CN102593908A - Backup power supply system - Google Patents

Abstract

The embodiment of the invention discloses a backup power supply system, which includes a backup battery, an input interface, an output interface and a key switch. It also includes: charging circuit, respectively connected to the input interface and the backup battery for charging the backup battery; power detection circuit, connected to the backup battery to detect the power of the backup battery; boost control circuit, respectively connected to the backup battery and the output interface It is used to charge the external load; the button detection circuit is connected with the charging circuit, the power detection circuit and the boost control circuit respectively, and is used to control the power detection circuit and the boost control circuit according to the key signal of the key switch; the charging circuit, the power The detection circuit, boost control circuit and key detection circuit are integrated in the main control chip. The backup power supply system of the embodiment of the present invention has high integration, extremely low standby power consumption, and its external circuit structure is simple, easy to realize and low in cost.

Description

backup power system

technical field

The invention relates to the technical field of switching power supply and linear power supply, in particular to a backup power supply system.

Background technique

With the advent of the digital age, various portable electronic devices such as mobile phones, digital cameras, MP3, etc. have been popularized. More and more functions are integrated into electronic devices such as mobile phones, so the power consumption of these portable electronic devices has also increased sharply, and there is a higher requirement for battery capacity. However, for the sake of aesthetics and portability, the volume of electronic devices is getting smaller and smaller, and the capacity of batteries is limited. In order to meet people's demand for battery capacity, especially the demand for power when traveling, backup power for portable electronic devices has emerged as the times require.

The battery of the backup power supply has more than 3 to 5 times the power of ordinary mobile phone batteries, and can charge electronic devices such as mobile phones independently for many times, which can meet people's power demand for a long period of time. However, the backup power system currently on the market is mainly realized through the control of discrete devices and single-chip microcomputers. Its charging system, discharging system and button control system are all set separately, so the volume is very large and it is not convenient to carry.

Contents of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a backup power supply device, which has high integration, simple external circuit structure and small volume.

In order to solve the above technical problems, an embodiment of the present invention proposes a backup power supply system, including a backup battery, an input interface, an output interface, and a key switch. The system also includes:

The charging circuit is respectively connected to the input interface and the backup battery for charging the backup battery;

A power detection circuit connected to the backup battery for detecting the power of the backup battery;

A boost control circuit is connected to the backup battery and the output interface respectively for charging an external load;

The key detection circuit is respectively connected with the charging circuit, the power detection circuit and the boost control circuit for controlling the power detection circuit and the boost control circuit according to the key signal of the key switch;

The charging circuit, power detection circuit, boost control circuit and key detection circuit are integrated in the main control chip.

The beneficial effect of the embodiment of the present invention is that: the backup power supply system of the embodiment of the present invention integrates the charging circuit, the power detection circuit, the boost control circuit and the key detection circuit into the main control chip. It has high integration, extremely low standby power consumption, and its external circuit structure is simple, easy to implement and low in cost.

Description of drawings

FIG. 1 is a circuit diagram of a backup power supply system according to an embodiment of the present invention.

Fig. 2 is an internal block diagram of the main control chip of the backup power supply system according to the embodiment of the present invention.

Detailed ways

As shown in Figure 1, it is a circuit diagram of the backup power supply system of the present invention. The backup power system of the present invention includes: a backup battery 101 , an input interface 102 , an output interface 103 and a key switch 104 . The system also includes: a charging circuit 201 , a power detection circuit 202 , a boost control circuit 203 and a key detection circuit 204 . Wherein, the charging circuit 201 is respectively connected with the input interface 102 and the backup battery 101 for charging the backup battery 101 through an external DC source. The power detection circuit 202 is connected to the backup battery 101 for detecting the power of the backup battery 101 . The boost control circuit 203 is respectively connected to the backup battery 101 and the output interface 103 so as to charge the external load through the backup battery 101 . The key detection circuit 204 is connected with the charging circuit 201, the electric quantity detection circuit 202, the boost control circuit 203 and the key switch 104 respectively, and the key detection circuit 204 is used for controlling the electric quantity detection circuit 202 and the boost control circuit according to the key signal of the key switch 104 203 for control. Wherein, the charging circuit 201 , the power detection circuit 202 , the boost control circuit 203 and the button detection circuit 204 are integrated in the main control chip 200 as shown in FIG. 2 . The backup power supply system of the invention has high integration and small volume.

