Emergency lighting system and lighting system

Abstract

The invention provides an emergency lighting system and a lighting system, and the system comprises an impedance detection circuit which detects the impedance between a zero line end and a live line end, so as to output an impedance detection signal; the reference signal generating circuit is used for generating a reference signal according to the voltage of the emergency battery, and the reference signal changes along with the voltage change of the emergency battery; and the emergency control circuit is used for controlling whether the emergency battery supplies power to the illuminating lamp or not according to the impedance detection signal and the reference signal when no alternating current is input. The emergency lighting circuit provided by the invention can generate a reference signal synchronously changing along with the voltage of the emergency battery according to the voltage of the emergency battery, and the reference signal is used as a judgment condition of a high-impedance state and a low-impedance state. Therefore, the influence of the voltage change of the emergency battery on the impedance detection signal is counteracted by the reference signal synchronously changing along with the voltage of the emergency battery, so that the detection precision of the high / low impedance state is improved, and the emergency lighting system is prevented from being started by mistake.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and in particular relates to an emergency lighting system and a lighting system. Background Art

[0002] like Figure 1 As shown, when there is no AC input, a detection signal representing the equivalent impedance between the L line and the N line is collected, and then the detection signal and the reference signal Vref are compared. The reference signal Vref represents the threshold impedance of the high impedance state and the low impedance state. When the detection signal is greater than the reference signal Vref, it indicates that the L line and the N line are in a low impedance state, then the emergency lighting system is controlled to be turned on, and the emergency power supply Vbat supplies power to the load. When the detection signal is less than the reference signal Vref, it indicates that the L line and the N line are in a high impedance state, then the emergency lighting system is controlled to be in a closed state. From the above, it can be seen that the reference signal Vref determines whether the emergency lighting system is turned on. In the prior art, since the voltage of the emergency power supply Vbat varies within a certain range, for example, a lithium battery is about 2.7V-4.25V, and a sodium battery is about 1.5V-3.65V. Therefore, in order to ensure that the emergency lighting system can be turned on normally when the battery voltage is low, the reference signal Vref should be set according to the minimum voltage of the emergency power supply Vbat. This will cause the threshold impedance to increase significantly when the battery voltage is high. The wider range of the threshold impedance increases the difficulty of distinguishing between high and low impedance states, which may cause the emergency lighting system to be turned on by mistake. Summary of the invention

[0003] In order to solve the technical problem of poor detection accuracy of high / low impedance states in the emergency lighting system in the prior art, the present invention provides an emergency lighting system and a lighting system, the emergency lighting system comprising:

[0004] The impedance detection circuit detects the impedance between the neutral line terminal and the live line terminal to output an impedance detection signal;

[0005] A reference signal generating circuit generates a reference signal according to the voltage of the emergency battery, wherein the reference signal changes with the voltage of the emergency battery, and the reference signal represents a threshold impedance for distinguishing a high impedance state from a low impedance state;

[0006] The emergency control circuit controls whether the emergency battery supplies power to the lighting lamp according to the impedance detection signal and the reference signal when there is no AC input, and the positive electrode of the emergency battery is connected to the live wire terminal and the lighting lamp.

[0007] Further, the impedance detection circuit includes: a first resistor and a second resistor connected in sequence between the neutral terminal and the ground terminal, and a voltage at a connection point between the first resistor and the second resistor is the impedance detection signal;

[0008] The reference signal generating circuit controls the change rate of the reference signal according to the first resistor, the second resistor and the threshold impedance.

[0009] Furthermore, the reference signal is in direct proportion to the voltage of the emergency battery, the ratio of the second resistor to the total resistance is a positive proportionality coefficient, and the total resistance is the sum of the first resistor, the second resistor and the threshold impedance.

[0010] Preferably, the reference signal generating circuit comprises a third resistor and a fourth resistor connected in sequence between the emergency battery and the ground terminal, and the voltage at the connection point between the third resistor and the fourth resistor is the reference signal.

[0011] The resistance of the third resistor is N times the sum of the resistance of the first resistor and the threshold impedance, the resistance of the fourth resistor is equal to N times the resistance of the second resistor, and N is a positive integer.

[0012] Preferably, the reference signal generating circuit includes a multiplier, a first input terminal of the multiplier is connected to the emergency battery, a second input terminal receives a proportional coefficient, an output of the multiplier is the reference signal, a ratio of the second resistor to the total resistance is the proportional coefficient, and the total resistance is the sum of the first resistor, the second resistor and the threshold impedance.

