the change rate of the electrical parameter Determine whether the charge is saturated. This embodiment avoids the waste of electric power during charging.

Description

Device and method for judging device charging saturation

technical field

The present application relates to the field of charging, in particular to the technical field of judging that a device is fully charged, and in particular to an apparatus and method for judging that a device is fully charged.

Background technique

As various portable devices such as mobile phones, tablet computers, cameras, etc. are more and more widely used, the demand for power supply devices or backup power devices for charging the batteries of these portable devices is also increasing. When charging, traditional power supply equipment only continuously outputs charging current to the battery of the equipment to be charged, but cannot determine whether the battery of the equipment to be charged is in a state of saturation. In this case, the power supply device may stop charging when the battery of the device is not fully charged, or may still output current when the battery of the device is fully charged, which causes a great waste of power for the power supply device. It also adversely affects the battery life of the charging device after multiple uses.

Some improved versions of the power supply equipment have the function of detecting the output current, but due to the accuracy of the analog-to-digital conversion of the microprocessor, the deviation of the offset voltage, and the fact that the resistance of the detection resistor is too large to affect the efficiency, the detection of the output current of this type of power supply equipment is limited. .

For power supply equipment with better functions, the method of adding a high-precision differential amplifier is adopted to solve the problem of the accuracy of the analog-to-digital conversion of the microprocessor and the problem of limited detection output current caused by the small resistance of the detection resistor. For example, in the known technology, the The detection resistor is enlarged by 50 times, but this not only increases the cost of the power supply equipment, but also brings other problems, such as electrostatic discharge, which makes the development of the power supply equipment more difficult.

Contents of the invention

Aiming at the above-mentioned problems in the prior art, the present application provides a control device and method for charging power supply equipment that can at least partially improve the above-mentioned defects in the prior art.

On the one hand, the present application provides a device for judging that a device is fully charged. The device includes: a detection unit for detecting electrical parameters of the device to be charged; a switching unit for providing a light-load charging circuit and a heavy-load charging circuit. The circuit is controlled by the control unit to switch between the two circuits; the control unit is used to control the switching unit and judge whether the charging is saturated according to the magnitude of the electrical parameter detected by the detection unit.

In some embodiments, the control unit further includes: a light load judging unit, configured to judge whether the device to be charged is in a light load working state according to the relationship between the electrical parameter and a preset light load threshold.

In some embodiments, the control unit is further configured to: send a signal to the switching unit to switch to a heavy-load charging circuit in response to the light-load judging unit judging that the device to be charged is not in a light-load working state; The load judging unit judges that the device to be charged is in a light-load working state, and sends a signal to the switching unit to switch to a light-load charging circuit.

In some embodiments, the control unit further includes: a saturation judging unit, configured to judge whether the charging is saturated according to the relationship between the electrical parameter and a preset saturation threshold.

In some embodiments, the control unit is further configured to: periodically send a signal to switch to the light-load charging circuit in response to the light-load judging unit judging that the device to be charged is in a light-load working state, And judge whether the charging is saturated through the saturation judging unit; in response to judging that the charging is not saturated, send a signal to the switching unit to switch to the heavy-load charging circuit; and in response to judging that the charging is saturated, send an indication of charging saturation to the user information and/or send a control signal to the device to be charged so that it stops outputting charging current.

In some embodiments, the electrical parameters include current, wherein if the current is less than a preset light load threshold, it is judged that the device to be charged is in a light load working state, otherwise, it is in a heavy load working state; when the current When it is less than the preset light load threshold, if the current is greater than the preset saturation threshold, it is judged that the charging is not saturated, otherwise, it is judged that the charging is saturated.

In some embodiments, the heavy load charging circuit is implemented by a first switch; and the light load circuit is implemented by a second switch.

In some embodiments, the first switch comprises a low impedance controllable electronic switch.

In a second aspect, the present application provides a method for judging that a device is fully charged. The method includes: detecting the electrical parameters of the device to be charged; Switch between charging circuits and judge whether the charging is saturated.

In some implementations, the above method further includes: judging whether the device to be charged is in a light load working state according to a relationship between the electrical parameter and a preset light load threshold.

In some embodiments, the above method further includes: switching to the heavy load charging circuit in response to judging that the device to be charged is not in a light load working state; in response to judging that the device to be charged is in a light load working state, switch for the light load charging circuit.

In some implementations, the above method further includes: judging whether charging is saturated according to the relationship between the electrical parameter and a preset saturation threshold.

