CN105391434A - Intelligent switch circuit capable of disconnecting fully-charged charging load - Google Patents

Abstract

The invention relates to the technical field of intelligent control, in particular to an intelligent switch circuit with the function of intelligent disconnection after the charging load is fully charged, including a power supply module, a current acquisition module, a switch control module and a delay judgment module. The current acquisition module can obtain the real-time current flowing through the charging load; the delay judgment module can generate a delay after the charging load is in the standby state to prevent the switch from malfunctioning; the switch control module can control the switch to disconnect the charging load in the fully charged state. The invention judges the working state of the charging load by detecting the current flowing through the charging load, so as to realize the intelligent control of the switch, thereby effectively saving electric energy and being beneficial to environmental protection.

Description

Intelligent switch circuit with intelligent disconnection function after the charging load is fully charged

technical field

The invention relates to the technical field of intelligent control, in particular to an intelligent switch circuit with the function of intelligent disconnection after the charging load is fully charged.

Background technique

With the rapid development of the electronic information industry, more and more new electronic products, especially portable electronic products such as mobile phones, tablet computers, and digital cameras, are appearing on the market. These electronic products need to be recharged when there is a low power condition. The charging control strategy of conventional chargers is relatively simple. After the battery is fully charged, because the rectifier device and electronic components in the circuit are still in working state, there is power loss, which is not conducive to energy saving. In addition, charging for a long time will easily cause overcharging, shorten the service life of the battery, cause damage to the charging equipment, and pose a safety hazard.

Contents of the invention

The technical problem to be solved by the present invention is to provide an intelligent switch circuit with the function of intelligent disconnection after the charging load is fully charged, so as to achieve the goals of energy saving, safe use of electricity, and prevention of overcharging.

The present invention adopts the following technical means to realize the object of the invention.

An intelligent switch circuit with intelligent disconnection after charging load is fully charged, including a current acquisition module, a switch control module and a delay judgment module.

As a further limitation of the technical solution, the current acquisition module includes a diode D1 and a resistor R1, the anode of the diode D1 is connected to the power supply, the cathode of the diode D1 is connected to the resistor R1, and the resistor R1 is connected to the charging load.

As a further limitation of this technical solution, the switch control module includes a resistor R2, a resistor R3, a comparator A, a diode D2, a comparator B, a resistor R4, a field effect transistor Q1, and a resistor R9, and the non-inverting input of the comparator A The terminal and resistor R3 are connected in series between the resistor R1 and the charging load, the inverting input terminal of the comparator A and the resistor R2 are connected in series between the resistor R1 and the cathode of the diode D1, and the output terminal of the comparator A is connected to the diode D2 The cathode, the non-inverting input terminal of the comparator B and the resistor R4 are connected in series between the resistor R1 and the cathode of the diode D1, the inverting input terminal of the comparator B is connected to the anode of the diode D2, and the source of the field effect transistor Q1 Grounded, the gate of the field effect transistor Q1 and the resistor R9 are connected in series with the output terminal of the comparator B.

As a further limitation of the technical solution, the delay judgment module includes a resistor R7 and a capacitor C4, one end of the resistor R7 is connected between the resistor R1 and the cathode of the diode D1, and the other end of the resistor R7 is connected to the capacitor C4 and the inverting input terminal of the comparator B and the anode of diode D2, and the other end of capacitor C4 is grounded.

The beneficial effects of the present invention are: the present invention provides a solution to the common problem of charging load energy consumption, thereby saving a lot of resources and making great contributions to environmental protection.

Description of drawings

Fig. 1 is a schematic flow chart of the present invention.

Fig. 2 is a mobile phone charging power diagram of the present invention.

Fig. 3 is a charging power diagram of the tablet computer of the present invention.

Fig. 4 is a diagram of the electric vehicle charging power of the present invention.

Fig. 5 is a charging characteristic diagram of the present invention.

Fig. 6 is a circuit diagram of the control section of the present invention.

detailed description

The present invention provides an intelligent switch circuit that solves energy consumption after the charging load is fully charged. The composition, structure and implementation steps of the present invention will be described below in conjunction with accompanying drawings 1-6.

