A fire protection circuit with self-locking function when power is cut off and power is back up

Abstract

The present invention discloses a fire protection circuit with power-off backup and self-locking, including a power interface electrically connected to a main power supply and a battery interface electrically connected to an auxiliary power supply; the power interface and the battery interface of the main power supply are both electrically connected to a step-down circuit, and the step-down circuit is electrically connected to a comparator self-locking circuit; the main power supply is electrically connected to a main control system, and the main control system is electrically connected to a fire signal interface, and the fire signal interface is electrically connected to a switch tube self-locking circuit and a fire equipment interface; the switch tube self-locking circuit is electrically connected to a switch circuit, and the switch circuit is electrically connected to a comparator self-locking circuit, a fire equipment interface and a battery interface. The present invention solves the problem that the fire alarm disappears due to the time difference when the backup power supply is switched when the fire protection is started. At the same time, when the fire protection is started, the external inexhaustible electric energy is used first, and in an emergency, the backup power supply inside the cabinet is used to maximize the power supply of the fire protection device.

Description

Technical Field

[0001] The present invention belongs to the field of fire protection of power exchange cabinets, and in particular relates to a fire protection circuit with self-locking function of power failure and backup power. Background Art

[0002] At present, the charging and swapping cabinets on the market basically directly output a start signal for the fire protection device after the fire warning is triggered, and the control of the fire protection device after the start signal is all controlled by the main control device in the original system. However, when the power is cut off due to a fire, the main control device is powered off and cannot output the start signal, resulting in the inability to achieve fire protection. Therefore, some people will set up a backup power supply, that is, after the main power supply fails, switch to the backup power supply to power the main control device.

[0003] When switching to the backup power supply, there is a time difference, which will cause the main control device to lose power and lose the original fire alarm. If the fire alarm signal is placed in a storage space that will not be lost during power failure, a switch or device is required to eliminate the fire signal, which increases the complexity of the system and increases the probability of false triggering of the switch or device in the fire state. Summary of the invention

[0004] In order to solve the above problems, the present invention discloses a fire protection circuit with power failure and backup power self-locking. The present invention solves the problem that the fire alarm disappears due to the time difference when the backup power supply is switched when the fire protection is started. At the same time, when the fire protection is started, the external inexhaustible electric energy is used first, and in an emergency, the backup power supply inside the cabinet is used to maximize the power supply of the fire protection device.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A fire protection circuit with power-off backup self-locking, comprising a power interface electrically connected to a main power supply and a battery interface electrically connected to an auxiliary power supply; the power interface and the battery interface of the main power supply are both electrically connected to a step-down circuit, and the step-down circuit is electrically connected to a comparator self-locking circuit; the main power supply is electrically connected to a main control system, the main control system is electrically connected to a fire signal interface, and the fire signal interface is electrically connected to a switch tube self-locking circuit and a fire equipment interface; the switch tube self-locking circuit is electrically connected to a switch circuit, and the switch circuit is electrically connected to a comparator self-locking circuit, a fire equipment interface and a battery interface; the main control system is connected to a plurality of fire sensors;

[0007] Among them, the switch tube self-locking circuit is used to receive the fire start signal transmitted by the fire signal interface. After receiving the fire start signal, the switch tube self-locking circuit makes and maintains the switch circuit in a driving connection state, and maintains the power supply of the main power supply and / or the auxiliary power supply to the fire equipment;

[0008] The comparator self-locking circuit is used to detect temperature. When the current temperature is detected to exceed the preset threshold, the comparator of the comparator self-locking circuit is reversed and the output signal is locked, so that the switching circuit is maintained in a driven connection state, maintaining the main power supply and / or auxiliary power supply to the fire-fighting equipment; the fire-fighting equipment interface is used to electrically connect the fire-fighting equipment.

[0009] As a further improvement, the main power source is low-voltage direct current converted from commercial power, and the auxiliary power source is a battery; the main power source is electrically connected to the auxiliary power source through a charging circuit.

