A super power-saving standby management circuit for emergency lighting fixtures

Abstract

The present invention discloses a super power-saving standby management circuit for emergency lighting power supply, comprising an AC / DC power supply, a charging circuit, a switch signal acquisition circuit, an LED constant current drive circuit and an LED light source, wherein the LED constant current drive circuit comprises output terminals VD+ and VD‑, the AC / DC power supply comprises output terminals V1+ and V1‑, and further comprises a single-chip microcomputer MCU1, a rechargeable battery circuit, an electric energy switching circuit and a charging detection circuit, wherein the single-chip microcomputer MCU1 comprises a pin VCC, a pin PJ, a pin PA, a pin PD, a pin PW and a common pin VSS, and an operation program for automatically judging whether it is necessary to enter a super power-saving standby working mode, and automatically detecting a mains switch light signal and whether a mains power outage requires power supply from a rechargeable battery.

Description

Technical Field

[0001] The invention belongs to the field of electronic information technology, and in particular relates to a super power-saving standby management circuit for emergency lighting fixtures. Background Art

[0002] Emergency lighting refers to lighting facilities that are used only under abnormal conditions, including backup lighting, evacuation lighting, and safety lighting. When a disaster occurs in a civil building, emergency lighting and evacuation indicator lighting are particularly important. When the external power supply is interrupted, the people in the building quickly and safely evacuate the disaster area, and the emergency lighting system in the building plays a major role. It is very important to design emergency lighting that is safe, reliable, technologically advanced, and economically reasonable. There are many technical indicators to measure emergency lighting, such as the continuous lighting time, power, and luminous flux of the emergency power supply, but users often overlook an important technical indicator - standby current. When the emergency lighting fixture is installed with a battery pack, there is no need for the LED light source to work and light up. At this time, part of the circuit has begun to enter the standby working state. The power consumption current is called standby current.

[0003] At present, emergency lights consume a lot of power when in standby mode, usually with a standby current loss of several milliamperes to more than ten milliamperes, or even tens of milliamperes. From the time a product leaves the factory to the time it is actually put into use by the customer, the intermediate turnover storage and construction usually takes several months or even more than a year. At this time, the rechargeable battery will cause serious power loss, and even cause irreversible charging failure of the rechargeable battery. In order to solve this problem, there are two traditional solutions: one is to disassemble the rechargeable batteries and pack them separately, and then install the rechargeable batteries during construction; the other is to install a switch on the emergency lighting fixture, disconnect the rechargeable battery connection before leaving the factory, and then connect the power supply during construction. However, if the time from construction to power-on is too long, the rechargeable battery will still cause irreversible charging failure. Summary of the invention

[0004] The present invention provides a super power-saving standby management circuit for emergency lighting fixtures, which is used to solve the problem of long-term standby of rechargeable batteries of emergency lighting fixtures. The super power-saving standby management circuit includes an AC / DC power supply, a charging circuit, a switch signal acquisition circuit, an LED constant current drive circuit and an LED light source, the LED constant current drive circuit includes output terminals VD+ and VD-, the AC / DC power supply includes output terminals V1+ and V1-, and also includes a single-chip microcomputer MCU1, a rechargeable battery circuit, an electric energy switching circuit, and a charging detection circuit. The single-chip microcomputer MCU1 includes a pin VCC, a pin PJ, a pin PA, a pin PD, a pin PW and a common pin VSS. The single-chip microcomputer MCU1 is provided with an operation program for automatically judging whether it is necessary to enter a super power-saving standby working mode, automatically detecting a mains switch light signal and whether a mains power outage requires a rechargeable battery to supply power.

[0005] Preferably, the rechargeable battery circuit includes a diode D1, a rechargeable battery BT1, an output terminal V2+, a negative electrode BAT- and a positive electrode BTA+ of the rechargeable battery, and an output terminal V2-. The positive electrode of the diode D1 is connected to the output terminal V2+ of the charging circuit, the negative electrode of the diode D1 is connected to the negative electrode BAT- of the rechargeable battery, and the negative electrode BAT- of the rechargeable battery is connected to the output terminal V2- of the charging circuit. The rechargeable battery circuit is used to provide power for emergency lighting and prevent backflow of current into the charging circuit.

