Switch control circuit, single lamp monitoring device, lamp and system

Abstract

The present invention discloses a switch control circuit, a single-lamp monitoring device, a lighting fixture and a system. In the switch control circuit, two transistors with the same polarity, a voltage limiting circuit, a unidirectional conduction circuit, a capacitor and an input circuit are provided. The switch control circuit can enable the light-emitting elements connected in series to be safely and quickly controlled to turn on and off when excited by alternating current for lighting.

Description

Technical Field

[0001] The present invention relates to a switch control circuit, a single lamp monitoring device, a lamp and a system. Background Art

[0002] The on-off state of an airport navigation aid lamp is controlled by a switch control circuit. Chinese Utility Model Patent CN204482093U proposes an aid navigation lamp segmented control device, so as to selectively control a lamp segment to turn on or off. In related technologies, a light-emitting element is arranged in an aid navigation lamp fixture, and the on or off of each light-emitting element can also be independently controlled. Chinese Patent Application CN1719959A proposes an airport aid navigation LED lamp dimming system, which can realize independent control of a single LED lamp.

[0003] With the continuous development of navigation aid lamp technology, 2 or more light-emitting elements are arranged in a single aid navigation lamp fixture. For example, 2 light-emitting elements are arranged in a single aid navigation lamp fixture, and the on of one of the 2 light-emitting elements or the on of both represents different indication information.

[0004] It is necessary to design a suitable switch control circuit to independently control the on and off of each light-emitting element in the same aid navigation lamp fixture. Summary of the Invention

[0005] The present invention provides a switch control circuit, a single lamp monitoring device, a lamp and a system.

[0006] The present invention adopts the following technical solution: A switch control circuit includes: two transistors with the same polarity, a voltage limiting circuit, a unidirectional conduction circuit, a capacitor and an input circuit;

[0007] The gates of the two transistors are short-circuited and connected, the sources are short-circuited and connected and connected to the first end of the capacitor, and the drains are respectively used to connect to the 2 ends of the controlled light-emitting element;

[0008] The input circuit is used to receive a control signal and short-circuit or disconnect the connection between the first end of the capacitor and the gates of the two transistors according to the control signal;

[0009] The voltage limiting circuit is used to limit the amplitude of the effective gate-source voltage (i.e., the gate-source voltage that can make the transistor conduct) of the two transistors;

[0010] The unidirectional conduction circuit is connected to the fixed voltage terminal, the second terminal of the capacitor, and the gates of the two transistors, allowing current to flow unidirectionally from the fixed voltage terminal to the second terminal of the capacitor and allowing current to flow unidirectionally from the second terminal of the capacitor to the gates of the two transistors, or allowing current to flow unidirectionally from the second terminal of the capacitor to the fixed voltage terminal and allowing current to flow unidirectionally from the gates of the two transistors to the second terminal of the capacitor, wherein the current flowing unidirectionally between the gates of the two transistors and the second terminal of the capacitor is used to make the gate voltage of the two transistors an effective voltage.

[0011] Optionally, the voltage limiting circuit includes a transient voltage suppression diode; when the two transistors are NMOS transistors, the cathode of the transient voltage suppression diode is connected to the gates of the two transistors, and the anode is connected to the sources of the two transistors; when the two transistors are PMOS transistors, the cathode of the transient voltage suppression diode is connected to the sources of the two transistors, and the anode is connected to the gates of the two transistors.

[0012] Optionally, the unidirectional conduction circuit includes a first diode connected between the fixed voltage terminal and the second terminal of the capacitor and a second diode connected between the second terminal of the capacitor and the gates of the two transistors; when the two transistors are NMOS transistors, the first diode allows current to flow unidirectionally from the fixed voltage terminal to the second terminal of the capacitor; when the two transistors are PMOS transistors, the first diode allows current to flow unidirectionally from the second terminal of the capacitor to the fixed voltage terminal.

[0013] Optionally, the input circuit includes an optocoupler, and the two output terminals of the optocoupler are respectively connected to the gates of the two transistors and the first terminal of the capacitor.

[0014] The present invention adopts the following technical solution: a single lamp monitoring device includes at least one of the aforementioned switch control circuits.

[0015] The present invention adopts the following technical solution: a lamp includes a plurality of light-emitting elements connected in series and the aforementioned single lamp monitoring device.