In some embodiments, the above method further includes: in response to judging that the device to be charged is in a light-load working state, periodically switching to the light-load charging circuit, and judging whether the charging is saturated; in response to judging that the charging is not saturated , switching to the heavy load charging circuit; and in response to judging that the charging is saturated, sending an indication message of charging saturation to the user and/or sending a control signal to the device to be charged so that it stops outputting charging current.

The device and method for judging the charging saturation of the device provided by the present application can realize the detection of the charging saturation of the charging device through simple circuit and switch control, so as to avoid outputting current when the charging device is saturated, and avoid the waste of power. Due to timely disconnection, avoiding overcharging can also prolong the battery life of the device to be charged to a certain extent.

Description of drawings

Other characteristics, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

FIG. 1 is a schematic structural diagram of an embodiment of a device for judging device charging saturation in the present application;

FIG. 2 is a schematic structural diagram of another embodiment of the device for judging that the device is fully charged in the present application;

Fig. 3 is an internal implementation logic flow chart of an embodiment of the device for judging device charging saturation in the present application;

FIG. 4 is a partial circuit diagram of an embodiment of a device for judging device charging saturation in the present application;

Fig. 5 is a flowchart of an embodiment of a method for judging that a device is fully charged according to the present application.

detailed description

The application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain related inventions, rather than to limit the invention. It should also be noted that, for the convenience of description, only the parts related to the related invention are shown in the drawings.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

Please refer to FIG. 1 , which exemplarily shows a schematic structural view of an implementation of an apparatus for judging that a device is fully charged according to the present application.

As shown in FIG. 1 , an apparatus 100 for judging that a device is fully charged includes a detection unit 110 , a switching unit 120 , and a control unit 130 .

The detection unit 110 is used to detect electrical parameters when the device to be charged is charged. The switching unit 120 is used to provide a light-load charging circuit and a heavy-load charging circuit and is controlled by the control unit 130 to switch between the two circuits; the control unit 130 is used to control according to the magnitude of the electrical parameter detected by the detection unit Switch unit 120 and determine whether the charging is saturated. Wherein, whether the charging is saturated can be judged according to the rate of change of the electrical parameter. Further optionally, since the rate of change of the electrical parameters is relatively small when the device is fully charged, a rate-of-change judging unit may be set to determine that the rate of change is less than a certain threshold, and determine that the charge is saturated.

In some embodiments, the electrical parameters of the device to be charged include, but are not limited to, charging current, voltage across the device to be charged, and electric power.

In some embodiments, the two charging circuits provided by the switching unit 120: the light-load charging circuit and the heavy-load charging circuit can be realized by using two ordinary switches, or can be realized by using a single-pole double-throw switch. no limit. The switching unit is controlled by the control unit 130 to switch between the two charging circuits.

In some embodiments, the control unit 130 may be, for example, a processor. After the control unit 130 receives the electrical parameter detected by the detection unit 110, it judges the magnitude of the electrical parameter, and then sends a switching signal to the switching unit 120, so that the switching unit 120 switches between the light-load charging circuit and the heavy-load charging circuit. The control unit 130 can also judge whether the charging is saturated according to the magnitude of the electrical parameter detected by the detection unit 110 , and judge that the charging is saturated when the electrical parameter detected by the detection unit 110 reaches a certain threshold. Optionally, after judging that the charge is saturated, the user can be prompted, or a signal of charge saturation can be sent to the user, for example, the color of the charging indicator changes, or the power supply can be directly disconnected to stop charging. This application has no limitation in this regard.

Please refer to FIG. 2 , which exemplarily shows a schematic structural diagram of another embodiment of an apparatus for judging that a device is fully charged according to the present application.

As shown in FIG. 2 , the apparatus 100 for judging that a device is fully charged includes a detection unit 110 , a switching unit 120 , and a control unit 130 . In this embodiment, the detection unit 110 may include a first detection unit 111 and a second detection unit 112, the switching unit 120 may include a first switch 121 and a second switch 122, the control unit 130 may include a light load judgment unit 131 and a saturation Judgment unit 132.

In this embodiment, the detection unit 110 is used to detect electrical parameters of the device to be charged when it is being charged. The switching unit 120 is used to provide a light load charging circuit and a heavy load charging circuit, and is controlled by the control unit to switch between the two circuits. The control unit 130 is used for controlling the switching unit 120 and judging whether the charging is saturated according to the magnitude of the electrical parameter detected by the detection unit 110 .

