Trigger circuit of xenon-mercury lamp
By designing a trigger circuit including input capacitor, PWM control unit, transformer unit, rectifying filter unit and anti-return unit, the mercury xenon lamp is triggered by continuous DC high voltage, the problems of multiple triggering and electromagnetic interference in the prior art are solved. , achieving efficient and safe triggering effect.
Patent Information
- Application Number
- CN202310959164.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-01
- Publication Date
- 2025-02-14
AI Technical Summary
The trigger circuit of existing mercury xenon lamps requires multiple triggers to light up, and high pulse voltages are likely to cause electromagnetic interference to surrounding electronic products, affecting the life of the lamp.
A trigger circuit including input capacitor, PWM control unit, voltage transformer unit, rectifying filter unit and anti-return unit is designed. The mercury xenon lamp is triggered through continuous DC high voltage, and the voltage is only about 3kV, which significantly reduces electromagnetic interference.
The mercury xenon lamp can be lit at one time, reducing electromagnetic interference, extending the service life of the lamp, and reducing operating costs.
Smart Images
Figure CN119450841A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of lamp power supply circuits, and in particular to a trigger circuit for a mercury-xenon lamp. Background Art
[0002] At present, most of the triggering schemes for short-arc mercury-xenon lamps use high pulse voltage for triggering. The pulse voltage is generally as high as 20kV-50kV, which is easy to cause electromagnetic interference to surrounding electronic products at the moment of triggering. In addition, the pulse width of the pulse voltage can generally only last for about 1us, which is very short and easily affected by external interference, causing the mercury-xenon lamp to fail to trigger. Therefore, it often takes multiple triggers to successfully light the lamp, but multiple triggers have a greater impact on the life of the mercury-xenon lamp. Summary of the invention
[0003] The purpose of the present invention is to provide a trigger circuit for a mercury-xenon lamp, which can light up the mercury-xenon lamp with one trigger, which is beneficial to the protection of the mercury-xenon lamp, and has a low trigger voltage, which greatly reduces the electromagnetic interference to surrounding electronic products.
[0004] To achieve the above-mentioned object, the present invention discloses a trigger circuit of a mercury-xenon lamp, which is arranged at the output end of a DC power supply, and comprises an input capacitor, a PWM control unit, a transformer unit, a rectifier and filter unit, and an anti-backflow unit; the two ends of the input capacitor are respectively connected to the positive electrode and the negative electrode of the output end of the DC power supply; the PWM control unit is connected to the output end of the DC power supply, one end of the primary side of the transformer unit is connected to the positive electrode of the output end of the DC power supply, and the other end of the primary side of the transformer unit is connected to the negative electrode of the output end of the DC power supply via the PWM control unit; the secondary side of the transformer unit is connected to the mercury-xenon lamp via the rectifier and filter unit; the positive electrode of the input end of the mercury-xenon lamp is also connected to the positive electrode of the output end of the DC power supply via the anti-backflow unit, and the negative electrode of the input end of the mercury-xenon lamp is also connected to the negative electrode of the output end of the DC power supply; The PWM control unit samples the output voltage at the output end of the DC power supply, and when the sampled output voltage is higher than the set value, the PWM control unit chops the primary side voltage of the transformer unit into a high-frequency DC square wave voltage, and the high-frequency DC square wave voltage forms a continuous DC high voltage after passing through the rectification and filtering unit and is loaded on the input end of the mercury xenon lamp until the mercury xenon lamp is lit; after the mercury xenon lamp is lit, the anti-backflow unit continues the current of the mercury xenon lamp, and at the same time, the PWM control unit cuts off the primary side circuit of the transformer unit.
[0005] Preferably, the PWM control unit includes a sampling resistor R1, a sampling resistor R2, a PWM generator U1 and a transistor Q1, one end of the sampling resistor R1 is connected to the positive electrode of the output end of the DC power supply, one end of the sampling resistor R2 is connected to the negative electrode of the output end of the DC power supply, the other end of the sampling resistor R1 and the other end of the sampling resistor R2 are connected to the input end of the PWM generator U1, the output end of the PWM generator U1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the negative electrode of the output end of the DC power supply, and the collector of the transistor Q1 is connected to one end of the primary side of the transformer unit.
[0006] Preferably, the PWM generator model is UC3842.
[0007] Preferably, the rectifier and filter unit includes a diode D1 and a capacitor C2, the anode of the diode D1 is connected to one end of the secondary side of the transformer unit, the cathode of the diode D1 is connected to one end of the capacitor C2 and the positive input end of the mercury-xenon lamp; the other end of the capacitor C2 is connected to the other end of the secondary side of the transformer unit and the negative input end of the mercury-xenon lamp.