[0006] Preferably, the electric energy switching circuit includes a diode D2, a relay J1 with two sets of normally closed and normally open, a transistor Q1, resistors R1 and R2, the positive electrode of the diode D2 is connected to the rechargeable battery BTA+, the negative electrode of the diode D2 is connected to the collector c of the transistor Q1, both ends of the coil of the relay J1 with two sets of normally closed and normally open are connected in parallel with the diode D2, the base electrode b of the transistor Q1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the pin PJ of the circuit microcontroller MCU1, the base electrode b of the transistor Q1 is connected to one end of the resistor R2, the other end of the resistor R2 ... The common pins 1 and 4 of the double-group normally closed and normally open relay J1 are respectively connected to the output terminals VD+ and VD- of the LED constant current drive circuit, the normally closed pins 3 and 6 of the double-group normally closed and normally open relay J1 are respectively connected to the output terminals V1+ and V1- of the AC / DC power supply, the normally open pins 2 and 5 of the double-group normally closed and normally open relay J1 are respectively connected to the positive electrode BAT+ and the negative electrode BAT- of the rechargeable battery, and the power switching circuit is used for power switching between mains power supply and rechargeable battery power supply.

[0007] Preferably, the charging detection circuit includes a diode D3, resistors R3 and R4, the positive electrode of the diode D3 is connected to the output terminal V2+ of the charging battery circuit, the negative electrode of the diode D3 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the pin PD of the microcontroller MCU1, one end of the resistor R4 is connected to the pin PD of the microcontroller MCU1, and the other end of the resistor R4 is connected to the negative electrode BTA- of the charging battery, and the charging detection circuit is used to detect whether there is AC power and AC power wake-up.

[0008] Preferably, the operation program is set in the single-chip microcomputer MCU1 in accordance with the following principle: when the single-chip microcomputer MCU1 program detects that it is necessary to enter the super power-saving standby working mode, the single-chip microcomputer MCU1 first turns off the power switching circuit through the pin PJ, the single-chip microcomputer MCU1 turns off the charging detection circuit through the pin PD, and the single-chip microcomputer MCU1 turns off the LED constant current drive circuit through the pin PW, so that all peripheral circuits of the single-chip microcomputer MCU1 are in a power-off state, and the single-chip microcomputer MCU1 enters the super power-saving standby working mode; if the charging detection circuit detects that charging is in progress, the single-chip microcomputer MCU1 first turns on the power switching circuit through the pin PJ, the single-chip microcomputer MCU1 turns on the charging detection circuit through the pin PD, and the single-chip microcomputer MCU1 enables the LED constant current drive circuit through the pin PW, and at this time the single-chip microcomputer MCU1 enters the normal working mode.

[0009] The beneficial effects of the circuit of the present invention are:

[0010] The circuit of the present invention reduces the overall standby current to within a few microamperes, or even below 1 microampere, by setting a hardware circuit and cooperating with the software operation of the single-chip computer MCU1. The power consumption of the standby circuit of the traditional emergency lighting lamp can reach several milliamperes to more than ten milliamperes, or even tens of milliamperes. Compared with this, the power consumption is reduced by thousands to tens of thousands times. Due to the super power-saving standby current, when the rechargeable battery is directly installed in the interior of the emergency lighting fixture, the technical problem of permanent failure of the rechargeable battery due to excessive standby current is solved, which is beneficial to the operation and maintenance of the product; at the same time, the rechargeable battery can be installed in the emergency lighting fixture when it leaves the factory, which solves the problem of complex on-site construction, is beneficial to on-site construction management, improves construction efficiency, and avoids lamp failures caused by uneven installation levels. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The present invention is a schematic diagram of a super power-saving standby management circuit for emergency lighting fixtures.

[0012] Figure 2 The present invention is a single chip microcomputer operation program flow chart of a super power saving standby management circuit for emergency lighting fixtures.

[0013] Reference numerals: 100 - charging battery circuit; 200 - power switching circuit; 300 - charging detection circuit; DETAILED DESCRIPTION

[0014] The circuit of the present invention is further described below in conjunction with the accompanying drawings. Figure 1 and Figure 2As shown, a super power saving standby management circuit for emergency lighting power supply includes an AC / DC power supply, a charging circuit, a switch signal acquisition circuit, an LED constant current drive circuit and an LED light source, wherein the LED constant current drive circuit includes output terminals VD+ and VD-, the AC / DC power supply includes output terminals V1+ and V1-, and also includes a single-chip microcomputer MCU1, a rechargeable battery circuit 100, an energy switching circuit 200, and a charging detection circuit 300. The single-chip microcomputer MCU1 includes a pin VCC, a pin PJ, a pin PA, a pin PD, a pin PW and a common pin VSS. The single-chip microcomputer MCU1 is provided with an operation program for automatically judging whether it is necessary to enter a super power saving standby working mode, automatically detecting a mains switch light signal and whether a rechargeable battery is required for power supply when the mains is out of power.

