A luminaire fault detection circuit

Abstract

The application provides a lamp fault detection circuit, comprising: a first signal detection module, a first input end of which is connected with an output end of a transformer, a second input end of which is connected with a source electrode of a switch tube, and an output end of which is connected with a first input end of a control module, for detecting a first pulse signal; a second signal detection module, an input end of which is connected with the source electrode of the switch tube, and an output end of which is connected with a second input end of the control module, for detecting a second pulse signal when a short circuit occurs in the circuit; a third signal detection module, for detecting a third pulse signal; a fourth signal detection module, for detecting a fourth pulse signal; a lamp module, an input end of which is connected with the second signal detection module, and an output end of which is connected with a drain electrode of the switch tube; and the control module is further connected with a state display module, for controlling the state display module to display corresponding states according to the first pulse signal, the second pulse signal, the third pulse signal and the fourth pulse signal. The application has the beneficial effect that the state of the lamp module can be fully covered and detected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lamp fault detection, and particularly relates to a lamp fault detection circuit. BACKGROUND

[0002] The lamp fault detection circuit is relatively common in the related application circuit of the lamp, and is mainly used for detecting the open circuit fault and the short circuit fault of the lamp in the circuit. However, the current lamp fault detection circuit usually only detects the non-dimming lamp. Since the whole lamp power of the dimming lamp is particularly small under deep dimming, the detection is relatively difficult, so that the current lamp fault detection circuit does not involve the fault detection of the dimming lamp. SUMMARY

[0003] In view of the problems in the prior art, the present application provides a lamp fault detection circuit, which comprises:

[0004] a first signal detection module, a first input end of the first signal detection module is connected with an output end of a transformer, a second input end of the first signal detection module is connected with a source electrode of a switching tube, and an output end of the first signal detection module is connected with a first input end of a control module, for detecting a first pulse signal and outputting;

[0005] a second signal detection module, an input end of the second signal detection module is connected with the source electrode of the switching tube, and an output end of the second signal detection module is connected with a second input end of the control module, for detecting a second pulse signal and outputting when a short circuit occurs in the circuit;

[0006] a third signal detection module, an input end of the third signal detection module is connected with the source electrode of the switching tube, and an output end of the third signal detection module is connected with a third input end of the control module, for detecting a third pulse signal and outputting;

[0007] a fourth signal detection module, an input end of the fourth signal detection module is connected with the source electrode of the switching tube, and an output end of the fourth signal detection module is connected with a fourth input end of the control module, for detecting a fourth pulse signal and outputting;

[0008] a lamp module, an input end of the lamp module is connected with the second signal detection module, and an output end of the lamp module is connected with a drain electrode of the switching tube;

[0009] The control module is further connected with a state display module, and the control module is used for controlling the state display module to display the corresponding state according to the first pulse signal, the second pulse signal, the third pulse signal and the fourth pulse signal.

[0010] Preferably, the first signal detection module comprises:

[0011] a first rectifier tube, a drain of the first rectifier tube being connected to a first output end of the transformer;

[0012] a second rectifier tube, a source of the second rectifier tube being connected to a source of the first rectifier tube, a drain of the second rectifier tube being connected to a second output end of the transformer;

[0013] a first transient suppression diode, a positive pole of the first transient suppression diode being connected to a source of the switch tube, a negative pole of the first transient suppression diode being connected to the control module;

[0014] a first resistor, one end of the first resistor being connected to the negative pole of the first transient suppression diode, the other end of the first resistor being connected to the positive pole of the first transient suppression diode;

[0015] a second resistor, one end of the second resistor being connected to one end of the first resistor, the other end of the second resistor being connected to an external first power supply;

[0016] a first capacitor, one end of the first capacitor being connected to one end of the first resistor, the other end of the first capacitor being connected to the drain of the second rectifier tube;

[0017] the drain of the first rectifier tube being used as a first input end of the first signal detection module, the positive pole of the first transient suppression diode being used as a second input end of the first signal detection module, the negative pole of the first transient suppression diode being used as an output end of the first signal detection module;

[0018] the first capacitor being coupled and inductively detected to obtain the first pulse signal and convert the first pulse signal into a forward pulse signal through the first transient suppression diode and output to the control module.