[0016] The present invention adopts the following technical solution: an aid navigation lamp monitoring system includes the aforementioned single lamp monitoring device or the aforementioned lamp, and includes a constant current dimmer.

[0017] The switch control circuit of the present invention can quickly respond to control signals, enabling the light-emitting elements connected in series to be independently controlled to be lit or extinguished, and ensuring safe and controllable operation during the working process. Description of the Drawings

[0018] Figure 1 is the circuit diagram of the aid navigation lamp monitoring system.

[0019] Figure 2It is a partial circuit diagram of an aid-to-navigation light monitoring system, which shows the internal circuit diagram of a single-light monitoring device.

[0020] Figures 3 to 6 is Figure 2 The equivalent circuit diagram of different working states of the shown circuit.

[0021] Figure 7 is Figure 2 A variant form of the shown partial circuit diagram. Detailed implementation manners

[0022] The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

[0023] Combined with Figures 1 to 6 , the following introduces the switch control circuit and its working principle of an embodiment of the present invention.

[0024] Referring to Figure 1 , three single-light monitoring devices are respectively connected in series with a constant current dimmer through isolation transformers TR1, TR2, and TR3. Figure 1 exemplarily shows a partial circuit diagram inside one of the single-light monitoring devices. The primary side of the internal transformer TR4, the secondary side of the isolation transformer TR1, the light-emitting element LAMP-A, and the light-emitting element LAMP-B are connected in series to form a loop. The secondary side of the isolation transformer TR1 can be approximately equivalent to a constant current source. The secondary side of the internal transformer TR4 supplies power to the power supply module, and the power supply module generates a DC voltage to provide a DC power supply voltage for the switch control circuit ( Figure 1 not shown in). The power supply terminals VCC and VDD of the power supply module respectively provide different DC power supply voltages. In this embodiment, the DC voltage provided by the power supply terminal VDD is higher than the DC voltage provided by the power supply terminal VCC. The light-emitting elements connected in series with the secondary side of the isolation transformer TR1 can also be three or more. The number of single-light monitoring devices can also be up to hundreds.

[0025] Since the light-emitting elements LAMP-A and LAMP-B are in series, to turn off one of the light-emitting elements, it is necessary to short-circuit its two ends. In the prior art, a relay is mostly used as a switching element, and in this embodiment, an NMOS transistor is used as a switching element to improve the response speed.

[0026] The gates of the transistors Q3 and Q4 are connected to the fourth node U4. The sources of the transistors Q3 and Q4 are connected to the second node U2 and the negative electrode of the capacitor C2. The drains of the transistors Q3 and Q4 are respectively connected to both ends of the light-emitting element LAMP-A.

[0027] When the voltage difference between the fourth node U4 and the second node U2 is greater than the threshold voltages of the transistors Q3 and Q4, the transistors Q3 and Q4 turn on, and the light-emitting element LAMP-A is short-circuited, and the light-emitting element LAMP-A goes out.

[0028] The cathode of the transient voltage suppression diode DZ3 is connected to the gate of the transistor Q3, and the anode is connected to the second node U2. The cathode of the transient voltage suppression diode DZ4 is connected to the gate of the transistor Q4, and the anode is connected to the second node U2. The function of the transient voltage suppression diodes DZ3 and DZ4 is to prevent the gate-source voltage difference of the transistors Q3 and Q4 from being too large, thereby protecting the transistors Q3 and Q4.

[0029] The anode of the light-emitting diode in the optocoupler OC2 is connected to the power supply terminal VCC, and the cathode is connected to the control terminal MCU_PA2. The single-lamp monitoring device receives control signals from other devices, for example, through power line carrier communication, and then sets the voltage state of the control terminal MCU_PA2 according to the control signals. The circuits related to communication and signal processing in the single-lamp monitoring device are not shown, and this part can be designed according to the existing technology.

[0030] When the control terminal MCU_PA2 receives a high-level control signal, the light-emitting diode inside the optocoupler OC2 turns off, and the triode inside the optocoupler OC2 turns off. The connection between the second node U2 and the fourth node U4 is disconnected. At this time, refer to the equivalent circuit Figure 3 .

[0031] The resistor R4 and the diode D3 are connected in series between the fourth node U4 and the fifth node U5, allowing current to flow unidirectionally from the fifth node U5 to the fourth node U4.