The circuit structure is as follows:

As shown in Figure 6, an intelligent switch circuit with intelligent disconnection after the charging load is fully charged includes a current acquisition module, a switch control module and a delay judgment module. The current acquisition module includes a diode D1 and a resistor R1, the anode of the diode D1 is connected to the power supply, the cathode of the diode D1 is connected to the resistor R1, the resistor R1 is connected to the charging load V1 (5.3V), and the resistor R1 is also connected to the capacitor C2 (0.1 μF) and the capacitor C1 (1000μF). The switch control module includes resistor R2 (47.5KΩ), resistor R3 (47KΩ), comparator A (U1A in Figure 6), diode D2, comparator B (U3B in Figure 6), resistor R4 (100KΩ), field effect Transistor Q1, resistor R9 (2.2Ω), the non-inverting input terminal of the comparator A and the resistor R3 are connected in series between the resistor R1 and the charging load, and the inverting input terminal of the comparator A and the resistor R2 are connected in series to the resistor R1 Between the cathode of the diode D1, the output terminal of the comparator A is connected to the cathode of the diode D2, the non-inverting input terminal of the comparator B and the resistor R4 are connected in series between the resistor R1 and the cathode of the diode D1, the comparator B The inverting input terminal is connected to the anode of the diode D2, the source of the field effect transistor Q1 is grounded, and the gate of the field effect transistor Q1 is connected in series with the output terminal of the comparator B with the resistor R9. The delay judgment module includes a resistor R7 (1MΩ) and a capacitor C4 (10μF). One end of the resistor R7 is connected between the resistor R1 and the cathode of the diode D1, and the other end of the resistor R7 is connected to the capacitor C4, the inverting input terminal of the comparator B and the diode The anode of D2 and the other end of capacitor C4 are grounded. In Figure 6, the circuit also includes R8 (300KΩ), R5 (47KΩ), R6 (47KΩ), R15 (10KΩ), R14 (10KΩ), R11 (1KΩ), R10 (1KΩ), C3 (0.1μF), LED1, R8 is connected to R4 and grounded, one end of R5 is connected to the inverting input of comparator A, the other end of R5 is grounded, one end of R6 is connected to the non-inverting input of comparator A, the other end of R6 is grounded, and one end of R14 is connected to comparator A Output terminal, the other end of R14 is connected between resistor R1 and the cathode of diode D1 and one end of R15, the other end of R15 is connected to the output end of comparator B, the connection relationship of R11, R10, C3 and LED1 in the circuit is also shown in the figure 6.

The implementation steps of this circuit are as follows: monitor the real-time current flowing through the charging load, the present invention uses the resistor R1 to detect the current flowing through the charging load, and when there is current flowing, the resistor R1 produces a voltage drop;

Determine whether the charging load is in the charging state or in the standby state according to the current size (set a current reference value I, when the detected current of the charging load is greater than I, the charging load is in the charging state; when the detected current of the charging load is less than I, then the charging load is in the standby state): set the current reference value I by setting the resistance value of the resistor R2; during normal charging, the resistor R1 produces a large voltage drop, which is sent to the inverting terminal of the voltage comparator A than The voltage of the non-inverting terminal is high, so the comparator A outputs a low level, and the voltage of the inverting terminal of the comparator B is pulled down through the diode D2, and the output of the comparator B is high to control the continuous conduction of the field effect transistor Q1; when the current drops to the reference When the current I is below, the voltage at the inverting terminal of comparator A will drop below the non-inverting terminal, diode D2 will be cut off, and resistor R7 will charge capacitor C4. When the voltage at the inverting terminal of comparator B is higher than the non-inverting terminal, the field effect transistor Q1 At this time, the charging load is in the standby state;

Record the duration of the charging load in the standby state;

Set a time parameter T, when the standby time of the charging load is greater than T, it is determined that the charging load is fully charged, and the switch automatically cuts off the power supply of the electrical appliance. Resistor R7 and capacitor C4 in the figure determine the delay time. If you plug in the charger directly without connecting the charging load, the power will be cut off after time T.