[0019] Preferably, the first rectifier tube and the second rectifier tube are P-channel field effect tubes.

[0020] Preferably, the first power supply is a 3.3-volt power supply.

[0021] Preferably, the second signal detection module comprises:

[0022] a second transient suppression diode, a positive pole of the second transient suppression diode being connected to a source of the switch tube, a negative pole of the second transient suppression diode being connected to the control module;

[0023] a third resistor, one end of the third resistor being connected to the negative pole of the second transient suppression diode, the other end of the third resistor being connected to the positive pole of the second transient suppression diode;

[0024] a fourth resistor, one end of the fourth resistor is connected to one end of the third resistor, and the other end of the fourth resistor is connected to the input end of the lamp module;

[0025] a second capacitor, one end of the second capacitor is connected to one end of the fourth resistor, and the other end of the second capacitor is connected to the other end of the fourth resistor;

[0026] a first amplifier, a first input pin of the first amplifier is connected to the second external power supply, a second input pin of the first amplifier is connected to one end of the second capacitor, and an output pin of the first amplifier is connected to the control module;

[0027] the positive electrode of the second transient suppression diode is used as the input end of the second signal detection module, and the output pin of the first amplifier is used as the output end of the second signal detection module;

[0028] the second capacitor is used for coupling and inductive detection to obtain the second pulse signal and output the second pulse signal to the first amplifier for amplification, and the first amplifier is used for outputting the amplified second pulse signal to the control module.

[0029] Preferably, the third signal detection module comprises:

[0030] a third transient suppression diode, the positive electrode of the third transient suppression diode is connected to the source electrode of the switch tube, and the negative electrode of the third transient suppression diode is connected to the control module;

[0031] a fifth resistor, one end of the fifth resistor is connected to the negative electrode of the third transient suppression diode, and the other end of the fifth resistor is connected to the positive electrode of the third transient suppression diode;

[0032] a third capacitor, one end of the third capacitor is connected to one end of the fifth resistor, and the other end of the third capacitor is connected to the drain electrode of the switch tube;

[0033] a second amplifier, a first input pin of the second amplifier is connected to the negative electrode of the third transient suppression diode, a second input pin of the second amplifier is connected to the second external power supply, and an output pin of the second amplifier is connected to the control module;

[0034] the positive electrode of the third transient suppression diode is used as the input end of the third signal detection module, and the output pin of the second amplifier is used as the output end of the third signal detection module;

[0035] the third capacitor is used for coupling and inductive detection to obtain the third pulse signal and output the third pulse signal to the second amplifier for amplification, and the second amplifier is used for outputting the amplified third pulse signal to the control module.

[0036] Preferably, the fourth signal detection module comprises:

[0037] a third amplifier, a first input pin of the third amplifier is connected to the source of the switch tube, and an output pin of the third amplifier is connected to the control module;

[0038] a sixth resistor, one end of the sixth resistor is connected to a second input pin of the third amplifier, and the other end of the sixth resistor is connected to an external second power supply;

[0039] a seventh resistor, one end of the seventh resistor is connected to one end of the sixth resistor;

[0040] an eighth resistor, one end of the eighth resistor is connected to the other end of the seventh resistor, and the other end of the eighth resistor is connected to the source of the switch tube;

[0041] the first input pin of the third amplifier serves as an input end of the fourth signal detection module, and the output pin of the third amplifier serves as an output end of the fourth signal detection module;

[0042] the fourth pulse signal output by the switch tube is amplified by the third amplifier, and the amplified fourth pulse signal is output to the control module.

[0043] Preferably, the switch tube is a P-channel field effect tube.