[0015] like Figure 1 and Figure 2 As shown, when the mains is connected: when there is mains input, the mains is connected from both ends of L and N, and is divided into two mains, one of which supplies power to the AC / DC power supply, and the AC / DC power supply outputs a group of DC power supplies V1+ and V1-, and the DC power supplies V1+ and V1- are split into two, one of which is a DC power supply V1+ and V1- to the charging circuit, and the charging circuit outputs a group of V2+ and V2-, which are charged to the rechargeable battery BT1 through the diode D1, and at the same time, the rechargeable battery BT1 supplies power to the pins VCC and VSS of the microcontroller MCU1, and the microcontroller MCU1 enters the working state; in addition, V2+ is simultaneously connected to the positive electrode of the diode D3, and after the voltage is divided by the diode D3 and the resistors R3 and R4, a high-level signal is provided to the pin PD of the microcontroller MCU1, and the pin PJ of the microcontroller MCU1 outputs a low-level signal, so that the transistor Q1 loses power and is in the cut-off state. Another DC power source V1+, V1- flows to common contacts 1 and 4 through normally closed contacts 3 and 6 of relay J1 to supply power to the LED constant current drive circuit.

[0016] Another mains power supply passes through the peripheral switch S1. If the switch S1 is in the closed state at this time, the switch signal acquisition circuit is powered to make it work normally, and the signal output terminal VS+ is low / high, and the level of the pin PA of the microcontroller MCU1 will also be pulled to a low / high level. If the pin PA of the microcontroller MCU1 is defined as a low / high level to represent a light-on signal, the microcontroller MCU1 outputs a high / low level from the pin PW of the microcontroller MCU1 to the control signal enable terminal VP+ of the LED constant current drive circuit through a built-in operation program, so that the enable terminal VP+ is high / low. If the high / low level of the enable terminal VP+ is defined as a normal working point Light up the LED light source. Assuming that the city power is off at this time, the pin PD of the single-chip microcomputer MCU1 is low level, and the pin PJ of the single-chip microcomputer MCU1 will output a high level, driving the transistor Q1 through the resistor R1, so that the transistor Q1 is in the conducting state, and then causing the relay J1 to work, resulting in the normally open contacts 2 and 5 connecting the positive and negative poles BAT+ and BAT- of the rechargeable battery, and supplying power to the LED constant current drive circuit through the common contacts 1 and 4 of the relay J1. The single-chip microcomputer MCU1 outputs a high level to the control signal enable terminal VP+ of the LED constant current drive circuit through the pin PW, so that it works normally and lights up the LED light source. At this time, it is an emergency lighting state, which is completely powered by the rechargeable battery. At this time, the single-chip microcomputer MCU1 will monitor the voltage of the rechargeable battery. If the voltage is lower than the set value, the built-in calculation program of the single-chip microcomputer MCU1 executes the super power saving standby working mode.

[0017] When the switch S1 is in the off state, the switch signal acquisition circuit is in the power-off state, and the level is released through the signal output terminal VS+. The level of the VS+ will be pulled to a high level / low level by the pin PA of the single-chip microcomputer MCU1 to indicate a light-off signal. The single-chip microcomputer MCU1 uses the built-in calculation program and outputs a low level / high level from the pin PW to the control signal enable terminal VP+ of the LED constant current drive circuit, so that the enable terminal VP+ becomes a low level / high level. If the low level / high level of the enable terminal VP+ is defined as prohibiting operation, the LED light source will not light up.

[0018] like Figure 1 and Figure 2As shown, when a rechargeable battery is installed and the mains power is not connected: the cathode of the diode D1 of the rechargeable battery circuit (100) is connected to the positive terminal BAT+ of the rechargeable battery, so as to prevent the rechargeable battery from backflowing current into the charging circuit. The rechargeable battery supplies power to the single-chip microcomputer MCU1. When the single-chip microcomputer MCU1 is just powered on, it first performs an initialization program, and then starts operation through the built-in program, first through the pin PD. If the pin PD is detected to be at a low level, it means that there is no mains power. Then the single-chip microcomputer MCU1 briefly outputs a high level through the pin PJ, and drives the transistor Q1 through the resistor R1, so that the transistor Q1 is in a conducting state. The relay J1 works, causing the normally open contacts 2 and 5 to connect the positive and negative electrodes BAT+ and BAT- of the rechargeable battery, and then the common contacts 1 and 4 of the relay J1 are connected to the LED constant current drive circuit. The single-chip microcomputer MCU1 outputs a high level through the pin PW, and the control signal enable terminal VP+ of the LED constant current drive circuit makes it work normally to light up the LED light source. At the same time, the built-in calculation program of the single-chip microcomputer MCU1 enters the countdown; when the countdown reaches zero, the output of the pin PJ of the single-chip microcomputer MCU1 becomes a low level, and the transistor Q1 loses power and is in the cut-off state. At this time, the relay J1 is released, causing the normally open contacts 2 and 5 to disconnect from the positive and negative electrodes BAT+ and BAT- of the rechargeable battery, so that the LED constant current drive circuit loses power, and the LED light source does not light up. The built-in calculation program of the single-chip microcomputer MCU1 executes the power-down mode. At this time, only the single-chip microcomputer MCU1 in the entire circuit maintains the lowest operating current, and usually consumes only a few microamperes, or even less than 1uA, to achieve the purpose of minimum power saving.