Figure 2 is a charging power diagram drawn after monitoring the real-time power and power when charging the mobile phone. It can be clearly seen from Figure 2 that the power is relatively stable before the mobile phone is charged to about 90%, with small fluctuations between 6.4W and 5.8W. When the power of the mobile phone is charged from 90% to 98%, that is, when the mobile phone is almost fully charged, the power drops significantly, that is, from 5.8W to 3.4W. After that, the mobile phone is fully charged, but there is still 2.2W-1.0W about power.

Figure 3 is a charging power diagram drawn after monitoring the real-time power and electric quantity when charging the tablet computer. It can be clearly seen from Figure 3 that the power is relatively stable before the tablet is charged to about 90%, with small fluctuations between 13.8W and 10.3W. When the tablet is charged from 90% to 97%, that is, when the tablet is almost full, the power drops significantly, that is, from 10.3W to 6.4W. After that, the tablet is fully charged, but still has 4.7W about power.

Among them, Figure 4 is the charging power diagram drawn after monitoring the real-time power and power when charging the electric vehicle. Compared with other small charging equipment, the charging power of the electric vehicle is relatively large, and the charging power cannot be displayed, only Is it full. It can be seen from Figure 4 that during the charging process of the electric vehicle, the power when the battery is fully charged is 17.4W. Since then, the electric vehicle has maintained a fully charged state, but still has a power of about 4.5W-3.9W.

Among them, Figure 5 is a charging characteristic diagram drawn with mobile phones and tablet computers as the research objects. It can be seen from Figure 5 that although different loads have different capacities and different charging times, they all drop to about 20mA after the battery is fully charged, and the final charging current tends to be several milliamperes.

The following is the actual workflow of the present invention:

1. Continuous charging process:

The current in the smart switch circuit is greater than I → the voltage at the inverting terminal of voltage comparator A is higher than the voltage at the non-inverting terminal → voltage comparator A outputs low level → secondary rectifier tube D2 conducts → comparator B outputs high level → field effect tube continues On → the smart switch is on.

2. The process of fully charging:

The current in the smart switch circuit is less than I → the voltage at the inverting terminal of voltage comparator A is lower than that of the non-inverting terminal → voltage comparator A outputs high level → secondary rectifier tube D2 cuts off → comparator B outputs low level → FET cuts off → The smart switch is off.

The above is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims (4)

1. An intelligent switch circuit with the function of intelligent disconnection after the charging load is fully charged, which is characterized in that it includes a current acquisition module, a switch control module and a delay judgment module. 2. The intelligent switch circuit according to claim 1, which has the function of intelligent disconnection after the charging load is fully charged, wherein the current acquisition module includes a diode D1 and a resistor R1, the anode of the diode D1 is connected to the power supply, and the cathode of the diode D1 is connected The resistor R1 is connected to the charging load. 3. The intelligent switch circuit according to claim 2, which has the function of intelligent disconnection after the charging load is fully charged, wherein the switch control module includes a resistor R2, a resistor R3, a comparator A, a diode D2, and a comparator B , resistor R4, field effect transistor Q1, resistor R9, the non-inverting input terminal of the comparator A and the resistor R3 are connected in series between the resistor R1 and the charging load, the inverting input terminal of the comparator A and the resistor R2 are connected in series Between the resistor R1 and the cathode of the diode D1, the output terminal of the comparator A is connected to the cathode of the diode D2, the non-inverting input terminal of the comparator B and the resistor R4 are connected in series between the resistor R1 and the cathode of the diode D1, the comparator The inverting input terminal of B is connected to the anode of the diode D2, the source of the field effect transistor Q1 is grounded, and the gate of the field effect transistor Q1 is connected in series with the output terminal of the comparator B with the resistor R9. 4. The intelligent switch circuit according to claim 3 with the function of intelligent disconnection after the charging load is fully charged, characterized in that: the delay judgment module includes a resistor R7 and a capacitor C4, and one end of the resistor R7 is connected to the resistor R1 and the diode D1 Between the cathodes, the other end of the resistor R7 is connected to the capacitor C4, the inverting input terminal of the comparator B and the anode of the diode D2, and the other end of the capacitor C4 is grounded.