[0044] Preferably, the lamp module comprises:

[0045] a ninth resistor, one end of the ninth resistor is connected to the second signal detection module;

[0046] a light-emitting diode, a positive electrode of the light-emitting diode is connected to the other end of the ninth resistor, and a negative electrode of the light-emitting diode is connected to the drain of the switch tube;

[0047] one end of the ninth resistor serves as an input end of the lamp module, and the negative electrode of the light-emitting diode serves as an output end of the lamp module.

[0048] Preferably, the control module comprises:

[0049] a first control unit, configured to control the state display module to prompt that the lamp module is in an open circuit state when the first pulse signal is at a low value and the second pulse signal is not received, and control the state display module to prompt that the lamp module is in a conduction state when the first pulse signal is at a high value;

[0050] a second control unit, configured to control the switch tube to be turned off and control the state display module to prompt that the lamp module is in a short circuit state when the second pulse signal is received;

[0051] a third control unit, configured to control the state display module to prompt that the lamp module is in a dimming state when the third pulse signal is received;

[0052] a fourth control unit, configured to control the switch tube to be turned off and control the state display module to prompt that the lamp module is in an over-power state when the fourth pulse signal is received.

[0053] The above technical solution has the following advantages or beneficial effects:

[0054] 1) The lamp fault detection circuit in the present application is provided with four signal detection modules to detect four pulse signals of the lamp module respectively, and the pulse signals are amplified by an amplifier to solve the problem of too small signal;

[0055] 2) The lamp fault detection circuit in the present application can analyze and judge that the lamp module is in an open circuit state or a conduction state or a short circuit state or a dimming state or an over-power state according to the four pulse signals, and the state of the lamp module is prompted in real time by the state display module;

[0056] 3) The lamp fault detection circuit in the present application can cut off the switch tube protection circuit in time when the lamp module is in a short circuit state or an over-power state, so as to avoid damage to the circuit;

[0057] 4) The lamp fault detection circuit in the present application analyzes and judges by the first pulse signal when the lamp module is a non-dimming lamp, and analyzes and judges by the third pulse signal when the lamp module is a dimming lamp, so as to realize full coverage detection of non-dimming lamps and dimming lamps. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 In the preferred embodiment of the present application, the electrical schematic diagram of the circuit;

[0059] Figure 2 In the preferred embodiment of the present application, the connection diagram of the control module. DETAILED DESCRIPTION

[0060] The present application will be described in detail below in combination with the drawings and specific embodiments. The present application is not limited to this embodiment, and other embodiments can also belong to the scope of the present application as long as they meet the main idea of the present application.

[0061] In the preferred embodiment of the present application, based on the above problems existing in the prior art, a lamp fault detection circuit is provided, which comprises:

[0062] a first signal detection module 1, a first input end of the first signal detection module 1 is connected to an output end of a transformer, a second input end of the first signal detection module 1 is connected to a source electrode of a switch tube Q1, an output end of the first signal detection module 1 is connected to a first input end a1 of a control module 2, for detecting a first pulse signal and outputting;

[0063] a second signal detection module 3, an input end of the second signal detection module 3 is connected to the source electrode of the switch tube Q1, an output end of the second signal detection module 3 is connected to a second input end a2 of the control module 2, for detecting a second pulse signal when a short circuit occurs in the circuit and outputting;

[0064] a third signal detection module 4, an input end of the third signal detection module 4 is connected to the source electrode of the switch tube Q1, an output end of the third signal detection module 4 is connected to a third input end a3 of the control module 2, for detecting a third pulse signal and outputting;

[0065] a fourth signal detection module 5, an input end of the fourth signal detection module 5 is connected to the source electrode of the switch tube Q1, an output end of the fourth signal detection module 5 is connected to a fourth input end a4 of the control module 2, for detecting a fourth pulse signal and outputting;

[0066] a lamp module 6, an input end of the lamp module 6 is connected to the second signal detection module 3, an output end of the lamp module 6 is connected to a drain electrode of the switch tube Q1;

[0067] The control module 2 is further connected to a state display module 7, and the control module 2 is used for controlling the state display module 7 to display a corresponding state according to the first pulse signal, the second pulse signal, the third pulse signal and the fourth pulse signal.