1 and 2, the main control chip 200 of the backup power system has 15 pins. The VCC pin is the power supply pin of the main control chip 200 , the char pin is the charging pin for charging the backup battery 101 , and the EN pin is the charging enable terminal of the main control chip 200 . The EN pin is connected to the positive pole of the input interface 102. When the input interface 102 is electrically connected to the external DC source, the EN pin is at a high level, the main control chip 200 works normally, and the charging circuit 201 supplies power to the backup battery 101 through the external DC source. Charging; when the input interface 102 is disconnected from the external DC source, the EN pin is at low level, and the main control chip 200 enters standby mode to reduce power consumption. The VCC pin is connected to the anode of the input interface 102 through the first diode 111 , and the char pin is connected to the anode of the backup battery 101 . As shown in FIG. 2 , the charging circuit 201 includes: a charging control module 2011 and a first charging switch tube 2012 . The charging control module 2011 is connected with the button detection circuit 204, the charging control module 2011 and the button detection circuit 204 are both connected with the EN pin, the grid of the first charging switch tube 2012 is connected with the charging control module 2011, and the source is connected with VCC The pins are connected, and the drain is connected to the char pin. When the input interface 102 is electrically connected to an external DC source, the EN pin is at a high level, and the charging control module 2011 drives the first charging switch tube 2012 to obtain a constant current to charge the backup battery 101 .

The backup power system also includes a charging extension module connected to the input interface 102 , the charging circuit 201 and the backup battery 101 respectively. The charging expansion module adopts the second charging switch tube 107 as shown in FIG. 1 . The EXT1 pin is the charging and driving extension pin of the backup battery 101. The EXT1 pin is connected to the charging control module 2011 through the first drive buffer 211, and the EXT1 pin is connected to the gate of the second charging switch tube 107 outside the main control chip 200. The source of the second charge switching tube 107 is connected to the anode of the input interface 102 through the first diode 111 , and the drain is connected to the anode of the backup battery 101 . The charging control module 2011 drives the second charging switch tube 107 through the first driving buffer 211 , so as to increase the charging current of the backup battery 101 as required.

As shown in FIG. 2 , the boost control circuit 203 is connected to the backup battery 101 , the output interface 103 and the key detection circuit 204 respectively. The boost control circuit 203 starts to work according to the boost control signal output by the key detection circuit 204 . The electric energy output by the backup battery 101 is boosted to charge an external load through the output interface 103 . As shown in the figure, the SW pin is the output pin of the boost control circuit 203, the VFB pin is the feedback pin of the boost control circuit 203, the STB pin is the standby pin of the boost control circuit 203, and the EXT pin is the boost control circuit 203 pin. The drive expansion pin of the voltage control circuit 203. The boost control circuit 203 includes an error comparison amplifier, the output terminal of the error comparison amplifier is connected to the gate of the first boost drive switch tube 214, and the drain of the first boost drive switch tube 214 is connected to the SW pin. The pin is connected to the anode of the output interface 103 through the second diode 112 , and then the electric energy output by the backup battery 101 is boosted to charge an external load through the output interface 103 . The source of the first boost driving switch tube 214 is grounded through the current detection resistor 215 . The current detection resistor 215 is used to detect the peak current of the first boost drive switch tube 214 so as to perform cycle-by-cycle over-current protection and sampling of the current loop to ensure system stability. The negative input terminal of the error comparison amplifier is connected to the VFB pin, and the VFB pin is connected to the positive pole of the output interface 103 for feeding back the output voltage of the boost control circuit 203 to the error comparison amplifier. After the control logic processing, the duty cycle of the output driving signal is controlled, that is, the duty cycle of the first boost drive switch 214 is controlled, so as to adjust the output voltage to stabilize the output voltage at a set value. the

The backup power system also includes a boost expansion module connected to the backup battery 101 , the boost control circuit 203 and the positive pole of the output interface 103 respectively. The boost expansion module uses the second boost drive switch tube 108 as shown in FIG. 1 . The EXT pin is a boost drive extension pin, and the EXT pin is connected to the output terminal of the error comparison amplifier of the boost control circuit 203 through the third drive buffer 213, and the EXT pin is connected to the second booster outside the main control chip 200. The gate of the voltage-driven switch tube 108 is connected, the source of the second boost-driven switch tube 108 is grounded, and the drain is connected to the anode of the output interface 103 through the second diode. The boost control circuit 203 drives the second boost drive switch tube 108 through the third drive buffer 213 , thereby increasing the current output capability to charge the external load faster.