Wherein, the control unit 130 further includes: a light load judging unit 131, configured to judge whether the device to be charged is in a light load working state according to the relationship between the electrical parameter and the preset light load threshold. In response to the light load judging unit 131 judging that the device to be charged is not in the light load working state, the control unit 130 sends a signal to the switching unit 120 to switch to a heavy load charging circuit; in response to the light load judging unit judging that the device to be charged is in the light load working state , the control unit 130 sends a signal to the switching unit 120 to switch to the light load charging circuit.

In addition, the control unit 130 further includes: a saturation judging unit 132, configured to judge whether the charging is saturated according to the relationship between the electric parameter and the preset saturation threshold. In response to the light load judging unit judging that the device to be charged is in a light load working state, the control unit 130 periodically sends a signal to the switching unit 120 to switch to the light load charging circuit, and judges whether the charging is saturated through the saturation judging unit; In response to judging that the charging is not saturated, the control unit 130 sends a signal to the switching unit 120 to switch to the heavy-load charging circuit; The device to be charged sends a control signal to make it stop outputting charging current.

In some embodiments, the heavy load charging circuit can be realized by the first switch 121 ; and the light load circuit can be realized by the second switch 122 . The first switch 121 may eg be a low impedance controllable electronic switch.

In some optional implementation manners, the detection unit includes a first detection unit 111 and a second detection unit 112, wherein both the first detection unit 111 and the second detection unit 112 may be current detection units. Wherein, the first detection unit 111 can be connected with the light load judging unit 131, and is used for detecting the magnitude of the charging current when it is in the heavy load charging circuit, and the light load judging unit 131 is used for judging whether the charging current detected by the first detecting unit 111 is greater than light load threshold. When it is judged to be greater than or equal to the light load threshold, it is judged to be in the heavy load working state, and the control unit 130 sends a switching signal to the switching unit to switch to the heavy load charging circuit or remain in the heavy load charging circuit, wherein the heavy load charging circuit can be controlled by The first switch 121 is realized. When it is judged to be less than the light load threshold, it is judged to be in the light load working state, and the control unit 130 sends a switching signal to the switching unit to switch to the light load charging circuit, wherein the light load charging circuit can be realized by the second switch 122 . When switching to the light load working state, the second detection unit 112 detects the magnitude of the charging current. Wherein, the second detection unit 112 can be connected with the saturation judging unit 132 for detecting the magnitude of the charging current, and the saturation judging unit 132 judges whether the charging current reaches the saturation threshold. When it is determined that the charging current is less than or equal to the saturation threshold, it is determined that the charging is saturated, and the control unit 130 controls to cut off the power supply or send a prompt or signal to the user. When it is judged that the charging current is greater than the saturation threshold, it is judged that the charging is not saturated, and the control unit 130 controls the switching unit 120 to switch to the heavy load charging circuit, such as the first switch 121, wherein the control unit 130 is also used to control the switching unit 120 cycle To switch to the light load charging circuit, the switching method can be, for example, pulse switching.

In other optional implementation manners, only the first detection unit 111 may be included, which is used to detect the magnitude of the current of the entire charging circuit or the magnitude of the voltage at both ends of the device to be charged. The relationship between the current or voltage and the corresponding threshold is judged by the light load judging unit and the saturation judging unit, and the control unit 130 controls the switching unit 120 to switch between the light load charging circuit and the heavy load charging circuit according to the judging result. Wherein, when the detection unit 110 is used to detect the voltage at both ends of the device to be charged, when the voltage exceeds the light load threshold, the light load judging unit 131 judges that it is in a light load working state, and the control unit 130 controls the switching unit 120 to switch to light load charging The circuit is realized by the second switch 122, for example. When it is judged that the voltage is less than the saturation threshold, the saturation judging unit 132 judges that the charging is saturated, and the control unit 130 controls the switching unit 120 to switch to the heavy load charging circuit, for example, realized by the first switch 121, and then the control unit 130 is also used to control the switching unit 120 Periodically switch to the light load charging circuit, the switching method can be, for example, pulse switching. When it is judged that the voltage is greater than or equal to the saturation threshold, it is judged that the charging is saturated, and the control unit 130 controls to cut off the power supply or send a prompt or signal to the user.