[0068] Specifically, in the embodiment, considering that current lamps are roughly divided into non-dimming lamps and dimming lamps, when the lamp module 6 is a non-dimming lamp, the control module 2 analyzes and judges according to the number of pulses of the first pulse signal, and when the lamp module 6 is a dimming lamp, the control module 2 analyzes and judges according to the waveform of the third pulse signal, thereby realizing full-coverage detection of non-dimming lamps and dimming lamps.

[0069] Preferably, the third signal detection module 4 can detect the third pulse signal of the dimming lamp at different depth dimming and analyze the corresponding state according to the waveform of the third pulse signal and control the on-off of the switch tube Q1 for timely protection.

[0070] Specifically, in the embodiment, considering that the lamp module 6 has a greater impact on the circuit when short-circuited, if protection is not performed in time, the circuit will be damaged, therefore, a switch tube Q1 is arranged to connect the lamp module 6 and control the switch tube Q1 to be disconnected by the control module 2 when the lamp module 6 is short-circuited to protect the circuit.

[0071] Preferably, the control module 2 judges whether the lamp module 6 is short-circuited by whether the second pulse signal is received, and when the second pulse signal is received, the control module 2 determines that the lamp module 6 is short-circuited and controls the switch tube Q1 to be turned off to protect the circuit.

[0072] Preferably, the second pulse signal is a falling pulse signal.

[0073] Specifically, in the embodiment, when the lamp module 6 is disconnected, i.e. the lamp module 6 is turned off, the circuit is in a low-power consumption mode, the first signal detection module 1 detects very few pulses of the first pulse signal, and thus the control module 2 determines that the lamp module 6 is in an open circuit state and prompts through the state display module 7 when the number of pulses of the first pulse signal is low and the second pulse signal is not received.

[0074] Specifically, in the embodiment, when the power of the lamp module 6 exceeds a safety value, the fourth signal detection module 5 can detect the fourth pulse signal, at which time the control module 2 controls the switch tube Q1 to be turned off to protect the circuit and prompts through the state display module 7.

[0075] In a preferred embodiment of the present application, the first signal detection module 1 comprises:

[0076] a first rectifier tube Q2, the drain of the first rectifier tube Q2 being connected to the first output end of the transformer TR1;

[0077] a second rectifier tube Q3, the source of the second rectifier tube Q3 being connected to the source of the first rectifier tube Q2, and the drain of the second rectifier tube Q3 being connected to the second output end of the transformer TR1;

[0078] a first transient suppression diode ZD1, the anode of the first transient suppression diode ZD1 being connected to the source of the switch tube Q1, and the cathode of the first transient suppression diode ZD1 being connected to the control module 2;

[0079] a first resistor R1, one end of the first resistor R1 being connected to the cathode of the first transient suppression diode ZD1, and the other end of the first resistor R1 being connected to the anode of the first transient suppression diode ZD1;

[0080] a second resistor R2, one end of the second resistor R2 being connected to one end of the first resistor R1, and the other end of the second resistor R2 being connected to the first external power supply;

[0081] a first capacitor C1, one end of the first capacitor C1 being connected to one end of the first resistor R1, and the other end of the first capacitor C1 being connected to the drain of the second rectifier tube Q3;

[0082] The drain of the first rectifier tube Q2 is used as the first input end of the first signal detection module 1, the positive pole of the first transient suppression diode Q2 is used as the second input end of the first signal detection module 1, and the negative pole of the first transient suppression diode Q2 is used as the output end of the first signal detection module 1.

[0083] The first capacitor C1 is coupled to inductively detect a first pulse signal and convert the first pulse signal into a forward pulse signal through the first transient suppression diode ZD1 and output the forward pulse signal to the control module 2.