[0013] Furthermore, it also includes: an AC input detection circuit, the AC input detection circuit is connected to the neutral line terminal and / or the live line terminal to obtain an input detection signal, and the input detection signal represents whether there is AC input.

[0014] Furthermore, it also includes a high-voltage isolation circuit, which is connected between the emergency battery and the live wire terminal and is used to isolate the AC power from the emergency battery when there is AC power input.

[0015] Furthermore, it also includes an emergency switch, which is connected between the emergency battery and the lighting lamp.

[0016] Furthermore, the emergency control circuit includes:

[0017] A comparison circuit compares the reference signal and the impedance detection signal, and outputs a state signal, wherein the state signal indicates that the neutral terminal and the live terminal are in a high impedance state or a low impedance state;

[0018] The switch control circuit generates a switch control signal according to the state signal when there is no AC input, so as to control the on and off of the emergency switch, wherein the emergency switch is connected between the emergency battery and the lighting lamp.

[0019] A lighting system comprises a voltage conversion circuit and a lighting lamp, wherein the voltage conversion circuit converts alternating current to power the lighting lamp, and also comprises the emergency lighting system described above.

[0020] The emergency lighting circuit proposed by the present invention generates a reference signal that changes synchronously with the emergency battery voltage according to the voltage of the emergency battery, so as to serve as a judgment condition for the high impedance state and the low impedance state. Therefore, the influence of the voltage change of the emergency battery on the impedance detection signal is offset by the reference signal that changes synchronously with the emergency battery voltage, thereby improving the detection accuracy of the high / low impedance state and avoiding the emergency lighting system from being turned on by mistake. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is prior art;

[0022] Figure 2 A structural diagram of the emergency lighting system proposed by the present invention;

[0023] Figure 3 is a circuit diagram of the emergency lighting system in the first embodiment;

[0024] Figure 4 is a circuit diagram of an emergency lighting system in a second embodiment;

[0025] Figure 5 This is a structural diagram of the lighting system proposed by the present invention. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0027] like Figure 1 As shown, when there is no AC input, the detection signal Vcs representing the equivalent impedance between the L line and the N line is collected, and then the detection signal Vcs is compared with the reference signal Vref, and the reference signal Vref represents the threshold impedance of the high impedance state and the low impedance state. When the detection signal Vcs is greater than the reference signal Vref, it means that the L line and the N line are in a low impedance state, and at this time, the emergency lighting system needs to be controlled to be turned on, and the emergency power supply Vbat supplies power to the load; when the detection signal Vcs is less than the reference signal Vref, it means that the L line and the N line are in a high impedance state, and at this time, the emergency lighting system needs to be controlled to be in a closed state.

[0028] Among them, the reference signal Vref determines whether the emergency lighting system is turned on. In the prior art, since the voltage of the emergency power supply Vbat varies within a certain range, such as about 2.7V-4.25V for lithium batteries and about 1.5V-3.65V for sodium batteries, in order to ensure that the emergency lighting system can be turned on normally when the battery voltage is low, the reference signal Vref will be set according to the minimum voltage of the emergency battery Vbat. Therefore, the smaller the minimum voltage of the emergency power supply Vbat, the smaller the threshold impedance represented by the set reference signal Vref. However, this causes the threshold impedance to increase significantly when the battery voltage is high, and the wider range of the threshold impedance increases the difficulty of distinguishing between high / low impedance states, which may cause the emergency lighting system to be turned on by mistake.

[0029] Therefore, the present invention proposes an emergency lighting circuit, which further optimizes the above-mentioned method of setting the reference signal Vref to improve the detection accuracy of the high / low impedance state and avoid the emergency lighting system from being turned on by mistake. Figure 2 As shown, the emergency lighting circuit includes:

[0030] The impedance detection circuit detects the impedance between the neutral line terminal and the live line terminal to output an impedance detection signal representing the impedance between the neutral line and the live line;

[0031] The reference signal generating circuit generates a reference signal that changes synchronously with the voltage of the emergency battery according to the voltage of the emergency battery, and the reference signal represents the threshold impedance of the high impedance state and the low impedance state;

[0032] The emergency control circuit controls whether the emergency battery supplies power to the lighting lamp according to the impedance detection signal and the reference signal when there is no AC input, and the emergency battery is connected to the live wire end and the lighting lamp;

[0033] In summary, the emergency lighting circuit proposed in the present invention generates a reference signal that changes synchronously with the emergency battery voltage according to the voltage of the emergency battery, as a judgment condition for the high impedance state and the low impedance state. Therefore, the influence of the voltage change of the emergency battery on the impedance detection signal is offset by the reference signal that changes synchronously with the emergency battery voltage, thereby improving the detection accuracy of the high / low impedance state and avoiding the emergency lighting system from being turned on by mistake.