The backup power system also includes a boost circuit standby module connected to the boost control circuit 203 and the output interface 103 respectively. The standby module of the boost circuit adopts the standby control switch tube 109 as shown in FIG. 1 . The STB pin is the standby pin of the boost control circuit 203, the STB pin is connected with the boost control circuit 203 through the second drive buffer 212, and the STB pin is connected to the gate of the standby control switch tube 109 outside the main control chip 200 The source of the standby control switching tube 109 is grounded, and the drain of the standby control switching tube 109 is connected to the negative pole of the output interface 103 . After the external load is charged, the boost control circuit 203 makes the STB pin output a low-level signal through the second drive buffer 212, turns off the standby control switch tube 109, cuts off the connection between the external load and the backup power system, and enters the standby state To obtain extremely low standby power consumption while protecting the backup power system; when an overload or even a short circuit occurs, the STB pin will automatically output a low-level signal to turn off the standby control switch tube 109, and turn it on once every 5s, and the turn-on time lasts about 1ms is used to detect whether the overload or short circuit status is eliminated. If it is eliminated, it will resume normal operation. If it is not eliminated, it will automatically enter the next cycle to protect the entire backup power system.

The backup power supply system of the present invention also includes a lighting module and a power display module 105 . Wherein, the lighting module includes a lighting driving circuit 205 and a high brightness LED lamp 106 . The lighting driving circuit 205 is connected with the key detection circuit 204 , the high brightness LED lamp 106 is connected with the lighting driving circuit 205 , and the lighting driving circuit 205 is integrated in the main control chip 200 . The lighting drive circuit 205 includes: a lighting control module 2051 connected to the key detection circuit 204 , a lighting switch tube 2053 and a voltage-controlled resistor 2052 . The lighting control module 2051 is connected to the grid of the lighting switching tube 2053, the source of the lighting switching tube 2053 is connected to the voltage-controlled resistor 2052, the drain of the lighting switching tube 2053 is connected to the LED pin of the main control chip 200, and the LED tube The pin is connected with the high brightness LED lamp 106 outside the main control chip 200 . When the lighting control module 2051 receives the lighting start signal from the key detection circuit 204, the lighting control module 2051 controls the lighting switch tube 2053 to drive the high-brightness LED lamp 106 to emit light, and adjusts the resistance value of the voltage-controlled resistor 2052 to make the high-brightness LED lamp The current of 106 is fixed at 50mA. When the lighting control module 2051 receives the lighting off signal from the key detection circuit 204, the lighting control module 2051 turns off the lighting switch tube 2053.

The power display module 105 is connected to the power detection circuit 202. The power display module 105 includes a plurality of indicator lights. In this embodiment, the first indicator light 1051, the second indicator light 1052, the third indicator light 1053 and the fourth indicator light 1054 . The power display module 105 controls the light of the corresponding indicator lights by controlling the states of the first switch tube 2021 , the second switch tube 2022 , the third switch tube 2023 and the fourth switch tube 2024 according to the detected battery capacity of the backup battery 101 state, and then display the power level of the backup battery 101 through the light-emitting states of the four indicator lights. The L1-L4 pins are backup battery power display pins, which are respectively connected to the corresponding first switch tube 2021 , second switch tube 2022 , third switch tube 2023 and fourth switch tube 2024 . The specific settings are as follows: when the electric quantity of the reserve battery 101<25% full electric quantity, all 4 indicator lights are flashing; Two indicator lamps are flickering, when 50% full electric quantity<backup battery 101 electric quantity<75% full electric quantity, the first indicator light 1051 and the second indicator light 1052 are always on, the third indicator light 1053 and the fourth indicator light 1054 are flickering, When 75% of the full power<the power of the backup battery 101<100% of the full power, an indicator light 1051, a second indicator light 1052 and a third indicator light 1053 are always on, and the fourth indicator light 1054 flashes; when the backup battery 101 is fully charged , 4 indicator lights are always on.

The KEY pin is a key control pin, which is connected to the key detection circuit 204 and is externally connected to the key switch 104 . The key detection circuit 204 includes: a detection module, a first sub-control module and a second sub-control module. Wherein, the detection module is connected to the EN pin of the charging enable terminal of the main control chip 200 , and the detection module is connected to the key switch 104 through the KEY pin, and the EN pin is connected to the positive pole of the input interface 102 . The first sub-control module is connected to the detection module. When the detection module detects the charging enable signal, that is, when the input interface 102 is connected to the external DC source and the EN pin is at a high level, the first sub-control module is used to control The power detection circuit 202 continues to work. When the charging enable signal is not detected, the first sub-control module controls the power detection circuit 202 according to the key signal of the key switch 104 . The second sub-control module is connected with the detection module. When the detection module detects the charging enable signal, that is, when the input interface 102 is connected to the external DC source and the EN pin is at a high level, the second sub-control module is used to control The boost control circuit 203 prohibits its operation. When the charging enable signal is not detected, the second sub-control module controls the boost control circuit 203 to work according to the key signal of the key switch 104 .