[0084] Specifically, in the embodiment, considering that the output of the transformer TR1 is a negative waveform, the first pulse signal obtained by the first capacitor C1 is also a negative pulse signal, and the control module 2 cannot detect the negative pulse signal, therefore, a first transient suppression diode ZD1 is connected to one end of the first capacitor C1, the first pulse signal is converted into a forward pulse signal through the first transient suppression diode ZD1, so that the control module 2 can detect and obtain the first pulse signal.

[0085] In the preferred embodiment of the present application, the first rectifier tube Q2 and the second rectifier tube Q3 are P-channel field effect tubes.

[0086] In the preferred embodiment of the present application, the first power supply is a 3.3-volt power supply.

[0087] In the preferred embodiment of the present application, the second signal detection module 3 comprises:

[0088] A second transient suppression diode ZD2, the positive pole of the second transient suppression diode ZD2 is connected to the source of the switch tube Q1, and the negative pole of the second transient suppression diode ZD2 is connected to the control module 2.

[0089] A third resistor R3, one end of the third resistor R3 is connected to the negative pole of the second transient suppression diode ZD2, and the other end of the third resistor R3 is connected to the positive pole of the second transient suppression diode ZD2.

[0090] A fourth resistor R4, one end of the fourth resistor R4 is connected to one end of the third resistor R3, and the other end of the fourth resistor R4 is connected to the input end of the lamp module 6.

[0091] A second capacitor C2, one end of the second capacitor C2 is connected to one end of the fourth resistor R4, and the other end of the second capacitor C2 is connected to the other end of the fourth resistor R4.

[0092] A first amplifier U1A, the first input pin of the first amplifier U1A is connected to an external second power supply Vref, the second input pin of the first amplifier U1A is connected to one end of the second capacitor C2, and the output pin of the first amplifier U1A is connected to the control module 2.

[0093] The positive pole of the second transient suppression diode ZD2 is used as the input end of the second signal detection module 3, and the output pin of the first amplifier U1A is used as the output end of the second signal detection module 3;

[0094] The second capacitor C2 is coupled to inductively detect the second pulse signal and output to the first amplifier U1A for amplification, and the amplified second pulse signal is output to the control module 2 through the first amplifier U1A.

[0095] Specifically, in the embodiment, considering that the output of the transformer TR1 is a negative waveform, the second pulse signal obtained by the coupling induction of the first capacitor C2 is also a negative pulse signal, and the control module 2 cannot detect the negative pulse signal, therefore, a second transient suppression diode ZD2 is connected to one end of the second capacitor C2, and the second transient suppression diode ZD2 is used to convert the second pulse signal into a positive pulse signal so that the control module 2 can detect and obtain the second pulse signal.

[0096] Preferably, considering that the second pulse signal may be too low, the first amplifier U1A is arranged to amplify the second pulse signal.

[0097] In the preferred embodiment of the present application, the third signal detection module 4 comprises:

[0098] A third transient suppression diode ZD3, the positive pole of the third transient suppression diode ZD3 is connected to the source of the switch tube Q1, and the negative pole of the third transient suppression diode ZD3 is connected to the control module 2;

[0099] A fifth resistor R5, one end of the fifth resistor R5 is connected to the negative pole of the third transient suppression diode ZD3, and the other end of the fifth resistor R5 is connected to the positive pole of the third transient suppression diode ZD3;

[0100] A third capacitor C3, one end of the third capacitor C3 is connected to one end of the fifth resistor R5, and the other end of the third capacitor C3 is connected to the drain of the switch tube Q1;

[0101] A second amplifier U2A, the first input pin of the second amplifier U2A is connected to the negative pole of the third transient suppression diode ZD3, the second input pin of the second amplifier U2A is connected to the external second power supply Vref, and the output pin of the second amplifier U2A is connected to the control module 2;

[0102] The positive pole of the third transient suppression diode ZD3 is used as the input end of the third signal detection module 4, and the output pin of the second amplifier U2A is used as the output end of the third signal detection module 4;

[0103] The third capacitor C3 is coupled to inductively detect a third pulse signal and output to the second amplifier U2A for amplification, and the amplified third pulse signal is output to the control module 2 through the second amplifier U2A.

