Emergency power supply circuit

Abstract

The utility model discloses a power supply circuit of an emergency power supply, and belongs to the field of emergency power supplies. According to the emergency power supply circuit of the utility model, the charging output is used to supply power to the internal control circuit in a non-emergency state, the power supply is switched to the battery power supply only when the emergency state is entered, and the emergency power supply circuit of the utility model has the advantages of simple circuit, economy, practicability, cost saving, stability, reliability and prolonged service life of the battery.

Description

Technical Field

[0001] This utility model relates to an emergency power supply circuit, belonging to the field of emergency power supplies. Background Technology

[0002] The current emergency power supply's internal power supply characteristics for the control circuit are as follows:

[0003] The control unit is powered by a battery. The disadvantage is that after the battery is fully charged, the charging and discharging frequency increases, and under certain circumstances, it will affect the duration of emergency status. Utility Model Content

[0004] To solve at least one of the above problems, this utility model provides an emergency power supply circuit that enables the internal control circuit to be powered by the charging output in non-emergency states, and only switches to battery power when entering an emergency state. The technical solution is as follows.

[0005] This utility model discloses an emergency power supply circuit, comprising a battery B1, a fuse F1, a PNP transistor Q1, a P-type MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a Zener diode DZ1. One end of the fuse F1 is connected to the anode of the battery B1, and the other end is connected to the cathode of the first diode D1, one end of the first resistor R1, the cathode of the third diode D3, the emitter of the PNP transistor Q1, the drain of the P-type MOSFET Q2, and one end of the third resistor R3. The terminals are connected as follows: the anode of the first diode D1 is connected to the anode of the second diode D2; the other end of the first resistor R1 is connected to the cathode of the Zener diode DZ1 and one end of the second resistor R2; the anode of the third diode D3 and the other end of the second resistor R2 are connected to the base of the PNP transistor Q1; the collector of the PNP transistor Q1 is connected to the anode of the Zener diode DZ1, the cathode of the second diode D2, and the cathode of the fourth diode D4; the gate of the P-type MOSFET Q2 is connected to the other end of the third resistor R3; the source of the P-type MOSFET Q2 is connected to the anode of the fourth diode D4; and the ground of the battery B1 is connected to the reference ground GND.

[0006] In one embodiment of this utility model, the utility model can be divided into four states: charging, fully charged, testing, and emergency.

[0007] During charging, the charging circuit outputs voltage V. CHARGER_OUTPUT+ Higher than the control circuit power supply voltage V VCC+ and battery voltage V BATTERY+ By matching D1 and D2, V can be made VCC+ ≥V BATTERY+ At this point, Q1 is always in the cutoff state, and VRECHARGER_CONTROL R3 pulls Q2 high, causing it to cut off. The control circuit power supply VCC+ is powered by CHARGER_OUTPUT+. VCC+ =V CHARGER_OUTPUT+ -V f of D2 ;

[0008] When fully charged, the output voltage of the charging circuit is controlled to a lower level V. CHARGER_OUTPUT+min By selecting a breakdown voltage of V DZ1的 Zener diode DZ1 can make V VCC+ +V DZ1 ≥V BATTERY+ Ensure that Q1 is always in the cutoff state under this condition, V RECHARGER_CONTROL R3 pulls Q2 high, causing it to cut off. The control circuit power supply VCC+ is powered by CHARGER_OUTPUT+. VCC+ =V CHARGER_OUTPUT+ -V f of D2 ;

[0009] Under test conditions, the charging circuit output voltage is controlled to a low level V. CHARGER_OUTPUT+min V BATTERY+ >V CHARGER_OUTPUT+min V RECHARGE_CONTROL To control Q2 to turn on when the level is low, V VCC+ +V DZ1 >V BATTERY+ Q1 deadline, V VCC+ =V BATTERY+ -V DS of Q2 -V f of D4 ;

[0010] In an emergency, V CHARGER_OUTPUT+ =0, V VCC+ The battery continues to supply power from battery B1 until Q1 is turned on, V VCC+ =V BATTERY+ -V ec of Q1 .

[0011] In non-emergency situations, the control circuit is powered by the charging circuit, which does not consume the energy stored in the battery, reduces the charging and discharging frequency of the battery, and ensures the battery's retention time in emergency situations.

[0012] Advantages of this utility model:

[0013] This invention ensures that the control circuit is always powered by the charging stage under normal conditions, and only uses battery power when entering an emergency state, thereby reducing the charging and discharging frequency of the battery and ensuring the battery's retention time in an emergency state.

[0014] This invention features a simple, economical, and cost-effective circuit that is stable, reliable, and extends battery life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an emergency power supply circuit according to the present invention; Detailed Implementation

[0016] The following is a detailed description of this utility model.

[0017] Example 1

[0018] like Figure 1 The diagram shown is a schematic diagram of an emergency power supply circuit according to this utility model.

[0019] An emergency power supply circuit includes a battery B1, a fuse F1, a PNP transistor Q1, a P-type MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a Zener diode DZ1. One end of the fuse F1 is connected to the anode of the battery B1, and the other end is connected to the cathode of the first diode D1, one end of the first resistor R1, the cathode of the third diode D3, the emitter of the PNP transistor Q1, the drain of the P-type MOSFET Q2, and one end of the third resistor R3. The anode of the first diode D1 is connected to the anode of the second diode D2. The other end of the first resistor R1 is connected to the cathode of the Zener diode DZ1 and one end of the second resistor R2. The anode of the third diode D3 and the other end of the second resistor R2 are connected to the base of the PNP transistor Q1. The collector of the PNP transistor Q1 is connected to the anode of the Zener diode DZ1, the cathode of the second diode D2, and the cathode of the fourth diode D4. The gate of the P-type MOSFET Q2 is connected to the other end of the third resistor R3. The source of the P-type MOSFET Q2 is connected to the anode of the fourth diode D4. The ground of the battery B1 is connected to the reference ground GND.