In other optional implementations, the first detection unit 111 may be a voltage detection unit for detecting the voltage across the device to be charged, and the second detection unit 112 is a current detection unit for detecting the magnitude of the charging current. The light load judging unit 131 can first judge whether the voltage is greater than or equal to the light load judging threshold, and if it is lower, then keep or switch to the heavy load charging circuit; otherwise, switch to the light load charging circuit. Then the saturation judging unit 132 judges whether the current is less than or equal to the saturation threshold, if it is greater than the saturation threshold, then switches to the heavy load charging circuit, and is controlled by the control unit 130 to periodically switch back to the light load charging circuit; otherwise, it is judged to be saturated, It is controlled by the control unit 130 to turn off the power supply or send a prompt or signal to the user.

Further refer to FIG. 3 , which exemplarily shows an internal implementation logic flow chart of an implementation of an apparatus for judging that a device is fully charged according to the present application.

In this embodiment, the device to be charged may be a lithium battery or a charging device containing a lithium battery, such as a mobile power supply or an electronic product.

According to the charging characteristics of lithium-ion batteries or lithium polymer batteries, the charging current in the charging process must first go through the constant current stage. In the constant current phase, the current is constant and the voltage increases rapidly. After the constant current stage is the constant voltage stage. In the constant voltage stage, as the voltage of the device to be charged increases, the charging current will decrease.

According to the above characteristics, the following logic flow can be used to control the device to be charged.

First, in step 301, start charging. Generally, the battery will be charged only when the battery power is low, so in step 302, the default is the heavy load charging circuit. Of course, if the battery is charged when the battery is fully charged, the subsequent judgment will also switch to the light load charging circuit.

In step 302, the heavy load charges the circuit. Provide a heavy-duty charging circuit for the device to be charged. For example, when the heavy-load charging circuit and the light-load charging circuit are controlled by the first switch and the second switch, when the charging power supply starts to supply power, the first switch is first turned on, and the second switch is turned off.

In step 303, the light load judgment unit determines whether the charging current Ix detected by the detection unit is smaller than a preset light load threshold I ₁ , that is, determines whether the load is in a light load working state. When the device to be charged is in a heavy load working state, the sink current is relatively large, and the light load threshold I ₁ can be set as a fixed value current threshold, for example, 200mA. If the current current Ix< _I1 , it is judged that the load is in a light-load working state, and step 304 is executed; otherwise, step 302 is executed.

In step 304, the light load judging unit can further determine whether the current charging current _Ix is less than a preset light load threshold _I1 within the pulse period _t1 to judge whether the device to be charged is in a light load working state. Optionally, t ₁ may be, for example, 1 second. If the current time is less than the pulse period t ₁ , execute step 302 to maintain the heavy load charging circuit, otherwise execute step 305 to switch to the light load charging circuit.

In step 305, the first switch is turned off and the second switch is turned on to provide a light-load charging circuit for the device to be charged.

In step 306, the light load judging unit determines whether the current charging current Ix detected by the detecting unit is smaller than a preset saturation threshold I ₂ , that is, determines whether the device to be charged is saturated or connected to a power supply device. When the device to be charged absorbs very little current when it is saturated or not connected, the saturation threshold I ₂ can be set as a fixed current threshold, for example, 10mA. If the current current Ix< _I2 , it is judged that the device to be charged is saturated or disconnected from the power supply device, and step 307 is performed to send an indication message of charging saturation to the user, or send an indication message of no load to the user, or send a message to the user The device to be charged sends a control signal to make it stop outputting the charging current. Otherwise, execute step 302 .

In some optional embodiments, the detection unit periodically detects the magnitude of the charging current, and the detection period may be, for example, 10 ms. The detection unit may be composed of, for example, milliohm level precision resistors.

In some optional embodiments, the light load threshold for the device to be charged working in the light load working state may be, for example, 100mA, and the saturation threshold may be, for example, 5mA. The light load threshold and saturation threshold can also be determined according to the battery capacity of the device to be charged. For example, the light load threshold can be set to 0.1C, and the saturation threshold can be set to 0.01C, where C represents the battery capacity. For example, if the battery capacity is 1000mAh, the light load threshold can be set to 100mA, and the saturation threshold can be set to 10mA. If the battery capacity is 3700mAh, the light load threshold can be set to 370mA, and the saturation threshold can be set to 37mA.

In other optional embodiments, the control unit may be, for example, a processor, and the light load is switched to a pulse mode, the period may be, for example, 1 second, and the pulse time may be, for example, 2 milliseconds. For a general processor, 2 milliseconds is enough to ensure that the processor detects the charging current and makes a judgment. The rest of the time 998 milliseconds is still a heavy load charging circuit. Since the light-load charging circuit only accounts for 2/1000 of the entire cycle, the efficiency will not be affected by working in the light-load charging circuit for a long time, and the light-load and charging saturation can be accurately detected. The instruction information sent to the user may be sound or other optically visible information, for example.