[0104] Specifically, in the embodiment, considering that the output of the transformer TR1 is a negative waveform, the third pulse signal inductively coupled by the third capacitor C3 is also a negative pulse signal, and the control module 2 cannot detect the negative pulse signal, therefore, a third transient suppression diode ZD3 is connected to one end of the third capacitor C3, and the third pulse signal is converted into a positive pulse signal by the third transient suppression diode ZD3 so that the control module 2 can detect and obtain the third pulse signal.

[0105] Preferably, the corresponding pulse signal can be detected by the way of coupling inductance through different capacitors.

[0106] Preferably, considering that the third pulse signal may be too low, the second amplifier U2A is arranged to amplify the third pulse signal.

[0107] In a preferred embodiment of the present application, the fourth signal detection module 5 comprises:

[0108] a third amplifier U3A, a first input pin of the third amplifier U3A is connected to the source of the switch tube Q1, and an output pin of the third amplifier U3A is connected to the control module 2;

[0109] a sixth resistor R6, one end of the sixth resistor R6 is connected to a second input pin of the third amplifier U3A, and the other end of the sixth resistor R6 is connected to an external second power supply Vref;

[0110] a seventh resistor R7, one end of the seventh resistor R7 is connected to one end of the sixth resistor R6;

[0111] an eighth resistor R8, one end of the eighth resistor R8 is connected to the other end of the seventh resistor R7, and the other end of the eighth resistor R8 is connected to the source of the switch tube Q1;

[0112] The first input pin of the third amplifier U3A is the input end of the fourth signal detection module 5, and the output pin of the third amplifier U3A is the output end of the fourth signal detection module 5;

[0113] The fourth pulse signal output by the switch tube Q1 is amplified by the third amplifier U3A and output to the control module 2.

[0114] Specifically, in the embodiment, since the fourth signal detection module 5 does not obtain the fourth pulse signal by the way of coupling inductance through a capacitor, no transient suppression diode is arranged.

[0115] Preferably, the third amplifier U3A is arranged to amplify the fourth pulse signal, considering that the fourth pulse signal can be too low.

[0116] In the preferred embodiment of the present application, the switch tube Q1 is a P-channel field effect tube.

[0117] In the preferred embodiment of the present application, the lamp module 6 comprises:

[0118] A ninth resistor R9, one end of the ninth resistor R9 is connected to the second signal detection module 3;

[0119] A light emitting diode D1, the positive electrode of the light emitting diode D1 is connected to the other end of the ninth resistor R9, and the negative electrode of the light emitting diode D1 is connected to the drain of the switch tube Q1;

[0120] One end of the ninth resistor R9 serves as the input end of the lamp module 6, and the negative electrode of the light emitting diode D1 serves as the output end of the lamp module 6.

[0121] In the preferred embodiment of the present application, the control module 2 comprises:

[0122] A first control unit 21, configured to control the state display module 7 to prompt that the lamp module 6 is in an open circuit state when the first pulse signal is at a low value and no second pulse signal is received, and control the state display module 7 to prompt that the lamp module 6 is in a conduction state when the first pulse signal is at a high value;

[0123] A second control unit 22, configured to control the switch tube Q1 to be turned off and control the state display module 7 to prompt that the lamp module 6 is in a short circuit state when the second pulse signal is received;

[0124] A third control unit 23, configured to control the state display module 7 to prompt that the lamp module 6 is in a dimming state when the third pulse signal is received;

[0125] A fourth control unit 24, configured to control the switch tube Q1 to be turned off and control the state display module 7 to prompt that the lamp module 6 is in an over-power state when the fourth pulse signal is received.

[0126] The above description is only the preferred embodiment of the present application, and is not intended to limit the implementation and protection scope of the present application. Those skilled in the art should be able to realize that any equivalent replacement and obvious changes made according to the present application and the drawings should be included in the protection scope of the present application.