[0032] The resistor R5 and the diode D4 are connected in series between the power supply terminal VDD and the fifth node U5, allowing current to flow unidirectionally from the power supply terminal VDD to the fifth node U5.

[0033] The positive electrode of the capacitor C2 is connected to the fifth node, and the negative electrode is connected to the second node.

[0034] In the current state, the negative electrode of the capacitor C2 is connected to the first node U1 (i.e., grounded) through the second node U2 and the parasitic diode of the transistor Q4 in sequence. The power supply terminal VDD charges the anode of the capacitor C2 through the diode D4 and the resistor R5. After reaching the steady state, the voltage difference between the anode and the cathode of the capacitor C2 is approximately the voltage of the power supply terminal VDD.

[0035] The power supply terminal VDD further charges the fourth node (i.e., the gates of transistors Q3 and Q4) through diode D4, resistor R5, resistor R4, and diode D3. The voltage difference between the fourth node U4 and the second node U2 is large enough, that is, the gate-source voltage difference of transistors Q3 and Q4 is large enough, and transistors Q3 and Q4 are turned on. The light-emitting element LAMP-A is turned off due to being short-circuited.

[0036] When the control terminal MCU_PA2 receives a low-level control signal, the light-emitting diode inside the optocoupler OC2 is turned on, and the triode inside the optocoupler OC2 is turned on. There is an approximate short-circuit connection between the second node U2 and the fourth node U4. At this time, the equivalent circuit reference Figure 4 。

[0037] The gate-source electrodes of transistors Q3 and Q4 are short-circuited, transistors Q3 and Q4 are turned off, and the light-emitting element LAMP-A is lit. The positive electrode of capacitor C2 discharges to its negative electrode through resistor R4 and diode D3, and the voltage difference across capacitor C2 is approximately 0V.

[0038] In this embodiment, the structure of the switching control circuit of the light-emitting element LAMP-B is the same as that of the switching control circuit of the light-emitting element LAMP-A.

[0039] Continue to analyze the working process of the switching control circuit of the light-emitting element LAMP-B.

[0040] When the light-emitting element LAMP-A is short-circuited, the drain of transistor Q2 in the switching control circuit of the light-emitting element LAMP-B is grounded, and the working process of the switching control circuit of the light-emitting element LAMP-B is the same as the foregoing analysis.

[0041] When the light-emitting element LAMP-A is lit, it is approximately a resistor, and the voltage of the third node U3 fluctuates between a relatively large positive voltage and a negative voltage. For example, assume that the power of the light-emitting element LAMP-A is 100W, the effective value of the alternating current is 6.6A, and the effective value of the voltage difference between the third node U3 and the first node U1 (i.e., ground) is 15V. The voltage of the third node U3 fluctuates between approximately -21V and 21V.

[0042] When the control terminal MCU_PA1 receives a high-level voltage, the light-emitting diode inside the optocoupler OC1 is turned off, causing the internal triode to be turned off, and the eighth node U8 is disconnected from the sixth node U6. The equivalent circuit reference Figure 5 。

[0043] When the voltage of the third node U3 is lower than the voltage of the power supply terminal VDD, the power supply terminal VDD charges the capacitor C1 through the diode D2 and the resistor R2, and charges the eighth node through the diode D2, the resistor R2, the resistor R1, and the diode D1. When the voltage of the third node U3 is greater than the voltage of the power supply terminal VDD, the circuit between the third node U3 and the negative electrode of the capacitor C1 is disconnected, and the voltage difference across the capacitor C1 remains unchanged at this time. This causes the voltage across the capacitor C1 to continue to rise, that is, the voltage difference between the eighth node and the sixth node (i.e., the gate-source voltage difference of the transistors Q1 and Q2) will continue to rise. Limited by the clamping effect of the transient voltage suppression diodes DZ1 and DZ2, the voltage across the capacitor C1 will not be greater than the clamping voltages of the transient voltage suppression diodes DZ1 and DZ2. At this time, the transistors Q1 and Q2 are turned on, and the light-emitting element LAMP-B goes out.