[0010] Further improvement, the comparator self-locking circuit includes a comparator chip U3, a first pin of the comparator chip U3 is electrically connected to a twenty-ninth resistor R29, the twenty-ninth resistor R29 is electrically connected to a thirty-ninth resistor R39, a second diode D2, a twenty-eighth resistor R28, a fortieth resistor R40 and a twenty-eighth capacitor C28 respectively, the twenty-eighth resistor R28 is electrically connected to a thirty-first capacitor C31 and a first pin of the first switch tube Q1; the other end of the twenty-eighth capacitor C28 is electrically connected to the thirty-first capacitor C31, the fortieth resistor R40, and the second pin of the first switch tube Q1 and then grounded; the third pin of the first switch tube Q1 is electrically connected to the fourth pin of the comparator chip U3 and electrically connected to the twenty-sixth resistor R26 and the twelfth capacitor C12, and the twelfth capacitor C12 is grounded; the third pin of the first switch tube Q1 is electrically connected to the fourth pin of the comparator chip U3 and electrically connected to the twenty-sixth resistor R26 and the twelfth capacitor C12, and the twelfth capacitor C12 is grounded;

[0011] The twenty-sixth resistor R26 is electrically connected to the twenty-fourth resistor R24, and the twenty-fourth resistor R24 ​​is electrically connected to the third pin of the comparator chip U3, the twenty-fifth resistor R25 and the eleventh capacitor C11; the twenty-fifth resistor R25 and the eleventh capacitor C11 are connected in parallel and then grounded; the fourth pin of the comparator chip U3 is electrically connected to the temperature sensing port of the cabinet; the second diode D2 is electrically connected to the switch circuit;

[0012] A fourteenth capacitor C14 and a twenty-ninth capacitor C29 which are arranged in parallel are electrically connected between the second pin and the fifth pin of the comparator chip U3.

[0013] As a further improvement, the switch tube self-locking circuit includes a thirty-fifth resistor R35, one end of the thirty-fifth resistor R35 is electrically connected to the eighth diode D8 and the ninth diode D9, and the other end is electrically connected to the fifteenth capacitor C15, the thirty-fourth resistor R34 and the thirty-third resistor R33; the ninth diode D9 is electrically connected to the fire signal interface; the thirty-third resistor R33 is electrically connected to the first lead of the third switch tube Q3; the fifteenth capacitor C15 and the thirty-fourth resistor R34 are connected in parallel and then electrically connected to the second lead of the third switch tube Q3; the third lead of the third switch tube Q3 is electrically connected to the thirty-first resistor R31, the thirty-first resistor R31 is electrically connected to the thirtieth resistor R30 and the base of the forty-fourth transistor Q44; the thirtieth resistor R30 is electrically connected to the emitter of the forty-fourth transistor Q44, the collector of the forty-fourth transistor Q44 is electrically connected to the thirty-sixth resistor R36, the thirty-sixth resistor R36 is electrically connected to the seventh diode C7, and the seventh diode C7 is electrically connected to the switch circuit.

[0014] As a further improvement, the first switch tube Q1 and the third switch tube Q3 are NMOS tubes or triodes.

[0015] As a further improvement, the main control system is electrically connected to the battery through a battery voltage sampling circuit, and when the battery power is lower than a preset threshold, the battery is charged or the staff is notified to replace the battery.

[0016] As a further improvement, the main control system is electrically connected to the fire equipment interface through the fire equipment interface voltage sampling circuit; when the main control system does not send a signal and senses a signal through the fire equipment interface voltage sampling circuit, it is determined that a false trigger has occurred, and the main control system uploads it to the background to notify the staff to shut down the fire equipment.

[0017] As a further improvement, the main control system is electrically connected to a battery temperature sampling circuit, which is used to detect the temperature of the battery to be charged in the battery compartment of the battery swap cabinet. When the temperature of the battery to be charged is higher than a preset threshold or the temperature speed is higher than a preset threshold, the main control system sends a signal to the fire-fighting equipment to perform a fire-fighting action.

[0018] As a further improvement, the fire sensor includes a smoke sensor, a temperature sensor, an air pressure sensor, a battery voltage detection circuit and a battery temperature detection circuit.