Further referring to FIG. 4 , it shows a partial circuit diagram of an embodiment of an apparatus for judging that a device is fully charged according to the present application.

As shown in Figure 4, the load is the device to be charged. The switching unit 120 may have two branches, and may form two loops for detecting different loads with the first detection unit 111 and the second detection unit 112 . Wherein, the first switch 121 and the first detection unit 111 can form a loop for heavy load detection, and the second switch 122, the second detection unit 112 and the first detection unit 111 can form a loop for pulse detection of light load . The switching unit includes a first switch 121 , a second switch 122 , a first detection unit 111 , and a second detection unit 112 connected in parallel. The first switch 121 is a low-impedance controllable electronic switch that can be controlled by the control unit 130 to turn on and off, and can be, for example, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) of LOWRds(ON). . After being powered on, the control unit 130 controls the first switch 121 to be turned on, so as to provide a heavy-duty charging circuit for the device to be charged. The second switch 122 is a controllable electronic switch that can be controlled by the control unit 130 to switch on and off. The impedance of the electronic switch is not required, and it can be, for example, a MOSFET. The second switch 122 is turned on, providing a light-load working path for the device to be charged. The second detection unit 112 is used for detecting the magnitude of the charging current output by the power supply to the device to be charged in the light load working state. In an implementation manner, the second detection unit 112 detects the magnitude of the charging current when the second switch 122 is turned on, and the second detection unit 112 may be composed of an ohm-level precision resistor, for example. Wherein, the control unit may be, for example, an MCU (MicroControl Unit, also known as a single chip microcomputer, SingleChipMicrocomputer).

Further referring to FIG. 5 , it shows a flow chart 500 of an embodiment of a method for judging that a device is fully charged according to the present application.

As shown in FIG. 5 , in step 501 , electric parameters of the device to be charged are detected when charging. Then, in step 502, switch between the light load charging circuit and the heavy load charging circuit according to the magnitude of the electrical parameter. Finally, in step 503, it is determined whether the charging is saturated according to the rate of change of the electrical parameter. Since the rate of change of electrical parameters such as current or voltage will be relatively small when the electronic device is about to be fully charged, it can be judged whether the charging is saturated based on this point. Further optionally, a rate of change threshold may be set, and when the rate of change of the electrical parameter is less than the threshold, it is determined that the charging is saturated.

In some optional embodiments, the above method further includes judging whether the device to be charged is in a light load working state according to a relationship between the electrical parameter and a preset light load threshold. In a further embodiment, the above method further includes: in response to judging that the device to be charged is not in a light-load working state, switching to the heavy-load charging circuit; in response to judging that the to-be-charged device is in a light-load working state, switch for the light load charging circuit.

In other optional embodiments, the above method further includes judging whether the charging is saturated according to the relationship between the electrical parameter and a preset saturation threshold. In a further embodiment, the above method further includes: in response to judging that the device to be charged is in a light-load working state, periodically switching to the light-load charging circuit, and judging whether the charging is saturated; in response to judging that the charging is not saturated , switching to the heavy load charging circuit; and in response to judging that the charging is saturated, sending an indication message of charging saturation to the user and/or sending a control signal to the device to be charged so that it stops outputting charging current. Wherein, when it is judged that the charging is not saturated, switch to the heavy-load charging circuit, and periodically switch back to the light-load charging circuit to detect the magnitude of the electrical parameters, and thus determine whether the charging is saturated.

The method for judging the charging saturation of the device of the present invention realizes judging the charging saturation in time and avoids the waste of electricity caused by overcharging. Furthermore, since the circuit works in the heavy-load charging circuit most of the time, the efficiency will not be affected by working in the light-load charging circuit for a long time, and the light-load working state and charge saturation can be accurately detected.

It should be understood that each step described in the method for judging that the device is fully charged corresponds to the unit or module in the device described with reference to FIG. 1 , FIG. 2 , FIG. 3 and FIG. 4 . Therefore, the operations and features described above for the device are also applicable to the method for judging that the device is fully charged and the steps included therein, and will not be repeated here.

The units involved in the embodiments described in the present application may be implemented by means of software or by means of hardware. The described units may also be set in a processor, for example, it may be described as: a processor includes a detection unit, a switching unit and a control unit. Wherein, the names of these units do not constitute a limitation to the unit itself under certain circumstances, for example, the detection unit may also be described as "a unit for detecting electrical parameters when the device to be charged is charged".

