Xenon lamp power supply output control circuit

Abstract

The utility model discloses a xenon lamp power supply output control circuit, and belongs to the field of switching power supplies. The circuit comprises a PWM control chip. An inverter circuit; the transformer comprises a primary winding, a first secondary winding and a second secondary winding; a first output control circuit; the output end of the PWM control chip is connected with the input end of the inverter circuit; the output end of the inverter circuit is connected with the input end of the primary winding, and the output end of the first secondary winding is connected with the input end of the first output control circuit; the output end of the second secondary winding is connected with the input end of the second output control circuit; the output end of the first output control circuit and the output end of the second output control circuit are connected in parallel and then a terminal is led out as the output end of the xenon lamp power supply output control circuit. According to the utility model, the voltage and current requirements of the xenon lamp in normal working and starting stages are met through different transformer winding loops, and the stability and efficiency of the power supply control circuit are improved at the same time.

Description

Technical Field

[0001] The utility model belongs to the field of switching power supply, and specifically relates to a xenon lamp power supply output control circuit. Background Art

[0002] With the continuous innovation of technology, xenon lamps are widely used in many fields such as color inspection of cloth and fabrics, aging test of plastics, and solar simulators for aerospace because of their advantages such as high luminous efficiency, low energy waste, and approximate point light source. The switching power supply that powers the xenon lamp is the core component of the xenon lamp product, which is directly related to the output capacity, stability, energy consumption and other key parameters of the xenon lamp product. Therefore, it is particularly important to design a circuit that can efficiently and stably control the power output.

[0003] The switching power supply that powers the xenon lamp needs to output high voltage and low current during the startup phase, and low voltage and high current during the normal working phase. Most of the existing xenon lamp power supply control circuits use a single transformer winding output, and increase the adjustable range of the output voltage and current by reducing the transformer primary-to-secondary turns ratio and the duty cycle of the drive signal to simultaneously meet the output requirements of the xenon lamp, which are very different in the two startup phases and the normal working phase. However, this solution reduces the transformer ratio and the duty cycle of the drive signal, which will result in low power efficiency and poor stability. At this time, a more complete circuit is needed to efficiently and stably achieve the special output requirements of the xenon lamp.

[0004] The comparative document (CN219740655U) discloses a pulse xenon lamp power supply control circuit, which can increase the voltage more safely and stably according to the discharge characteristics of the pulse flashing xenon lamp to reach the voltage value for lighting the pulse xenon lamp; the control circuit uses a single-chip microcomputer to design the circuit, which can more conveniently and safely control the xenon lamp flashing frequency pulse xenon lamp power supply control circuit, and can solve the frequency control problem of the pulse xenon lamp, thereby improving the working effect of the pulse xenon lamp.

[0005] This comparative document mainly uses a single-chip microcomputer to control the power supply of the xenon lamp, and does not address the requirements for the power supply control of the xenon lamp when a transformer is used, which is qualitatively different from the present utility model. Utility Model Content

[0006] The utility model aims to overcome the deficiencies of the prior art and proposes a xenon lamp power output control circuit to achieve the following purposes: to meet the voltage and current requirements of the xenon lamp in normal operation and startup stages through different transformer winding loops, while improving the stability and efficiency of the power control circuit.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a xenon lamp power supply output control circuit, the xenon lamp power supply output control circuit includes a PWM control chip; an inverter circuit; a transformer, including a primary winding, a first secondary winding, and a second secondary winding; a first output control circuit; a second output control circuit, wherein the number of turns of the first secondary winding is less than the number of turns of the second secondary winding, the output end of the PWM control chip is connected to the input end of the inverter circuit; the output end of the inverter circuit is connected to the input end of the primary winding, the output end of the first secondary winding is connected to the input end of the first output control circuit; the output end of the second secondary winding is connected to the input end of the second output control circuit; the output end of the first output control circuit is connected in parallel with the output end of the second output control circuit, and the lead-out terminal serves as the output end of the xenon lamp power supply output control circuit.