[0020] The working principle of this utility model:

[0021] This utility model can be divided into four states: charging, fully charged, testing, and emergency.

[0022] During charging, the charging circuit outputs voltage V. CHARGER_OUTPUT+ Higher than the control circuit power supply voltage V VCC+ and battery voltage V BATTERY+By matching D1 and D2, V can be made VCC+ ≥V BATTERY+ At this point, Q1 is always in the cutoff state, and V RECHARGE_CONTROL R3 pulls Q2 high, causing it to cut off. The control circuit power supply VCC+ is powered by CHARGER_OUTPUT+. VCC+ =V CHARGER_OUTPUT+ -V f of D2 ;

[0023] When fully charged, the output voltage of the charging circuit is controlled to a lower level V. CHARGER_OUTPUT+min By selecting a breakdown voltage of V DZ1的 Zener diode DZ1 can make V VCC+ +V DZ1 ≥V BATTERY+ Ensure that Q1 is always in the cutoff state under this condition, V RECHARGE_CONTROL R3 pulls Q2 high, causing it to cut off. The control circuit power supply VCC+ is powered by CHARGER_OUTPUT+. VCC+ =V CHARGER_OUTPUT+ -V f of D2 ;

[0024] Under test conditions, the charging circuit output voltage is controlled to a low level V. CHARGER_OUTPUT+min V BATTERY+ >V CHARGER_OUTPUT+min V RECHARGE_CONTROL To control Q2 to turn on when the level is low, V VCC+ +V DZ1 >V BATTERY+ Q1 deadline, V VCC+ =V BATTERY+ -V DS of Q2 -V f of D4 ;

[0025] In an emergency, V CHARGER_OUTPUT+ =0, V VCC+ The battery continues to supply power from battery B1 until Q1 is turned on, V VCC+ =V BATTERY+ -V ec of Q1 .

[0026] In non-emergency situations, the control circuit is powered by the charging circuit, which does not consume the energy stored in the battery, reduces the charging and discharging frequency of the battery, and ensures the battery's retention time in emergency situations.

[0027] This invention is not limited to the power supply switching of different branches using discrete components as shown in the figure, but can also be other methods with intelligent detection and control of power supply switching.

[0028] This invention is not limited to internal power supply applications in emergency power supplies, but is also applicable to other circuits with similar power supply requirements.

[0029] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. An emergency power supply circuit, characterized in that, The emergency power supply circuit includes a battery B1, a fuse F1, a PNP transistor Q1, a P-type MOSFET Q2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, and a Zener diode DZ1. One end of the fuse F1 is connected to the anode of the battery B1, and the other end is connected to the cathode of the first diode D1, one end of the first resistor R1, the cathode of the third diode D3, the emitter of the PNP transistor Q1, the drain of the P-type MOSFET Q2, and one end of the third resistor R3. The anode of the first diode D1 is connected to the anode of the second diode D2. The other end of the first resistor R1 is connected to the cathode of the Zener diode DZ1 and one end of the second resistor R2. The anode of the third diode D3 and the other end of the second resistor R2 are connected to the base of the PNP transistor Q1. The collector of the PNP transistor Q1 is connected to the anode of the Zener diode DZ1, the cathode of the second diode D2, and the cathode of the fourth diode D4. The gate of the P-type MOSFET Q2 is connected to the other end of the third resistor R3. The source of the P-type MOSFET Q2 is connected to the anode of the fourth diode D4. The ground of the battery B1 is connected to the reference ground GND.

2. The emergency power supply circuit according to claim 1, characterized in that, The emergency power supply circuit has four states: charging, fully charged, testing, and emergency.

3. The emergency power supply circuit according to claim 2, characterized in that, Specifically, the charging state is as follows: In the charging state, the output voltage VCHARGER_OUTPUT+ of the charging circuit is higher than the power supply voltage VVCC+ of the control circuit and the battery voltage VBATTERY+. By matching D1 and D2, VVCC+ ≥ VBATTERY+ can be made. At this time, Q1 is always in the off state, and VRECHARGER_CONTROL is pulled high by R3 to make Q2 off. The power supply VCC+ of the control circuit is powered by CHARGER_OUTPUT+, and VVCC+ = VCHARGER_OUTPUT+ - Vf of D2.

4. The emergency power supply circuit according to claim 2, characterized in that, Specifically, the fully charged state is as follows: In the fully charged state, the output voltage of the charging circuit is controlled to a low level VCHARGER_OUTPUT+min. By selecting the Zener diode DZ1 with a breakdown voltage of VDZ1, VVCC++VDZ1≥VBATTERY+ can be ensured that Q1 is always in the off state in this state. VRECHARGER_CONTROL is pulled high by R3 to make Q2 cut off. The control circuit power supply VCC+ is powered by CHARGER_OUTPUT+, and VVCC+=VCHARGER_OUTPUT+-Vf of D2.

5. An emergency power supply circuit according to claim 2, characterized in that, The specific test state is as follows: Under the test state, the output voltage of the charging circuit is controlled to a lower level VCHARGER_OUTPUT+min, VBATTERY+>VCHARGER_OUTPUT+min, VRECHARGE_CONTROL is at a low level to control Q2 to turn on, VVCC++VDZ1>VBATTERY+, Q1 is turned off, and VVCC+=VBATTERY+-VDS of Q2-Vf of D4.

6. An emergency power supply circuit according to claim 2, characterized in that, The emergency state is specifically as follows: In the emergency state, VCHARGER_OUTPUT+=0, VVCC+ drops until Q1 is turned on and powered by battery B1, VVCC+=VBATTERY+-Vec of Q1.

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