[0044] When the control terminal MCU_PA1 receives a low-level voltage, the internal light-emitting diode of the optocoupler OC1 conducts, causing the internal triode to conduct, and the eighth node U8 and the sixth node U6 are approximately short-circuited, that is, the gate-source electrodes of the transistors Q1 and Q2 are approximately short-circuited. Refer to Figure 6 .

[0045] The transistors Q1 and Q2 are turned off, and the light-emitting element LAMP-B lights up.

[0046] The above switch control circuit uses transistors as the core devices to control whether the light-emitting element is short-circuited, with a fast response speed, and the working state of the switch control circuit is safe and stable.

[0047] In Figure 2 In a variation of the shown circuit diagram, the switch control circuit of the light-emitting element LAMP-A omits the transient voltage suppression diodes DZ3 and DZ4. This is because one end of the light-emitting element LAMP-A is grounded, and the voltage at this point is stable.

[0048] In Figure 2 In another variation of the shown circuit diagram, 3 or more light-emitting elements are connected in series. Except for the light-emitting element with one end grounded, the switch control circuits of the remaining light-emitting elements should be designed in the manner shown in the figure.

[0049] In Figure 2 In another variation of the shown circuit diagram, the number of transient voltage suppression diodes in the switch control circuit corresponding to a single light-emitting element is 1.

[0050] In Figure 2 In another variation of the shown circuit diagram, the device for limiting the upper limit of the gate-source voltage difference of the transistor is not limited to the transient voltage suppression diode, and any other known circuit structure with voltage limiting can be used for this purpose.

[0051] InFigure 2 In another variation of the shown circuit diagram, with reference to Figure 7 , two NMOS transistors are replaced by two PMOS transistors, and the working principle can refer to the foregoing embodiments. The polarity of the power supply is adjusted, and the orientation of the diode is adjusted. For example, the cathode of diode D2 is grounded, and the first node U1 is connected to the power supply terminal VDD.

[0052] In Figure 2 another variation of the shown circuit diagram, the input circuit composed of the optocoupler OC1 and the resistor R3 can also be replaced by a single IGBT tube, or any other known circuit form that controls the on-off relationship between two points and can withstand a large voltage.

[0053] Combining the above embodiments, the switch control circuit of the present invention includes: two transistors with the same polarity (such as Figure 2 the transistors Q3 and Q4 in Figure 2 ), a voltage limiting circuit (such as including Figure 2 the transient voltage suppression diodes DZ3 and DZ4 in Figure 2 ), a unidirectional conduction circuit (such as including

[0054] the diodes D3 and D4 and the resistors R4 and R5 in

[0055] ), a capacitor and an input circuit (such as including

[0056] the optocoupler OC2 and the resistor R6 in

[0057] ); the gates of the two transistors are short-circuited, the sources are short-circuited and connected to the first end of the capacitor, and the drains are respectively used to connect the two ends of the controlled light-emitting element;

[0058] The input circuit is used to receive a control signal and short-circuit or disconnect the connection between the first end of the capacitor and the gates of the two transistors according to the control signal; Figures 1 to 7 The voltage limiting circuit is used to limit the amplitude of the effective gate-source voltage of the two transistors;

[0059] The unidirectional conduction circuit is connected to the fixed voltage terminal, the second end of the capacitor and the gates of the two transistors, and allows current to flow unidirectionally from the fixed voltage terminal to the second end of the capacitor and allows current to flow unidirectionally from the second end of the capacitor to the gates of the two transistors, or allows current to flow unidirectionally from the second end of the capacitor to the fixed voltage terminal and allows current to flow unidirectionally from the gates of the two transistors to the second end of the capacitor. Among them, the current flowing unidirectionally between the gates of the two transistors and the second end of the capacitor is used to make the gate voltage of the two transistors an effective voltage.

[0058] Based on the same inventive concept, with reference to Figures 1 to 7 , an embodiment of the present invention further provides a single-lamp monitoring device, including at least one of the above switch control circuits.

[0059] Based on the same inventive concept, an embodiment of the present invention further provides a lighting fixture, including the above single-lamp monitoring device and at least two light-emitting elements.

[0060] That is, the single-lamp monitoring device can be independent of the light-emitting elements or integrated with the light-emitting elements.

[0061] The lighting fixture can specifically be an aid navigation light.