[0008] Preferably, the first output control circuit includes a first rectifier circuit, a second rectifier circuit, and an inductor L1, wherein the output end 3 of the first secondary winding is connected to the input end of the first rectifier circuit; the output end 4 of the first secondary winding is connected to the input end of the second rectifier circuit; the output end 5 of the first secondary winding is connected to one end of the inductor L1; the other end of the inductor L1 serves as the negative output end of the first output control circuit, and the output ends of the first rectifier circuit and the second rectifier circuit are connected in parallel as the positive output end of the first output control circuit.

[0009] Preferably, the first rectifier circuit includes a resistor R1, a capacitor C1, a diode group D1 connected in parallel in the same direction, and a diode group D2 connected in parallel in the same direction, wherein the following are connected in parallel between the input end and the output end of the first rectifier circuit: the diode group D1 connected in parallel in the same direction, configured such that the anode of D1 is connected to the input end of the first rectifier circuit, and the cathode of D1 is connected to the output end of the first rectifier circuit; the diode group D2 connected in parallel in the same direction, configured such that the anode of D2 is connected to the input end of the first rectifier circuit, and the cathode of D2 is connected to the output end of the first rectifier circuit; and the resistor R1 and capacitor C1 connected in series.

[0010] Preferably, the second rectifier circuit includes a resistor R2, a capacitor C2, a diode group D3 connected in parallel in the same direction, and a diode group D4 connected in parallel in the same direction, wherein the following are connected in parallel between the input end and the output end of the second rectifier circuit: a diode group D3 connected in parallel in the same direction, configured such that the anode of D3 is connected to the input end of the second rectifier circuit, and the cathode of D3 is connected to the output end of the second rectifier circuit; a diode group D4 connected in parallel in the same direction, configured such that the anode of D4 is connected to the input end of the second rectifier circuit, and the cathode of D4 is connected to the output end of the second rectifier circuit; and a resistor R2 and a capacitor C2 connected in series.

[0011] Preferably, the second output control circuit includes a diode D5, a diode D6, a capacitor C3, a capacitor C4, and an inductor L2, wherein the output end 6 of the second secondary winding is connected to the anode of the diode D5 through the capacitor C3; the output end 7 of the second secondary winding is connected to the anode of the diode D6 through the capacitor C4; the output end 8 of the second secondary winding is connected to one end of the inductor L2, and the other end of the inductor L2 serves as the negative output end of the second output control circuit; the cathode of the diode D5 and the cathode of the diode D6 are connected in parallel to serve as the positive output end of the second output control circuit.

[0012] Preferably, the output end 3 and the output end 4 of the first secondary winding are connected through a series resistor R3 and a capacitor C5, serving as an anti-peak circuit of the first output control circuit; the output end 6 and the output end 7 of the second secondary winding are connected through a series resistor R4 and a capacitor C6, serving as an anti-peak circuit of the second output control circuit.

[0013] Preferably, the xenon lamp power supply output control circuit includes a sampling resistor R5, an overcurrent sampling circuit, and an overcurrent protection circuit, wherein the negative output end of the second output control circuit is connected to one end of the sampling resistor R5, and the other end of the sampling resistor R5 serves as a new negative output end of the second output control circuit; the overcurrent sampling circuit is connected in parallel at both ends of the sampling resistor R5; and the overcurrent protection circuit is respectively connected to the overcurrent sampling circuit and the PWM control chip.

[0014] Preferably, the xenon lamp power supply output control circuit includes a sampling resistor R6, a current sampling circuit, and a first PID adjustment circuit, wherein the negative output end of the first output control circuit is connected in parallel with the negative output end of the second output control circuit and then connected to one end of the sampling resistor R6, and the other end of the sampling resistor R6 serves as the negative output end of the xenon lamp power supply output control circuit; the current sampling circuit is connected in parallel at both ends of the sampling resistor R6; and the first PID adjustment circuit is respectively connected to the current sampling circuit and the PWM control chip.

[0015] Preferably, the xenon lamp power supply output control circuit includes a voltage sampling circuit and a second PID adjustment circuit, wherein the voltage sampling circuit is connected in parallel to the output end of the xenon lamp power supply output control circuit; and the second PID adjustment circuit is connected to the voltage sampling circuit and the PWM control chip respectively.