[0019] As a further improvement, the output voltage of the auxiliary power supply is lower than the output voltage of the main power supply.

[0020] Advantages of the present invention:

[0021] 1. There are no special requirements for the cabinet system itself, and it can be directly connected. It can be applied to new products and is compatible with existing products;

[0022] 2. Multiple self-locking systems ensure that the fire-fighting equipment in the cabinet is continuously powered and operates in a fire-fighting state. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a circuit diagram of the existing fire protection system;

[0024] Figure 2 is a schematic diagram of the overall circuit of the present invention;

[0025] Figure 3 is a circuit diagram of a comparator self-locking circuit;

[0026] Figure 4 This is the circuit diagram of the cabinet temperature sensing port;

[0027] Figure 5 Circuit diagram of the switch tube self-locking circuit

[0028] Figure 6 is a circuit diagram of a switch circuit;

[0029] Figure 7 Schematic diagram of the charging circuit. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0031] Example

[0032] like Figure 2 The fire protection circuit with power-off and power-backup self-locking shown in the figure is composed of various interfaces, a step-down circuit, a charging circuit, a switching circuit, a switch tube self-locking circuit, a comparator self-locking circuit, and a unidirectional circuit (such as the diode in the figure).

[0033] There are 4 interfaces. They are: 1. Power interface connected to the output port of the main control power supply (DC power supply converted from external AC power in the cabinet); 2. Battery interface connected to the backup battery; 3. Fire signal interface connected to the fire start power supply output by the main control system; 4. Fire equipment interface connected to the alarm signaler (such as sound and light alarm) and fire circulation power device (such as water pump) in the fire protection system. (Among them, the power supply of the main control system connected to the fire signal interface comes from the main control power supply, such as Figure 2 (shown)

[0034] Buck circuit 1. The buck circuit is used to supply power to the comparator self-locking circuit in the device.

[0035] There is one charging circuit. It is started when the main control power supply charges the backup battery through the power interface when it is not fully charged.

[0036] The switch circuit has 1 circuit. It is a circuit that controls the opening and closing of the battery (through the battery interface) and the fire fighting equipment (through the fire fighting equipment interface).

[0037] There is one switch self-locking circuit. When a fire start signal is transmitted from the fire signal interface, the circuit will lock the signal. Even if the signal becomes a high impedance state or other level signal later, the level will be maintained unchanged at the back end of the circuit.

[0038] The comparator self-locking circuit has 1 path. When the comparator detects that the temperature reaches the threshold, it will trigger the comparator to reverse, and the circuit will lock the signal at the same time. Even if the temperature drops later, it will not cause the comparator to reverse again.

[0039] Specifically:

[0040] 1. When the main control system detects a fire alarm: the main control system outputs a signal (this signal has both signal and power functions, which can meet the power supply of the back-end equipment) to power the fire-fighting device, and also gives a signal to the self-locking circuit. At this time, the backup battery also powers the water pump, but due to the low voltage, the main energy for powering the water pump is still provided by the main control power supply;

[0041] 2. After the first situation occurs, the main control system stops supplying power to the water pump due to uncontrollable factors (such as short circuit, external AC power is cut off). At this time, the switch tube self-locking circuit works (maintaining state), and the backup battery directly supplies power to the water pump; (water pump)

[0042] 3. Due to the existence of uncontrollable factors, the main control system may be damaged before detecting a fire, resulting in failure to give a fire signal. If the cabinet catches fire at this time, causing the temperature sensor in the comparator self-locking circuit to trigger an early warning, the backup battery pack will directly power the fire-fighting equipment to ensure that the cabinet can successfully extinguish the fire.