[0034] Further, such as Figure 3 and Figure 4 As shown, the impedance detection circuit includes: a first resistor R1 and a second resistor R2 connected in sequence between the neutral line terminal and the ground terminal, the voltage at the connection point between the first resistor R1 and the second resistor R2 is an impedance detection signal, and the reference signal generating circuit controls the change rate of the reference signal according to the first resistor, the second resistor and the threshold impedance, and the reference signal is a voltage signal.

[0035] Furthermore, the reference signal is in direct proportion to the voltage of the emergency battery, the ratio of the second resistor to the total resistance is a positive proportionality coefficient, and the total resistance is the sum of the first resistor, the second resistor and the threshold impedance.

[0036] Specifically, the emergency lighting circuit proposed by the present invention is further explained below with reference to specific embodiments.

[0037] Preferably, in the first embodiment, as Figure 2 and Figure 3 As shown, the positive electrode of the emergency battery is connected to the live wire terminal through a high-voltage isolation circuit, and is connected to the lighting load through an emergency switch S2. The impedance detection circuit includes a first resistor R1 and a second resistor R2 connected in series between the neutral terminal and the ground terminal, wherein the voltage at the connection point between the first resistor R1 and the second resistor R2 is the impedance detection signal Vcs; the reference signal generation circuit includes a third resistor R3 and a fourth resistor R4 connected in series between the positive electrode of the emergency battery and the ground terminal, wherein the voltage at the connection point between the third resistor R3 and the fourth resistor R4 is the reference signal Vref. Further, the resistance of the third resistor R3 is the sum of the resistance of the first resistor R1 and the threshold impedance, and the resistance of the fourth resistor R4 is equal to the resistance of the second resistor R2. Or the resistance of the third resistor R3 is N times the sum of the resistance of the first resistor R1 and the threshold impedance, and the resistance of the fourth resistor R4 is N times the resistance of the second resistor R2, and N is a positive integer. The emergency control circuit includes a comparison circuit and a switch control circuit. The comparison circuit compares the reference signal Vref and the impedance detection signal Vcs to output a state signal. The state signal indicates that the neutral line terminal and the live line terminal are in a high impedance state or a low impedance state. The switch control circuit generates a switch control signal according to the state signal to control the on and off of the emergency switch when there is no AC input, so as to control whether the emergency battery supplies power to the lighting load.

[0038] Further, the comparison circuit includes a comparator U1, the reverse input terminal of the comparator U1 is connected to the connection point of the third resistor R3 and the fourth resistor R4, and the forward input terminal is connected to the connection point of the first resistor R1 and the second resistor R2; the switch control circuit includes an RS trigger and a drive circuit, the AC input detection signal generated by the AC input detection circuit and the state signal output by the comparator U1 are connected to the set end of the RS trigger after being processed by the AND gate, and the drive circuit generates a switch control signal according to the output signal of the RS trigger. Specifically, when the detection signal Vcs is greater than the reference signal Vref, the comparator U1 outputs a state signal in a high level state, and the state signal in a high level state indicates that the L line and the N line are in a low impedance state; when the detection signal Vcs is less than the reference signal Vref, the comparator U1 outputs a state signal in a low level state, and the state signal in a low level state indicates that the L line and the N line are in a high impedance state. The state signal in the high level state and the AC input detection signal indicating that there is no AC input are logically processed to generate a corresponding output signal through the RS trigger, and the drive circuit generates a switch control signal accordingly to control the emergency switch S2 to be turned on, so that the emergency power supply supplies power to the lighting lamp.

[0039] In summary, when the AC input detection signal indicates that there is no AC input, assuming that the equivalent impedance between the neutral terminal and the live terminal is R L-N , then the impedance detection signal Vcs of the impedance detection circuit satisfies: Vbat is the voltage of the emergency battery. At this time, the reference signal Vref satisfies: R th is the threshold impedance. Therefore, when the neutral terminal and the live terminal are in a high impedance state or a low impedance state, if the emergency battery voltage changes, the impedance detection signal Vcs and the reference signal Vref will change accordingly. However, because the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the threshold impedance R th They are all matched with each other, so the change rate of the impedance detection signal Vcs is certain, and the impedance detection signal Vcs at any value corresponds to the equivalent impedance R L-N Similarly, the rate of change of the reference signal Vref is constant, and any value of the reference signal Vref corresponds to the threshold impedance R th Therefore, the influence of the voltage change of the emergency battery on the detected equivalent impedance is offset by the corresponding matching change of the reference signal Vref, thereby improving the detection accuracy of the high / low impedance state. That is, the emergency lighting system can accurately determine whether the neutral terminal and the live terminal are in a high impedance state or a low impedance state according to the impedance detection signal Vcs and the reference signal Vref, thereby controlling whether the emergency lighting system is turned on.