[0016] The technical effects of the utility model are as follows: the utility model enables the xenon lamp to work through different transformer winding loops in the normal working stage and the starting stage respectively; increases the primary-to-secondary turns ratio of the transformer in the normal working stage, so that the voltage input to the primary winding of the transformer in this stage can be increased, thereby increasing the duty cycle of the driving signal in the normal working stage and increasing the efficiency of the power supply; at the same time, because capacitors and inductors with suitable parameters are added to the two output control circuits, the output current of the starting loop winding (the second secondary winding) is limited, and the stability and efficiency are also increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a xenon lamp power output control circuit according to an embodiment of the utility model.

[0018] Markings in the figure are: 1 and 2 represent the input ends of the primary winding of the transformer; 3-5 represent the output ends of the first secondary winding of the transformer; 6-8 represent the output ends of the second secondary winding of the transformer. DETAILED DESCRIPTION

[0019] The following is a further detailed description of the specific implementation of the utility model through the description of the embodiments with reference to the accompanying drawings, with the purpose of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the utility model concept and technical solution of the utility model, and to facilitate its implementation. In the utility model, the terms "first" and "second" are only used to facilitate the text description, and are not limited to this in actual implementation under the premise of ensuring the technical principles. In order to make the technical solution of the utility model clearer, the utility model is explained through the following embodiments:

[0020] A xenon lamp power supply output control circuit comprises a PWM control chip; an inverter circuit; a transformer, comprising a primary winding, a first secondary winding, and a second secondary winding; a first output control circuit; and a second output control circuit, wherein the number of turns of the first secondary winding is less than the number of turns of the second secondary winding, the output end of the PWM control chip is connected to the input end of the inverter circuit; the output end of the inverter circuit is connected to the input end of the primary winding, the output end of the first secondary winding is connected to the input end of the first output control circuit; the output end of the second secondary winding is connected to the input end of the second output control circuit; the output end of the first output control circuit and the output end of the second output control circuit are connected in parallel, and then a terminal is led out as the output end of the xenon lamp power supply output control circuit, and the output end is connected to a xenon lamp, thereby supplying power to the xenon lamp.

[0021] Specifically, IN+ and IN- are inputs from the inverter circuit to the primary winding of the transformer, wherein IN+ is loaded on the input terminal 1 of the primary winding of the transformer, and IN- is loaded on the input terminal 2 of the primary winding of the transformer. The PWM control chip sends a drive signal to the inverter circuit, and the PWM control chip controls the outputs IN+ and IN- of the inverter circuit by adjusting the duty cycle of the drive signal. The inverter circuit is a common method used by those skilled in the art, and this embodiment will not be described in detail here.

[0022] The transformer of this embodiment has only one winding at the primary side, but has two independent output windings with different turns ratios at the secondary side, wherein the first secondary winding has fewer turns and a higher turns ratio. When the IN+ voltage inputted by the primary turns is the same, the output voltage of this winding after rectification by the rectifier circuit is smaller, so it is the main winding that provides low voltage and high current for the normal working stage of the xenon lamp. This embodiment increases the turns ratio of the primary and secondary sides of the transformer during the normal working stage, so that the voltage inputted by the primary winding of the transformer at this stage can be larger, thereby increasing the duty cycle of the driving signal during the normal working stage and increasing the efficiency of the power supply. The second secondary winding has more turns and a lower turns ratio. When the IN+ voltage inputted by the primary is the same, the output voltage of this winding after rectification by the D7 / D8 rectifier diode is larger, so it is the main winding that provides high voltage and low current for the starting stage of the xenon lamp.