[0019] like Figure 1 and Figure 2 As shown, the working principle of the circuit of the present invention entering the power-down mode is that when the circuit of the present invention enters the power-down mode, the pin PD of the single-chip microcomputer MCU1 is in a low-level standby wake-up state, and the built-in program sets the pin PD to a high level to wake up the single-chip microcomputer MCU1 to continue working, and sets PD to a low level to not wake up and continue in the power-down mode. If the mains is connected at this time, the pin PD of the single-chip microcomputer MCU1 becomes a high level, and the single-chip microcomputer MCU1 is awakened to continue working.

Claims

1. A super power saving standby management circuit for emergency lighting fixtures, characterized in that: The invention comprises an AC / DC power supply, a charging circuit, a switch signal acquisition circuit, an LED constant current drive circuit and an LED light source. The LED constant current drive circuit comprises output terminals VD+ and VD-, the AC / DC power supply comprises output terminals V1+ and V1-, and further comprises a single chip microcomputer MCU1, a charging battery circuit (100), an electric energy switching circuit (200) and a charging detection circuit (300). The electric energy switching circuit (200) comprises a diode D2, a relay J1 with two groups of normally closed and normally open relays, a transistor Q1, resistors R1 and R2. The single chip microcomputer MCU1 comprises a pin VCC, a pin PJ, a pin PA, a pin PD, a pin PW and a common pin VSS. An operation program is arranged in the single chip microcomputer MCU1, and the operation program has the functions of automatically judging whether to enter a super power saving standby working mode, automatically detecting a mains switch light signal and whether to start the rechargeable battery power supply when the mains power is cut off.

2. The super power saving standby management circuit for emergency lighting fixtures as claimed in claim 1, characterized in that: The rechargeable battery circuit (100) comprises a diode D1, a rechargeable battery BT1, an output terminal V2+, a negative electrode BAT- and a positive electrode BTA+ of the rechargeable battery, and an output terminal V2-. The positive electrode of the diode D1 is connected to the output terminal V2+ of the charging circuit, the negative electrode of the diode D1 is connected to the negative electrode BAT- of the rechargeable battery, and the negative electrode BAT- of the rechargeable battery is connected to the output terminal V2- of the charging circuit. The rechargeable battery circuit (100) is used to provide electric energy for emergency lighting and prevent current from flowing back into the charging circuit.

3. The super power saving standby management circuit of an emergency lighting fixture as claimed in claim 2, characterized in that: The positive electrode of the diode D2 is connected to the rechargeable battery BTA+, the negative electrode of the diode D2 is connected to the collector c of the transistor Q1, the two ends of the coil with the double-group normally closed and normally open relay J1 are connected in parallel with the diode D2, the base electrode b of the transistor Q1 is connected to one end of the resistor R1, the other end of the resistor R1 is connected to the pin PJ of the circuit microcontroller MCU1, the base electrode b of the transistor Q1 is connected to one end of the resistor R2, the other end of the resistor R2 is connected to the rechargeable battery BAT-, the emitter e of the transistor Q1 is connected to the collector c of the transistor Q1, and the two ends of the coil with the double-group normally closed and normally open relay J1 are connected in parallel with the diode D2. The common pins 1 and 4 of the double-group normally closed and normally open relay J1 are respectively connected to the output terminals VD+ and VD- of the LED constant current drive circuit, the normally closed pins 3 and 6 of the double-group normally closed and normally open relay J1 are respectively connected to the output terminals V1+ and V1- of the AC / DC power supply, and the normally open pins 2 and 5 of the double-group normally closed and normally open relay J1 are respectively connected to the positive electrode BAT+ and the negative electrode BAT- of the rechargeable battery. The power switching circuit (200) is used for power switching between mains power supply and rechargeable battery power supply.

4. The super power saving standby management circuit for emergency lighting fixtures as claimed in claim 3, characterized in that: The charging detection circuit (300) comprises a diode D3, resistors R3 and R4, the positive electrode of the diode D3 is connected to the output terminal V2+ of the charging battery circuit (100), the negative electrode of the diode D3 is connected to one end of the resistor R3, the other end of the resistor R3 is connected to the pin PD of the single-chip microcomputer MCU1, one end of the resistor R4 is connected to the pin PD of the single-chip microcomputer MCU1, and the other end of the resistor R4 is connected to the negative electrode BTA- of the charging battery. The charging detection circuit (300) is used to detect whether there is mains power and mains power wake-up.

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