[0040] Preferably, in the second embodiment, as Figure 2 and Figure 4 As shown, the positive electrode of the emergency battery is connected to the live wire terminal through a high-voltage isolation circuit, and is connected to the lighting load through an emergency switch S2. The impedance detection circuit includes a first resistor R1 and a second resistor R2 which are sequentially connected in series between the neutral wire terminal and the ground terminal, wherein the voltage at the connection point of the first resistor R1 and the second resistor R2 is the impedance detection signal Vcs; the reference signal generating circuit includes a multiplier, wherein the first input terminal of the multiplier is connected to the emergency battery, and the second input terminal receives a positive proportional coefficient K, and the output of the multiplier is a reference signal Vref, i.e., the first input terminal of the multiplier receives Vbat, and the second input terminal receives Vcs. Then the reference signal output by the multiplier satisfies: Similarly, the emergency control circuit includes a comparison circuit and a switch control circuit. The comparison circuit compares the reference signal Vref and the impedance detection signal Vcs to output a state signal. The state signal indicates that the neutral terminal and the live terminal are in a high impedance state or that the neutral terminal and the live terminal are in a low impedance state. The switch control circuit generates a switch control signal according to the state signal to control the on and off of the emergency switch when there is no AC input, so as to control whether the emergency battery supplies power to the lighting lamp load. The comparison circuit includes a comparator U1, the reverse input end of the comparator U1 is connected to the connection point of the third resistor R3 and the fourth resistor R4, and the forward input end is connected to the output end of the multiplier. The switch control circuit includes an RS trigger and a drive circuit. The AC input detection signal generated by the AC input detection circuit and the state signal output by the comparator U1 are connected to the set end of the RS trigger after being processed by the AND gate. The drive circuit generates a switch control signal according to the output signal of the RS trigger.

[0041] As in the first embodiment, when the AC input detection signal indicates that there is no AC input, it is assumed that the equivalent impedance between the neutral terminal and the live terminal is R L-N , then the impedance detection signal Vcs of the impedance detection circuit satisfies: Vbat is the voltage of the emergency battery. At this time, the reference signal Vref satisfies: R th Therefore, when the neutral terminal and the live terminal are in a high impedance state or a low impedance state, if the emergency battery voltage changes, the impedance detection signal Vcs and the reference signal Vref will change accordingly, and the changes of the impedance detection signal Vcs and the reference signal Vref are also matched with each other. The change rate of the impedance detection signal Vcs is determined, and the impedance detection signal Vcs at any value corresponds to the equivalent impedance R L-N The change rate of the reference signal Vref is constant, and the reference signal Vref at any value corresponds to the threshold impedance R thTherefore, the influence of the voltage change of the emergency battery on the detected equivalent impedance is offset by the corresponding matching change of the reference signal Vref, thereby improving the detection accuracy of the high and low impedance states. That is, the emergency lighting system can accurately determine whether the neutral terminal and the live terminal are in a high impedance state or a low impedance state according to the impedance detection signal Vcs and the reference signal Vref, thereby controlling whether the emergency lighting system is turned on.

[0042] Further, such as Figure 3 and Figure 4 As shown, the AC input detection circuit in the emergency lighting system proposed above is connected to the neutral terminal and / or the live terminal to obtain an input detection signal, and the input detection signal indicates whether there is AC input. Specifically, the AC input detection circuit includes: a comparator U2 and a timer, the reverse input terminal of the comparator U2 receives the impedance detection signal Vcs, and the forward input terminal receives the second reference signal Vref', the output terminal of the comparator U2 is connected to the input terminal of the timer, and the timer outputs an AC input detection signal. When the timer receives the comparison result of the comparator U2 and it is continuously in a high level state and maintained for a period of time, it is determined that there is no AC input, and the negative signal of the comparator U2 is used to reset the RS trigger, and the AC input detection signal output by the timer and the status signal are processed by an AND gate.

[0043] Furthermore, the high voltage isolation circuit isolates the connection between the AC input terminal and the emergency battery when there is AC input. Figure 3 or Figure 4 As shown, in one embodiment, the high-voltage isolation circuit includes an isolation switch S1, and the isolation switch S1 is controlled to be on and off according to an input detection signal. When the input detection signal indicates that there is no AC input, the isolation switch S1 is turned on.