[0008] Preferably, the backflow prevention unit comprises a diode D2, an anode of the diode D2 is connected to the positive electrode of the output terminal of the DC power supply, and a cathode of the diode D2 is connected to the positive electrode of the input terminal of the mercury-xenon lamp.
[0009] The present invention has the following beneficial effects: After the trigger circuit of the present invention is connected to the DC power supply, as the input capacitor stores energy, the output voltage of the DC power supply increases. When the output voltage sampled by the PWM control unit is higher than the setting, the PWM control unit chops the primary side voltage of the transformer unit into a high-frequency DC square wave voltage. After the high-frequency DC square wave voltage is boosted, rectified and filtered, it forms a continuous DC high voltage and is loaded on the input end of the mercury xenon lamp. When the DC high voltage is greater than the trigger voltage of the mercury xenon lamp, the lamp tube can be lit. After the lamp tube is lit, the voltage at both ends of the lamp tube is instantly reduced, and the DC power supply can continue the current to the lamp tube through the anti-backflow unit, and the output voltage of the DC power supply will be clamped to about the actual voltage value of the lamp tube. In addition, after the lamp tube is lit, the voltage sampled by the PWM control unit is reduced, that is, it is judged that the lamp tube is lit successfully, and the PWM control unit cuts off the primary side circuit of the transformer unit. The present invention uses a continuous DC high voltage to trigger the mercury xenon lamp. The DC voltage only needs to be about 3kV, which is much lower than the trigger voltage of the existing trigger circuit. It is safer to use and greatly reduces the electromagnetic interference to the surrounding electronic products at the moment of triggering. Moreover, the DC voltage is continuously applied to both ends of the lamp tube until the lamp tube is successfully triggered. The triggering success rate can reach 100%, which can extend the service life of the mercury xenon lamp. In addition, the trigger mechanism of the present invention does not need to use a discharge tube, and the discharge tube has a life limit. The present invention does not have this problem and can further reduce the operating cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a schematic diagram of the present invention. DETAILED DESCRIPTION
[0011] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.
[0012] like Figure 1 As shown, the present invention discloses a trigger circuit of a mercury-xenon lamp, which is arranged at the output end of a DC power supply, and includes an input capacitor C1, a PWM control unit, a transformer unit T1, a rectifier filter unit, and an anti-backflow unit. The two ends of the input capacitor C1 are respectively connected to the output positive electrode Vin+ and the output negative electrode Vin- of the DC power supply. The PWM control unit is connected to the output end Vin of the DC power supply, one end of the primary side of the transformer unit T1 is connected to the output positive electrode Vin+ of the DC power supply, and the other end of the primary side of the transformer unit T1 is connected to the output negative electrode Vin- of the DC power supply via the PWM control unit. The secondary side of the transformer unit T1 is connected to the mercury-xenon lamp LAMP via the rectifier filter unit. The input positive electrode Vlamp+ of the mercury-xenon lamp LAMP is also connected to the output positive electrode Vin+ of the DC power supply via the anti-backflow unit, and the input negative electrode Vlamp- of the mercury-xenon lamp LAMP is also connected to the output negative electrode Vin- of the DC power supply.
[0013] Specifically, the PWM control unit includes a sampling resistor R1, a sampling resistor R2, a PWM generator U1 and a transistor Q1, and the model of the PWM generator U1 is UC3842. One end of the sampling resistor R1 is connected to the positive electrode Vin+ of the output end of the DC power supply, one end of the sampling resistor R2 is connected to the negative electrode Vin- of the output end of the DC power supply, the other end of the sampling resistor R1 and the other end of the sampling resistor R2 are connected to the input end of the PWM generator U1, the output end of the PWM generator U1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the negative electrode of the output end of the DC power supply, and the collector of the transistor Q1 is connected to one end of the primary side of the transformer unit T1.
[0014] The rectifier and filter unit includes a diode D1 and a capacitor C2, wherein the anode of the diode D1 is connected to one end of the secondary side of the transformer unit T1, the cathode of the diode D1 is connected to one end of the capacitor C2 and the positive input terminal Vlamp+ of the mercury-xenon lamp LAMP; the other end of the capacitor C2 is connected to the other end of the secondary side of the transformer unit T1 and the negative input terminal Vlamp- of the mercury-xenon lamp LAMP.
[0015] The backflow prevention unit includes a diode D2, an anode of the diode D2 is connected to the positive electrode Vin+ of the output terminal of the DC power supply, and a cathode of the diode D2 is connected to the positive electrode Vlamp+ of the input terminal of the mercury-xenon lamp LAMP.