That is, when the input interface 102 is connected to the external DC source, the EN pin is at a high level, the power detection circuit 202 continues to work, and the boost control circuit 203 is disabled, both of which are not controlled by the key switch 104, and the key switch 104 Only control the lighting drive circuit 205. At this time, press the key switch 104 twice, the key detection circuit 204 outputs a lighting start signal, the lighting control module 2051 controls the lighting switch tube 2053 to drive the high-brightness LED lamp 106 to emit light, and then press the key switch twice 104 , the lighting off signal sent by the key detection circuit 204 , and the lighting control module 2051 turns off the lighting switch tube 2053 .

In the non-charging stage, that is, when the EN pin is at a low level, the power detection circuit 202 , the boost control circuit 203 and the lighting driving circuit 205 are all controlled by the key switch 204 . Press the key switch 104 once, the power display module 105 displays the power for 5 seconds, and the boost control circuit 203 starts to work at the same time; Then turn off the high-brightness LED lamp 106; press and hold the key switch 104 for 3 seconds, then turn off the boost control circuit 203.

When the input interface 102 of the backup power system is connected to an external DC source, the system starts to charge the backup battery 101 through the built-in first charging switch tube 2012 of the main control chip 200 and the external second charging switch tube 107. If the interface 103 is connected to an external load, then the system can simultaneously charge the external load through the third diode 113 . At this time, in order to ensure that the backup battery 101 does not charge the external load during the direct charging process of the external DC source, the backup power system of the present invention disables the boost control circuit 203 by setting the EN pin of the charging enable terminal.

The backup power supply system of the present invention can charge external loads such as mobile phones independently through the backup battery 101, and can also charge its own backup battery 101 and external loads at the same time through a DC source. The backup power system also has a power display function of the backup battery 101, which can display the power of the backup battery 101 through four indicator lights; the backup power system also has a lighting function. The backup power supply system has a constant current charging function, and by adding a charging expansion module, the charging current is divided into two levels: large and small. When the voltage of the backup battery 101 is too low, it is charged with a small current to prolong the life of the backup battery 101. When the voltage of the backup battery 101 rises to a certain value, it starts charging with a large current to shorten the charging time.

The above are specific implementations of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also considered Be the protection scope of the present invention.

Claims (9)

1. a backup power system comprises backup battery, input interface, output interface and key switch, it is characterized in that, said system also comprises:

Charging circuit, being connected with backup battery with input interface respectively is used for to said backup battery charging;

The electric weight testing circuit, being connected with said backup battery is used to detect the electric weight of backup battery;

Boost control circuit, being connected with said output interface with said backup battery respectively is used for charging to external loading;

Key press detecting circuit, being connected with said charging circuit, electric weight testing circuit and boost control circuit respectively is used for controlling said electric weight testing circuit and boost control circuit according to the push button signalling of key switch;

Said charging circuit, electric weight testing circuit, boost control circuit and key press detecting circuit are integrated in the main control chip.

2. backup power system as claimed in claim 1 is characterized in that, said key press detecting circuit comprises:

Detection module, the charging Enable Pin with key switch and main control chip is connected respectively, and said charging Enable Pin is connected with the positive pole of said input interface;

The first sub-control module; Be connected with said detection module; When said detection module detects the charging enable signal, control said boost control circuit and turn-off, when detecting the charging enable signal, do not control said boost control circuit according to the push button signalling of key switch;

The second sub-control module; Be connected with said detection module; When said detection module detects the charging enable signal, control said electric weight testing circuit and start, when detecting the charging enable signal, do not control said electric weight testing circuit according to the push button signalling of key switch.

3. backup power system as claimed in claim 1 is characterized in that, said system also comprises the electricity quantity display module that is connected with said electric weight testing circuit.

4. backup power system as claimed in claim 3 is characterized in that said electricity quantity display module comprises a plurality of indicator lights.

5. backup power system as claimed in claim 1; It is characterized in that; Said system also comprises lighting module; Said lighting module comprise be connected with said key press detecting circuit, open or illumination driving circuit of closing and the high-brightness LED lamp that is connected with said illumination driving circuit according to push button signalling, said illumination driving circuit is integrated in the said main control chip.

6. backup power system as claimed in claim 1 is characterized in that, said system also comprises the charging expansion module that is connected with said input interface, charging circuit and backup battery respectively.

7. backup power system as claimed in claim 1 is characterized in that, said system also comprises the expansion module that boosts that is connected with the positive pole of said backup battery, boost control circuit and output interface respectively.

8. backup power system as claimed in claim 1 is characterized in that, said system also comprises the booster circuit standby module that is connected with the negative pole of said boost control circuit and output interface respectively.

9. backup power system as claimed in claim 1 is characterized in that, said input interface and output interface are electrically connected with outside DC source and external loading respectively with realization and charge to external loading.

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