[0044] The present invention also provides a lighting system, such as Figure 5 As shown, the lighting system includes a voltage conversion circuit, a lighting lamp and the above emergency lighting system, and the voltage conversion circuit converts the alternating current to power the lighting lamp.

[0045] It should be noted that the specific implementation and corresponding illustrations given are merely a way of describing the implementation method of the present invention, and do not limit the specific structure of the implementation scheme of the present invention. Various changes or modifications can be made to these implementation schemes without departing from the principle and essence of the present invention, but these changes and modifications fall within the scope of protection of the present invention.

[0046] Although the embodiments are described and illustrated separately above, some common technologies are involved. It is the opinion of ordinary technicians in this field that the embodiments can be replaced and integrated. If the content is not clearly recorded in one of the embodiments, reference can be made to another recorded embodiment.

[0047] The above-described implementation methods do not constitute a limitation on the protection scope of the technical solution. Any modification, equivalent replacement and improvement made within the spirit and principle of the above-described implementation methods shall be included in the protection scope of the technical solution.

Claims

1. An emergency lighting circuit, characterized in that: include: The impedance detection circuit detects the impedance between the neutral line terminal and the live line terminal to output an impedance detection signal; A reference signal generating circuit generates a reference signal according to the voltage of the emergency battery, wherein the reference signal changes with the voltage of the emergency battery, and the reference signal represents a threshold impedance for distinguishing a high impedance state from a low impedance state; The emergency control circuit controls whether the emergency battery supplies power to the lighting lamp according to the impedance detection signal and the reference signal when there is no AC input, and the positive electrode of the emergency battery is connected to the live wire terminal and the lighting lamp.

2. The emergency lighting system according to claim 1, characterized in that: The impedance detection circuit comprises: a first resistor and a second resistor connected in sequence between a neutral terminal and a ground terminal, wherein a voltage at a connection point between the first resistor and the second resistor is the impedance detection signal; The reference signal generating circuit controls the change rate of the reference signal according to the first resistor, the second resistor and the threshold impedance.

3. The emergency lighting system according to claim 2, characterized in that: The reference signal is in direct proportion to the voltage of the emergency battery, the ratio of the second resistor to the total resistance is a direct proportionality coefficient, and the total resistance is the sum of the first resistor, the second resistor and the threshold impedance.

4. The emergency lighting system according to claim 2 or 3, characterized in that: The reference signal generating circuit comprises a third resistor and a fourth resistor connected in sequence between the emergency battery and the ground terminal, and the voltage at the connection point between the third resistor and the fourth resistor is the reference signal. The resistance of the third resistor is N times the sum of the resistance of the first resistor and the threshold impedance, the resistance of the fourth resistor is equal to N times the resistance of the second resistor, and N is a positive integer.

5. The emergency lighting system according to claim 2 or 3, characterized in that: The reference signal generating circuit includes a multiplier, a first input terminal of the multiplier is connected to the emergency battery, a second input terminal receives a proportional coefficient, an output of the multiplier is the reference signal, a ratio of the second resistor to the total resistance is the proportional coefficient, and the total resistance is the sum of the first resistor, the second resistor and the threshold impedance.

6. The emergency lighting system according to claim 1, characterized in that: Also includes: An AC input detection circuit is connected to the neutral terminal and / or the live terminal to obtain an input detection signal, wherein the input detection signal indicates whether there is AC input.

7. The emergency lighting system according to claim 1, characterized in that: It also includes a high-voltage isolation circuit, which is connected between the emergency battery and the live wire terminal and is used to isolate the AC power from the emergency battery when there is AC power input.

8. The emergency lighting system according to claim 1, characterized in that: An emergency switch is also included, and the emergency switch is connected between the emergency battery and the lighting lamp.

9. The emergency lighting system according to claim 1 or 8, characterized in that: The emergency control circuit comprises: A comparison circuit compares the reference signal and the impedance detection signal, and outputs a state signal, wherein the state signal indicates that the neutral terminal and the live terminal are in a high impedance state or a low impedance state; The switch control circuit generates a switch control signal according to the state signal when there is no AC input, so as to control the on and off of the emergency switch, wherein the emergency switch is connected between the emergency battery and the lighting lamp.

10. A lighting system, comprising a voltage conversion circuit and a lighting lamp, wherein the voltage conversion circuit converts alternating current to power the lighting lamp, characterized in that: It also includes the emergency lighting system according to any one of claims 1 to 9.

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