[0062] It should be noted that since one of the light-emitting elements at the end position in the series-connected light-emitting elements has one end that is not connected to other light-emitting elements and is connected to a fixed voltage, for example Figure 3 in which the first node U1 is grounded, for example Figure 7 in which the first node U1 is connected to the power supply terminal VDD, the switching control circuit corresponding to this light-emitting element LAMP-A can be designed in other circuit forms, and the present invention does not limit this.

[0063] Based on the same inventive concept, an embodiment of the present invention further provides an aid navigation light monitoring system, including the aforementioned single-lamp monitoring device or the aforementioned lighting fixture, and including a constant current dimmer.

[0064] The overall structure of the aid navigation light monitoring system refers to Figure 1 . The aid navigation light monitoring system also includes, for example, a host computer (not shown), which is also connected in series in the series circuit where the constant current dimmer is located through an isolation transformer. Communication between the host computer and the single-lamp monitoring device is, for example, carried out by power line carrier or wireless connection.

[0065] The protection scope of the present invention is not limited to the above embodiments. Obviously, those skilled in the art can make various changes and deformations to the present invention without departing from the scope and spirit of the present invention. If these changes and deformations fall within the scope of the claims of the present invention and their equivalent technologies, the intention of the present invention also includes these changes and deformations.

Claims

1. A single-lamp monitoring device, characterized in that, Comprising at least two switch control circuits; The switch control circuit includes: two transistors with the same polarity, a voltage limiting circuit, a unidirectional conduction circuit, a capacitor, and an input circuit; The gates of the two transistors are short-circuited and connected, the sources are short-circuited and connected to the first end of the capacitor, and the drains are respectively used to connect to the two ends of the controlled light-emitting element; The input circuit is used to receive a control signal and short-circuit or disconnect the connection between the first end of the capacitor and the gates of the two transistors according to the control signal; The voltage limiting circuit is used to limit the amplitude of the effective gate-source voltage of the two transistors; The unidirectional conduction circuit is connected to the fixed voltage terminal, the second end of the capacitor, and the gates of the two transistors. When the two transistors are NMOS transistors, it allows current to flow unidirectionally from the fixed voltage terminal to the second end of the capacitor and allows current to flow unidirectionally from the second end of the capacitor to the gates of the two transistors. Or when the two transistors are PMOS transistors, it allows current to flow unidirectionally from the second end of the capacitor to the fixed voltage terminal and allows current to flow unidirectionally from the gates of the two transistors to the second end of the capacitor. Among them, the current flowing unidirectionally between the gates of the two transistors and the second end of the capacitor is used to make the gate voltage of the two transistors an effective voltage; The two transistors with the same polarity in all the switch control circuits are connected in series. The two ends of the series part where the two transistors with the same polarity in all the switch control circuits are located are used to connect to the secondary side of the isolation transformer. The drain of one transistor at the end position among the two transistors with the same polarity in all the switch control circuits is grounded.

2. The single-lamp monitoring device according to claim 1, characterized in that, The voltage limiting circuit includes a transient voltage suppression diode; when the two transistors are NMOS transistors, the cathode of the transient voltage suppression diode is connected to the gates of the two transistors, and the anode is connected to the sources of the two transistors; when the two transistors are PMOS transistors, the cathode of the transient voltage suppression diode is connected to the sources of the two transistors, and the anode is connected to the gates of the two transistors.

3. The single-lamp monitoring device according to claim 1, characterized in that, The unidirectional conduction circuit includes a first diode connected between the fixed voltage terminal and the second end of the capacitor and a second diode connected between the second end of the capacitor and the gates of the two transistors; when the two transistors are NMOS transistors, the first diode allows current to flow unidirectionally from the fixed voltage terminal to the second end of the capacitor; when the two transistors are PMOS transistors, the first diode allows current to flow unidirectionally from the second end of the capacitor to the fixed voltage terminal.

4. The single-lamp monitoring device according to claim 1, characterized in that The input circuit includes an optocoupler, and the two output terminals of the optocoupler are respectively connected to the gates of the two transistors and the first end of the capacitor.

5. A lighting fixture, characterized in that, Comprising a plurality of light-emitting elements connected in series and the single-lamp monitoring device according to any one of claims 1 to 4.

6. A navigation light monitoring system, characterized in that, Comprising the single-lamp monitoring device according to any one of claims 1 to 4 or the lighting fixture according to claim 5, and including a constant current dimmer.

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