[0023] In this embodiment, the first secondary winding and the second secondary winding are rectified and outputted respectively by the corresponding output control circuits, and the rectified output ends are then connected in parallel as the output of the xenon lamp power supply output control circuit of this embodiment, wherein the positive output end of the first output control circuit and the positive output end of the second output control circuit are connected in parallel as the positive output end OUT+ of the xenon lamp power supply output control circuit of this embodiment; the negative output end of the second output control circuit and the negative output end of the second output control circuit are connected in parallel as the negative output end OUT- of the xenon lamp power supply output control circuit of this embodiment;

[0024] Specifically, the first output control circuit of the present embodiment includes a first rectifier circuit, a second rectifier circuit, and an inductor L1, wherein the output end 3 of the first secondary winding is connected to the input end of the first rectifier circuit; the output end 4 of the first secondary winding is connected to the input end of the second rectifier circuit; the output end 5 of the first secondary winding is connected to one end of the inductor L1; the other end of the inductor L1 serves as the negative output end of the first output control circuit, and the output ends of the first rectifier circuit and the second rectifier circuit are connected in parallel to serve as the positive output end of the first output control circuit.

[0025] Preferably, the first rectifier circuit includes a resistor R1, a capacitor C1, a diode group D1 connected in parallel in the same direction, and a diode group D2 connected in parallel in the same direction. The diode group connected in parallel in the same direction of this embodiment is formed by two diodes connected in parallel in the same direction, that is, the anodes of the two diodes are connected to each other, and the cathodes are connected to each other. The first rectifier circuit of this embodiment is connected in parallel between the input end and the output end: the diode group D1 connected in parallel in the same direction, configured such that the anode of D1 is connected to the input end of the first rectifier circuit, and the cathode of D1 is connected to the output end of the first rectifier circuit; the diode group D2 connected in parallel in the same direction, configured such that the anode of D2 is connected to the input end of the first rectifier circuit, and the cathode of D2 is connected to the output end of the first rectifier circuit; the resistor R1 and the capacitor C1 connected in series.

[0026] Similarly, the second rectifier circuit includes a resistor R2, a capacitor C2, a diode group D3 connected in parallel in the same direction, and a diode group D4 connected in parallel in the same direction, wherein the second rectifier circuit is connected in parallel with: a diode group D3 connected in parallel in the same direction, configured such that the anode of D3 is connected to the input end of the second rectifier circuit, and the cathode of D3 is connected to the output end of the second rectifier circuit; a diode group D4 connected in parallel in the same direction, configured such that the anode of D4 is connected to the input end of the second rectifier circuit, and the cathode of D4 is connected to the output end of the second rectifier circuit; and a resistor R2 and a capacitor C2 connected in series.

[0027] The second output control circuit of this embodiment includes a diode D5, a diode D6, a capacitor C3, a capacitor C4, and an inductor L2, wherein the output terminal 6 of the second secondary winding is connected to the anode of the diode D5 through the capacitor C3; the output terminal 7 of the second secondary winding is connected to the anode of the diode D6 through the capacitor C4; the output terminal 8 of the second secondary winding is connected to one end of the inductor L2, and the other end of the inductor L2 serves as the negative output terminal of the second output control circuit; the cathode of the diode D5 and the cathode of the diode D6 are connected in parallel to serve as the positive output terminal of the second output control circuit.

[0028] In this embodiment, by calculating and adding capacitors C3 / C4 and inductors L1 / L2 with appropriate parameters in the two output control circuits, the output current of the second secondary winding (starting loop winding) can be effectively limited, thereby increasing the stability of the power supply.

[0029] In addition, in this embodiment, an RC circuit is provided at the output end of the first secondary winding and the second secondary winding as an anti-peak circuit of the corresponding output control circuit to ensure the circuit safety during rectification of the output control circuit. Specifically, the output end 3 and the output end 4 of the first secondary winding are connected through a series resistor R3 and a capacitor C5, as an anti-peak circuit of the first output control circuit; the output end 6 and the output end 7 of the second secondary winding are connected through a series resistor R4 and a capacitor C6, as an anti-peak circuit of the second output control circuit.

[0030] The xenon lamp power supply output control circuit of this embodiment also includes a sampling resistor R5, an overcurrent sampling circuit, and an overcurrent protection circuit, wherein the negative output end of the second output control circuit is connected to one end of the sampling resistor R5, and the other end of the sampling resistor R5 serves as a new negative output end of the second output control circuit; the overcurrent sampling circuit is connected in parallel to both ends of the sampling resistor R5; and the overcurrent protection circuit is connected to the overcurrent sampling circuit and the PWM control chip, respectively. This embodiment performs overcurrent sampling at the resistor R5 and outputs an overcurrent sampling signal overcurrent protection circuit, and then compares the overcurrent sampling signal with the overcurrent reference signal through the overcurrent protection circuit, and the comparison result is fed back to the PWM control chip, and the PWM control chip promptly shuts off the drive signal when an overcurrent fault occurs according to the comparison result, thereby ensuring the safety of the circuit.