[0043] Specific as Figure 3 and Figure 4As shown, the CABINET_TEMP terminal of the comparator self-locking circuit is connected to the cabinet temperature sensing port. Since the temperature sensor used is a negative temperature coefficient, in the initial state, the temperature is low. When it is lower than the set threshold, the temperature sensor resistance is relatively large, and the CABINET_TEMP terminal voltage is relatively large. At this time, for U3, when IN->IN+, VOUT outputs a low level, and the G pole of Q1 is at a low level, so Q1 is cut off, and the voltage at the IN- terminal is only controlled by the CABINET_TEMP terminal voltage. When the cabinet temperature rises, the resistance of the temperature sensor decreases. When the temperature rises to the set threshold, the CABINET_TEMP terminal voltage becomes smaller, resulting in IN-<IN+ of U3, and VOUT outputs a high level. At this time, the G pole of Q1 is at a high level, so Q1 is turned on, and then the IN- terminal voltage is directly pulled to 0V. At this time, the IN- terminal voltage is no longer controlled by the CABINET_TEMP terminal voltage. Instead, it becomes a normal 0V state, forcing the IN-<IN+ state of U3 to be permanently established. Correspondingly, VOUT also continuously outputs a high level. Even if the temperature drops later, it will not affect the voltage at the IN- terminal. So it is equivalent to self-locking the output high-level signal.

[0044] like Figure 5 As shown in the figure, the default fire signal FIRE_VDD_SIGNAL of the switch self-locking circuit is low level (invalid state), at this time, the G pole of Q3 is low level, and Q3 is cut off. Therefore, the voltage of Q3 is consistent with BAT_VDD, so Q44 is also cut off, SWITCH_EN and KEEP_VDD are also high impedance (KEEP_VDD is also connected to the G pole of Q3 through a diode D8, and because it is in high impedance state, it will not affect the state of Q3). When the main control board fire signal FIRE_VDD_SIGNAL is high, the G pole of Q3 is also high, Q3 is turned on, and the D pole of Q3 is also pulled from high level to low level, thereby turning on Q44, so the SWITCH_EN output is the same voltage as BAT_VDD. At the same time, the voltage of KEEP_VDD is also the same voltage as BAT_VDD, and is sufficient to turn on Q3, so Q3 will remain in the normal on state, and then Q44 will also remain in the on state, and the SWITCH_EN output will maintain the same voltage as BAT_VDD. Even if the main control board is reset or powered off later, making FIRE_VDD_SIGNAL high impedance or low level, it will no longer affect the SWITCH_EN output and BAT_VDD to maintain the same voltage. So it is equivalent to self-locking the output SWITCH_EN signal.

[0045] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A fire protection circuit with power failure and power backup self-locking, characterized in that: It includes a power interface electrically connected to a main power supply and a battery interface electrically connected to an auxiliary power supply; the power interface and the battery interface of the main power supply are electrically connected to the same step-down circuit, and the step-down circuit is electrically connected to a comparator self-locking circuit; the main power supply is electrically connected to a main control system, the main control system is electrically connected to a fire signal interface, and the fire signal interface is electrically connected to a switch tube self-locking circuit and a fire equipment interface; the switch tube self-locking circuit is electrically connected to a switch circuit, and the switch circuit is electrically connected to a comparator self-locking circuit, a fire equipment interface and a battery interface; The main control system is connected to several fire sensors; Among them, the switch tube self-locking circuit is used to receive the fire start signal transmitted by the fire signal interface. After receiving the fire start signal, the switch tube self-locking circuit makes and maintains the switch circuit in a driving connection state, and maintains the power supply of the main power supply and / or the auxiliary power supply to the fire equipment; The comparator self-locking circuit is used to detect the temperature. When the current temperature exceeds the preset threshold, the comparator of the comparator self-locking circuit is reversed and the output signal is locked, so that the switch circuit is kept in a driving connection state, and the main power supply and / or auxiliary power supply to the fire-fighting equipment are maintained; The fire equipment interface is used to electrically connect fire equipment.

2. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The main power source is low-voltage direct current converted from commercial power, and the auxiliary power source is a battery; the main power source is electrically connected to the auxiliary power source through a charging circuit.

3. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The comparator self-locking circuit comprises a comparator chip (U3), wherein a first pin of the comparator chip (U3) is electrically connected to a twenty-ninth resistor (R29), the twenty-ninth resistor (R29) is electrically connected to a thirty-ninth resistor (R39), a second diode (D2), a twenty-eighth resistor (R28), a fortieth resistor (R40) and one end of a twenty-eighth capacitor (C28), respectively, the twenty-eighth resistor (R28) is electrically connected to a thirty-first capacitor (C31) and a first pin of a first switch tube (Q1); the other end of the twenty-eighth capacitor (C28) is electrically connected to the thirty-first capacitor (C31), the fortieth resistor (R40) and a second pin of the first switch tube (Q1) and then grounded; the third pin of the first switch tube (Q1) is electrically connected to a fourth pin of the comparator chip (U3) and electrically connected to a twenty-sixth resistor (R26) and a twelfth capacitor (C12), and the twelfth capacitor (C12) is grounded; The twenty-sixth resistor (R26) is electrically connected to the twenty-fourth resistor (R24), and the twenty-fourth resistor (R24) is electrically connected to the third pin of the comparator chip (U3), the twenty-fifth resistor (R25) and the eleventh capacitor (C11); the twenty-fifth resistor (R25) and the eleventh capacitor (C11) are connected in parallel and then grounded; the fourth pin of the comparator chip (U3) is electrically connected to the temperature sensing port of the cabinet; the second diode (D2) is electrically connected to the switch circuit; A fourteenth capacitor (C14) and a twenty-ninth capacitor (C29) which are arranged in parallel are electrically connected between the second pin and the fifth pin of the comparator chip (U3).

4. The fire protection circuit with power failure and power backup self-locking as claimed in claim 3, characterized in that: The switch tube self-locking circuit comprises a thirty-fifth resistor (R35), one end of the thirty-fifth resistor (R35) is electrically connected to the eighth diode (D8) and the ninth diode (D9), and the other end is electrically connected to the fifteenth capacitor (C15), the thirty-fourth resistor (R34) and the thirty-third resistor (R33); the ninth diode (D9) is electrically connected to the fire signal interface; the thirty-third resistor (R33) is electrically connected to the first lead of the third switch tube (Q3); the fifteenth capacitor (C15) and the thirty-fourth resistor (R34) are connected in parallel and then electrically connected to the third switch tube ( The third lead of the third switch tube (Q3) is electrically connected to a thirty-first resistor (R31), the thirty-first resistor (R31) is electrically connected to a thirtieth resistor (R30) and the base of a forty-fourth transistor (Q44); the thirtieth resistor (R30) is electrically connected to the emitter of the forty-fourth transistor (Q44), the collector of the forty-fourth transistor (Q44) is electrically connected to a thirty-sixth resistor (R36), the thirty-sixth resistor (R36) is electrically connected to a seventh diode (C7), and the seventh diode (C7) is electrically connected to the switch circuit.

5. The fire protection circuit with power failure and power backup self-locking as claimed in claim 4, characterized in that: The first switch tube (Q1) and the third switch tube (Q3) are NMOS tubes or triodes.

6. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The main control system is electrically connected to the battery through a battery voltage sampling circuit. When the battery power is lower than a preset threshold, the battery is charged or a staff is notified to replace the battery.

7. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The main control system is electrically connected to the fire equipment interface through the fire equipment interface voltage sampling circuit; when the main control system does not send a signal and senses a signal through the fire equipment interface voltage sampling circuit, it is judged that a false trigger has occurred, and the main control system uploads it to the background to notify the staff to shut down the fire equipment.

8. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The main control system is electrically connected to a battery temperature sampling circuit, which is used to detect the temperature of the battery to be charged in the battery compartment of the battery swap cabinet. When the temperature of the battery to be charged is higher than a preset threshold or the temperature speed is higher than a preset threshold, the main control system sends a signal to the fire-fighting equipment to take fire-fighting action.

9. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The fire fighting sensor comprises a smoke sensor, a temperature sensor, an air pressure sensor, a battery voltage sampling circuit and a battery temperature detection circuit.

10. The fire protection circuit with power failure and power backup self-locking as claimed in claim 1, characterized in that: The output voltage of the auxiliary power supply is lower than the output voltage of the main power supply.

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