Claims

1. A luminaire fault detection circuit, characterized by, The application relates to a lamp control circuit, which comprises the following parts: a first signal detection module, a second signal detection module, a third signal detection module, a fourth signal detection module, a lamp module and a control module. The first input end of the first signal detection module is connected with the output end of a transformer, the second input end of the first signal detection module is connected with the source electrode of a switch tube, the output end of the first signal detection module is connected with the first input end of a control module, and the first signal detection module is used for detecting a first pulse signal and outputting the first pulse signal. The input end of the second signal detection module is connected with the source electrode of the switch tube, the output end of the second signal detection module is connected with the second input end of the control module, and the second signal detection module is used for detecting a second pulse signal and outputting the second pulse signal when a short circuit occurs in the circuit. The input end of the third signal detection module is connected with the source electrode of the switch tube, the output end of the third signal detection module is connected with the third input end of the control module, and the third signal detection module is used for detecting a third pulse signal and outputting the third pulse signal. The input end of the fourth signal detection module is connected with the source electrode of the switch tube, the output end of the fourth signal detection module is connected with the fourth input end of the control module, and the fourth signal detection module is used for detecting a fourth pulse signal and outputting the fourth pulse signal. The input end of the lamp module is connected with the second signal detection module, and the output end of the lamp module is connected with the drain electrode of the switch tube. The control module is further connected with a state display module, and the control module is used for controlling the state display module to display corresponding states according to the first pulse signal, the second pulse signal, the third pulse signal and the fourth pulse signal. When the lamp is a non-dimming lamp, the first signal detection module judges whether the lamp is in an open circuit state by detecting the pulse number of the first pulse signal. When the lamp is a dimming lamp, the third signal detection module analyzes the dimming state of the lamp and controls the on-off of the switch tube by detecting the waveform of the third pulse signal of the dimming lamp at different dimming depths. The third signal detection module comprises a third transient voltage suppression diode, a fifth resistor, a third capacitor and a second amplifier. The positive electrode of the third transient voltage suppression diode is connected with the source electrode of the switch tube, the negative electrode of the third transient voltage suppression diode is connected with the control module, one end of the fifth resistor is connected with the negative electrode of the third transient voltage suppression diode, the other end of the fifth resistor is connected with the positive electrode of the third transient voltage suppression diode, one end of the third capacitor is connected with one end of the fifth resistor, and the other end of the third capacitor is connected with the drain electrode of the switch tube. The first input pin of the second amplifier is connected with the negative electrode of the third transient voltage suppression diode, the second input pin of the second amplifier is connected with an external second power supply, and the output pin of the second amplifier is connected with the control module. The positive electrode of the third transient voltage suppression diode is used as the input end of the third signal detection module, and the output pin of the second amplifier is used as the output end of the third signal detection module. ​ ​ The third capacitor is coupled to inductively detect the third pulse signal and output the third pulse signal to the second amplifier for amplification, and the amplified third pulse signal is output to the control module through the second amplifier; The lamp module comprises: A ninth resistor, one end of the ninth resistor is connected to the second signal detection module; A light emitting diode, the anode of the light emitting diode is connected to the other end of the ninth resistor, and the cathode of the light emitting diode is connected to the drain of the switch tube; One end of the ninth resistor serves as an input terminal of the lamp module, and the cathode of the light emitting diode serves as an output terminal of the lamp module.