[0031] The xenon lamp power supply output control circuit of this embodiment also includes a sampling resistor R6, a current sampling circuit, and a first PID adjustment circuit, wherein the negative output terminal of the first output control circuit is connected in parallel with the negative output terminal of the second output control circuit and then connected to one end of the sampling resistor R6, and the other end of the sampling resistor R6 serves as the negative output terminal of the xenon lamp power supply output control circuit; the current sampling circuit is connected in parallel at both ends of the sampling resistor R6; and the first PID adjustment circuit is connected to the current sampling circuit and the PWM control chip respectively. When the xenon lamp is started and works normally, the normal working loop with low voltage and high current is the main output loop of the power supply. At this time, the xenon lamp load is in a closed-loop state. At this time, current sampling is performed at the sampling point of the resistor R6. After receiving the current sampling signal and the current reference signal, the first PID adjustment circuit performs PID adjustment and feeds back the PID adjustment control signal to the PWM control chip, so that the PWM control chip adjusts the duty cycle of the drive signal of the control inverter circuit according to the control signal to realize current closed-loop control.

[0032] The xenon lamp power supply output control circuit of this embodiment includes a voltage sampling circuit and a second PID adjustment circuit, wherein the voltage sampling circuit is connected in parallel to the output end (OUT+ and OUT-) of the xenon lamp power supply output control circuit; the second PID adjustment circuit is connected to the voltage sampling circuit and the PWM control chip respectively. When the xenon lamp is just turned on, the high voltage and low current startup circuit is the main output circuit of the power supply. At this time, the xenon lamp load is in an open-loop state, and the output voltage will be pulled up all the time. Then, the OUT+ and OUT- voltages are sampled, and the second PID adjustment circuit receives the voltage sampling signal and the voltage reference signal, performs PID adjustment, and feeds back the PID adjustment control signal to the PWM control chip, so that the PWM control chip adjusts the duty cycle of the drive signal of the inverter circuit according to the control signal to realize voltage closed-loop control. The current / voltage sampling circuit, PID adjustment circuit, and overcurrent protection circuit are commonly used by those skilled in the art, and this embodiment will not be repeated here.

[0033] The above is an exemplary description of the utility model in conjunction with the accompanying drawings. Obviously, the specific implementation of the utility model is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the utility model; or the above concept and technical solution of the utility model are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A xenon lamp power output control circuit, characterized in that: The xenon lamp power supply output control circuit includes a PWM control chip; an inverter circuit; a transformer, including a primary winding, a first secondary winding, and a second secondary winding; a first output control circuit; and a second output control circuit, wherein the number of turns of the first secondary winding is less than the number of turns of the second secondary winding, and the output end of the PWM control chip is connected to the input end of the inverter circuit; the output end of the inverter circuit is connected to the input end of the primary winding, and the output end of the first secondary winding is connected to the input end of the first output control circuit; the output end of the second secondary winding is connected to the input end of the second output control circuit; the output end of the first output control circuit is connected in parallel with the output end of the second output control circuit, and the lead terminal serves as the output end of the xenon lamp power supply output control circuit.

2. A xenon lamp power output control circuit according to claim 1, characterized in that: The first output control circuit comprises a first rectifier circuit, a second rectifier circuit, and an inductor L1, wherein the output end (3) of the first secondary winding is connected to the input end of the first rectifier circuit; the output end (4) of the first secondary winding is connected to the input end of the second rectifier circuit; the output end (5) of the first secondary winding is connected to one end of the inductor L1; the other end of the inductor L1 serves as the negative output end of the first output control circuit, and the output ends of the first rectifier circuit and the second rectifier circuit are connected in parallel to serve as the positive output end of the first output control circuit.