The above description is only a preferred embodiment of the present application and an illustration of the applied technical principle. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solution formed by the specific combination of the above-mentioned technical features, but should also cover the technical solution formed by the above-mentioned technical features without departing from the inventive concept. Other technical solutions formed by any combination of or equivalent features thereof. For example, a technical solution formed by replacing the above-mentioned features with technical features with similar functions disclosed in (but not limited to) this application.

Claims (13)

1. the device that a judgment device charging is saturated, it is characterised in that described device includes:

Detection unit, for detecting electrical quantity during charging equipment charging；

Switch unit, is used for providing light load charging circuit and heavy duty charging circuit controlled unit to control to switch between two circuit；

Control unit, the size of the electrical quantity for detecting according to described detection unit controls switch unit and the size according to the rate of change of described electrical quantity judges whether charging is saturated.

2. the device that judgment device charging as claimed in claim 1 is saturated, it is characterised in that described control unit also includes:

According to described electrical quantity and the relation presetting light load threshold, light load judgment unit, for judging whether described charging equipment is in light load operation state.

3. the device that judgment device charging as claimed in claim 2 is saturated, it is characterised in that described control unit also include configuring for:

It is not at light load operation state in response to charging equipment described in described light load judgment unit judges, sends the signal switching to described heavy duty charging circuit to described switch unit；

It is in light load operation state in response to charging equipment described in described light load judgment unit judges, sends the signal switching to described light load charging circuit to described switch unit.

4. the device that judgment device charging as described in as arbitrary in claims 1 to 3 is saturated, it is characterised in that described control unit also includes:

According to the relation of described electrical quantity Yu default saturation threshold, saturated judging unit, for judging whether charging is saturated.

5. the device that judgment device charging as claimed in claim 4 is saturated, it is characterised in that described control unit is further configured to:

It is in light load operation state in response to charging equipment described in described light load judgment unit judges, periodically sends out the signal switching to described light load charging circuit, and judge whether charging is saturated by described saturated judging unit；

In response to judging that charging is unsaturated, send the signal switching to described heavy duty charging circuit to described switch unit；And

In response to judging that charging is saturated, issue the user with the saturated instruction information of charging and/or send control signal to described charging equipment so that it stops output charging current.

6. the device that judgment device charging as described in as arbitrary in Claims 1 to 5 is saturated, it is characterised in that described electrical quantity includes electric current, wherein

If described electric current is less than default light load threshold, then judge that described charging equipment is in light load operation state, otherwise, then it is in heavy duty duty；

When described electric current is less than when presetting light load threshold, if described electric current is more than default saturation threshold, then judge that charging is unsaturated, otherwise, then judge that charging is saturated.

7. the device that judgment device charging as described in as arbitrary in claim 1～6 is saturated, it is characterised in that described heavy duty charging circuit is realized by the first switch；And

Described light load circuit is realized by second switch.

8. the device that judgment device charging as claimed in claim 7 is saturated, it is characterised in that described first switch includes low-impedance controllable electronic switch.

9. the method that a judgment device charging is saturated, it is characterised in that described method includes:

Electrical quantity during detection charging equipment charging；

Size according to described electrical quantity, between light load charging circuit and heavy duty charging circuit switching and

The size of the rate of change according to described electrical quantity judges whether charging is saturated.

10. the method that judgment device charging as claimed in claim 9 is saturated, it is characterised in that described method also includes:

Judge whether described charging equipment is in light load operation state according to described electrical quantity and the relation presetting light load threshold.

11. the method that judgment device charging as claimed in claim 10 is saturated, it is characterised in that described method also includes:

In response to judging that described charging equipment is not at light load operation state, switch to described heavy duty charging circuit；

In response to judging that described charging equipment is in light load operation state, switch to described light load charging circuit.

The saturated method 12. the judgment device as described in as arbitrary in claim 9～11 is charged, it is characterised in that described method also includes:

Relation according to described electrical quantity Yu default saturation threshold judges whether charging is saturated.

13. the method that judgment device charging as claimed in claim 12 is saturated, it is characterised in that described method also includes:

In response to judging that described charging equipment is in light load operation state, periodically switch to described light load charging circuit, and judge whether charging is saturated；

In response to judging that charging is unsaturated, switch to described heavy duty charging circuit；And

In response to judging that charging is saturated, issue the user with the saturated instruction information of charging and/or send control signal to described charging equipment so that it stops output charging current.