2. The lamp failure detection circuit of claim 1, wherein, The first signal detection module comprises: A first rectifier tube, the drain of the first rectifier tube is connected to the first output terminal of the transformer; A second rectifier tube, the source of the second rectifier tube is connected to the source of the first rectifier tube, and the drain of the second rectifier tube is connected to the second output terminal of the transformer; A first transient suppression diode, the anode of the first transient suppression diode is connected to the source of the switch tube, and the cathode of the first transient suppression diode is connected to the control module; A first resistor, one end of the first resistor is connected to the cathode of the first transient suppression diode, and the other end of the first resistor is connected to the anode of the first transient suppression diode; A second resistor, one end of the second resistor is connected to one end of the first resistor, and the other end of the second resistor is connected to an external first power supply; A first capacitor, one end of the first capacitor is connected to one end of the first resistor, and the other end of the first capacitor is connected to the drain of the second rectifier tube; The drain of the first rectifier tube serves as a first input terminal of the first signal detection module, the anode of the first transient suppression diode serves as a second input terminal of the first signal detection module, and the cathode of the first transient suppression diode serves as an output terminal of the first signal detection module; The first capacitor is coupled to inductively detect the first pulse signal and convert the first pulse signal into a forward pulse signal through the first transient suppression diode and output the forward pulse signal to the control module.

3. The lamp failure detection circuit of claim 2, wherein, The first rectifier tube and the second rectifier tube are P-channel field effect tubes.

4. The lamp failure detection circuit of claim 2, wherein, The first power supply is a 3.3-volt power supply.

5. The lamp failure detection circuit of claim 1, wherein, The second signal detection module comprises: A second transient suppression diode, the anode of the second transient suppression diode is connected to the source of the switch tube, and the cathode of the second transient suppression diode is connected to the control module; A third resistor, one end of the third resistor is connected to the cathode of the second transient suppression diode, and the other end of the third resistor is connected to the anode of the second transient suppression diode; A fourth resistor, one end of the fourth resistor is connected to one end of the third resistor, and the other end of the fourth resistor is connected to the input terminal of the lamp module; A second capacitor, one end of the second capacitor is connected to one end of the fourth resistor, and the other end of the second capacitor is connected to the other end of the fourth resistor; a first amplifier, a first input pin of the first amplifier is connected with an external second power supply, a second input pin of the first amplifier is connected with one end of the second capacitor, and an output pin of the first amplifier is connected with the control module; a positive electrode of the second transient voltage suppressor is used as an input end of the second signal detection module, and the output pin of the first amplifier is used as an output end of the second signal detection module; the second capacitor is coupled to inductively detect the second pulse signal and output the second pulse signal to the first amplifier for amplification, and the first amplifier outputs the amplified second pulse signal to the control module.

6. The lamp failure detection circuit of claim 1, wherein, the fourth signal detection module comprises: a third amplifier, a first input pin of the third amplifier is connected with a source electrode of the switch tube, and an output pin of the third amplifier is connected with the control module; a sixth resistor, one end of the sixth resistor is connected with a second input pin of the third amplifier, and the other end of the sixth resistor is connected with an external second power supply; a seventh resistor, one end of the seventh resistor is connected with one end of the sixth resistor; an eighth resistor, one end of the eighth resistor is connected with the other end of the seventh resistor, and the other end of the eighth resistor is connected with the source electrode of the switch tube; the first input pin of the third amplifier is used as an input end of the fourth signal detection module, and the output pin of the third amplifier is used as an output end of the fourth signal detection module; the third amplifier amplifies the fourth pulse signal output by the switch tube and outputs the amplified fourth pulse signal to the control module.

7. The lamp failure detection circuit of claim 1, wherein, The switch tube is a P-channel field effect tube.

8. The lamp failure detection circuit of claim 1, wherein, The control module comprises: a first control unit, configured to control the state display module to prompt that the lamp module is in an open circuit state when the first pulse signal is in a low value and the second pulse signal is not received, and control the state display module to prompt that the lamp module is in a conduction state when the first pulse signal is in a high value; a second control unit, configured to control the switch tube to be turned off and control the state display module to prompt that the lamp module is in a short circuit state when the second pulse signal is received; a third control unit, configured to control the state display module to prompt that the lamp module is in a dimming state when the third pulse signal is received; a fourth control unit, configured to control the switch tube to be turned off and control the state display module to prompt that the lamp module is in an over-power state when the fourth pulse signal is received.

Images