3. A xenon lamp power output control circuit according to claim 2, characterized in that: The first rectifier circuit includes a resistor R1, a capacitor C1, a diode group D1 connected in parallel in the same direction, and a diode group D2 connected in parallel in the same direction, wherein the following are connected in parallel between the input end and the output end of the first rectifier circuit: the diode group D1 connected in parallel in the same direction, configured such that the anode of D1 is connected to the input end of the first rectifier circuit, and the cathode of D1 is connected to the output end of the first rectifier circuit; the diode group D2 connected in parallel in the same direction, configured such that the anode of D2 is connected to the input end of the first rectifier circuit, and the cathode of D2 is connected to the output end of the first rectifier circuit; and the resistor R1 and capacitor C1 connected in series.

4. The xenon lamp power output control circuit according to claim 3, characterized in that: The second rectifier circuit includes a resistor R2, a capacitor C2, a diode group D3 connected in parallel in the same direction, and a diode group D4 connected in parallel in the same direction, wherein the following are connected in parallel between the input end and the output end of the second rectifier circuit: a diode group D3 connected in parallel in the same direction, configured such that the anode of D3 is connected to the input end of the second rectifier circuit, and the cathode of D3 is connected to the output end of the second rectifier circuit; a diode group D4 connected in parallel in the same direction, configured such that the anode of D4 is connected to the input end of the second rectifier circuit, and the cathode of D4 is connected to the output end of the second rectifier circuit; and a resistor R2 and a capacitor C2 connected in series.

5. The xenon lamp power output control circuit according to claim 1, characterized in that: The second output control circuit comprises a diode D5, a diode D6, a capacitor C3, a capacitor C4, and an inductor L2, wherein the output end (6) of the second secondary winding is connected to the anode of the diode D5 through the capacitor C3; the output end (7) of the second secondary winding is connected to the anode of the diode D6 through the capacitor C4; the output end (8) of the second secondary winding is connected to one end of the inductor L2, and the other end of the inductor L2 serves as the negative output end of the second output control circuit; the cathode of the diode D5 and the cathode of the diode D6 are connected in parallel to serve as the positive output end of the second output control circuit.

6. A xenon lamp power output control circuit according to any one of claims 2, 3, 4 and 5, characterized in that: The output end (3) and the output end (4) of the first secondary winding are connected via a series resistor R3 and a capacitor C5, serving as an anti-peak circuit of the first output control circuit; the output end (6) and the output end (7) of the second secondary winding are connected via a series resistor R4 and a capacitor C6, serving as an anti-peak circuit of the second output control circuit.

7. A xenon lamp power output control circuit according to any one of claims 1 to 5, characterized in that: The xenon lamp power supply output control circuit includes a sampling resistor R5, an overcurrent sampling circuit, and an overcurrent protection circuit, wherein the negative output end of the second output control circuit is connected to one end of the sampling resistor R5, and the other end of the sampling resistor R5 serves as a new negative output end of the second output control circuit; the overcurrent sampling circuit is connected in parallel at both ends of the sampling resistor R5; and the overcurrent protection circuit is respectively connected to the overcurrent sampling circuit and the PWM control chip.

8. A xenon lamp power output control circuit according to any one of claims 1 to 5, characterized in that: The xenon lamp power supply output control circuit includes a sampling resistor R6, a current sampling circuit, and a first PID adjustment circuit, wherein the negative output end of the first output control circuit is connected in parallel with the negative output end of the second output control circuit and connected to one end of the sampling resistor R6, and the other end of the sampling resistor R6 serves as the negative output end of the xenon lamp power supply output control circuit; the current sampling circuit is connected in parallel at both ends of the sampling resistor R6; and the first PID adjustment circuit is respectively connected to the current sampling circuit and the PWM control chip.

9. A xenon lamp power output control circuit according to any one of claims 1 to 5, characterized in that: The xenon lamp power supply output control circuit includes a voltage sampling circuit and a second PID adjustment circuit, wherein the voltage sampling circuit is connected in parallel to the output end of the xenon lamp power supply output control circuit; the second PID adjustment circuit is connected to the voltage sampling circuit and the PWM control chip respectively.

Images