[0016] The key point of the present invention is that after the trigger circuit of the present invention is connected to the DC power supply, as the input capacitor stores energy, the output voltage of the DC power supply increases. When the output voltage sampled by the PWM control unit is higher than the setting, the PWM control unit chops the primary side voltage of the transformer unit into a high-frequency DC square wave voltage. After the high-frequency DC square wave voltage is boosted, rectified and filtered, it forms a continuous DC high voltage and is loaded on the input end of the mercury xenon lamp. When the DC high voltage is greater than the trigger voltage of the mercury xenon lamp, the lamp tube can be lit. After the lamp tube is lit, the voltage at both ends of the lamp tube is instantly reduced, and the DC power supply can continue the current to the lamp tube through the anti-backflow unit, and the output voltage of the DC power supply will be clamped to about the actual voltage value of the lamp tube. In addition, after the lamp tube is lit, the voltage sampled by the PWM control unit is reduced, that is, it is judged that the lamp tube is lit successfully, and the PWM control unit cuts off the primary side circuit of the transformer unit. The present invention uses a continuous DC high voltage to trigger the mercury xenon lamp. The DC voltage only needs to be about 3kV, which is much lower than the trigger voltage of the existing trigger circuit. It is safer to use and greatly reduces the electromagnetic interference to the surrounding electronic products at the moment of triggering. Moreover, the DC voltage is continuously applied to both ends of the lamp tube until the lamp tube is successfully triggered. The triggering success rate can reach 100%, which can extend the service life of the mercury xenon lamp. In addition, the trigger mechanism of the present invention does not need to use a discharge tube, and the discharge tube has a life limit. The present invention does not have this problem and can further reduce the operating cost.
[0017] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.
Claims
1. A trigger circuit for a mercury-xenon lamp, arranged at the output end of a DC power supply, characterized in that: It includes an input capacitor, a PWM control unit, a transformer unit, a rectifier and filter unit, and an anti-backflow unit; the two ends of the input capacitor are respectively connected to the positive output terminal and the negative output terminal of a DC power supply; the PWM control unit is connected to the output terminal of the DC power supply, one end of the primary side of the transformer unit is connected to the positive output terminal of the DC power supply, and the other end of the primary side of the transformer unit is connected to the negative output terminal of the DC power supply via the PWM control unit; the secondary side of the transformer unit is connected to a mercury-xenon lamp via the rectifier and filter unit; the positive input terminal of the mercury-xenon lamp is also connected to the positive output terminal of the DC power supply via the anti-backflow unit, and the negative input terminal of the mercury-xenon lamp is also connected to the negative output terminal of the DC power supply; The PWM control unit samples the output voltage at the output end of the DC power supply, and when the sampled output voltage is higher than the set value, the PWM control unit chops the primary side voltage of the transformer unit into a high-frequency DC square wave voltage, and the high-frequency DC square wave voltage forms a continuous DC high voltage after passing through the rectification and filtering unit and is loaded on the input end of the mercury xenon lamp until the mercury xenon lamp is lit; after the mercury xenon lamp is lit, the anti-backflow unit continues the current of the mercury xenon lamp, and at the same time, the PWM control unit cuts off the primary side circuit of the transformer unit.
2. The trigger circuit of the mercury-xenon lamp according to claim 1, characterized in that: The PWM control unit includes a sampling resistor R1, a sampling resistor R2, a PWM generator U1 and a transistor Q1, one end of the sampling resistor R1 is connected to the positive electrode of the output end of the DC power supply, one end of the sampling resistor R2 is connected to the negative electrode of the output end of the DC power supply, the other end of the sampling resistor R1 and the other end of the sampling resistor R2 are connected to the input end of the PWM generator U1, the output end of the PWM generator U1 is connected to the base of the transistor Q1, the emitter of the transistor Q1 is connected to the negative electrode of the output end of the DC power supply, and the collector of the transistor Q1 is connected to one end of the primary side of the transformer unit.
3. The trigger circuit of the mercury-xenon lamp according to claim 2, characterized in that: The PWM generator model is UC3842.
4. The trigger circuit of the mercury-xenon lamp according to claim 1, characterized in that: The rectifier and filter unit includes a diode D1 and a capacitor C2, wherein the anode of the diode D1 is connected to one end of the secondary side of the transformer unit, the cathode of the diode D1 is connected to one end of the capacitor C2 and the positive input terminal of the mercury-xenon lamp; the other end of the capacitor C2 is connected to the other end of the secondary side of the transformer unit and the negative input terminal of the mercury-xenon lamp.
5. The trigger circuit of the mercury-xenon lamp according to claim 1, characterized in that: The backflow prevention unit includes a diode D2, an anode of the diode D2 is connected to the positive electrode of the output end of the DC power supply, and a cathode of the diode D2 is connected to the positive electrode of the input end of the mercury-xenon lamp.