Control circuit with slow start switch and stage lamp with same

Abstract

The invention discloses a control circuit with a slow start switch and a stage lamp with the same, the control circuit with the slow start switch comprises a power supply, a post-stage load and an MCU used for outputting control voltage for starting the control circuit, the power supply is a constant-voltage power supply, and the post-stage load is connected with the MCU. The current limiting module is electrically connected with a post-stage load through a time delay switch and the current limiting module, and the time delay switch is a normally open switch; after the MCU outputs a control voltage, when the power supply is powered on, the current limiting module is conducted, and when the time delay switch is conducted, the current limiting module is automatically disconnected; wherein the limiting current module transmits a limiting current I3 to the rear-stage load, the anti-impact current of the power supply is I1, the anti-impact current of the time delay switch is I2, and the limiting current I3 is smaller than or equal to the minimum value of I1 and I2. The problem that the impulse current in the control circuit at the moment of power-on causes overload to the post-stage load or switch in the circuit is solved, and the post-stage load or switch can be started gently and safely by using the slow start function.

Description

Technical Field

[0001] The present invention relates to the technical field of lighting devices, and more particularly to a control circuit with a slow-start switch and a stage lamp with the control circuit. Background Art

[0002] In today's era of rapid technological development, stage lighting has become a complex lighting device that integrates a variety of lighting effects. Lamps usually contain multiple modules, mainly including light source modules that generate light and effect modules that intercept light beams to produce specific light spots. In order to ensure its stability during operation, it is usually necessary to add bypass capacitors or decoupling capacitors to the control circuit to filter out noise in the circuit. However, due to the capacitive characteristics of the capacitor, a large impact current will be generated at the moment of power-on, which may trigger overload protection. Moreover, more and more lamps have added protection auxiliary systems. When the lamps are abnormal, they will be shut down in time and restarted after the fault is eliminated. However, frequent startups may cause impact currents that may greatly reduce the service life of the power supply, subsequent loads, etc., and may even directly cause damage, seriously affecting the stability of the lamps.

[0003] In order to solve the problem of inrush current, most of the current in the market currently adopts the method of connecting a resistor in series in the circuit to reduce the current reaching the subsequent load at the moment of power-on. However, due to the large load power of stage lights, especially the light source module, the series resistor is prone to generate a lot of heat during long-term use, and may burn out, causing the entire circuit to not operate normally. In addition, there is another method of reducing the capacity of the bypass capacitor or decoupling capacitor in the subsequent load circuit. However, due to the large number of modules contained in the lamp, it is difficult to significantly reduce the bypass capacitor and decoupling capacitor, so the protection effect is not obvious.

[0004] Therefore, the existing technology has certain limitations in solving the problems of stage lighting circuit stability and inrush current. The demand for how to start the lighting efficiently and safely has become more urgent, and a protection circuit that can enable the stage lighting to start stably is urgently needed. Summary of the invention

[0005] In order to overcome at least one defect of the above-mentioned prior art, the present invention provides a control circuit with a slow-start switch and a stage light having the same, which solves the problem that the impact current in the control circuit at the moment of power-on causes overload to the subsequent load or switch in the circuit, and utilizes the slow-start function to enable the subsequent load or switch to start smoothly and safely.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a control circuit with a slow-start switch and a stage light with the same, wherein the control circuit with the slow-start switch includes a power supply, a subsequent load and an MCU for outputting a control voltage to start the control circuit, the power supply is a constant voltage power supply, and it is electrically connected to the subsequent load through a delay switch and a current limiting module respectively, and the delay switch is a normally open switch; after the MCU outputs the control voltage, when the power supply is powered on, the current limiting module is turned on first, and when the delay switch is turned on, the current limiting module is automatically disconnected; wherein, the current limiting module transmits a limiting current to the subsequent load. I3 , the surge current of the power supply is I1 , the impact current of the delay switch is I2 , the limiting current I3 Less than or equal to I1 and I2 The minimum value in .

[0007] When the control circuit starts working, the power supply provides a constant voltage, and the current limiting module that is turned on first provides a current limiting module for the subsequent load. I3 , due to the current limit I3 The size is limited to a safe range, effectively suppressing the startup surge current, and the subsequent load can be started safely and smoothly. At this time, the delay switch is set to be delayed from the conduction of the current limiting module. At the same time, when the delay switch is turned on, the current limiting module is automatically disconnected and no longer participates in the power supply. The control circuit is then started, and the power supply continues to supply power to the subsequent load through the delay switch. Compared with the method of directly connecting a resistor in series to the control circuit to reduce the impact current, since the current limiting module only works at the beginning of the start-up and then automatically disconnects, it only works briefly and does not consume additional power at ordinary times, which is conducive to reducing the overall power consumption of the system, and can avoid the situation where the current limiting module generates heat due to long-term operation, thereby optimizing the thermal management of the circuit. At the same time, it also effectively protects the delay switch and the power supply to prevent both from being impacted by the impact current and triggering overload protection, affecting the service life.

[0008] Furthermore, the delay switch includes a second switch K2 connecting the power supply and the subsequent load and a delay control module controlling the second switch K2 to be delayed from being turned on by the current limiting module, the input end of the delay control module is connected to the MCU, and the output end thereof is connected to the second switch K2. When the second switch K2 is turned on, the power supply can continuously supply power to the subsequent load; and through such a setting, the current limiting module and the delay control module can work simultaneously, so as to achieve the purpose of delaying the second switch K2 from being turned on by the current limiting module, thereby improving the safe startup performance of the control circuit and achieving high accuracy.

[0009] Furthermore, the delay control module includes a delay capacitor C1, and when the MCU charges the delay capacitor C1 to a preset voltage, the delay control module controls the second switch K2 to be turned on. The delay effect is achieved by utilizing the characteristics of the capacitor, and the structure is simple and easy to maintain.

[0010] Furthermore, the delay control module also includes a transistor Q4, a field effect transistor Q3, a resistor R6, a resistor R7, a resistor R8, and a resistor R9. The MCU is connected to the positive electrode of the delay capacitor C1 through the resistor R6, the negative electrode of the delay capacitor C1 is connected to the emitter E of the transistor Q4, the resistor R8 connects the positive electrode of the delay capacitor C1 to the base B of the transistor Q4, the resistor R9 connects the base B and the emitter E of the transistor Q4, the collector C of the transistor Q4 is connected to the gate G of the field effect transistor Q3 through the resistor R7, the MCU is connected to the source S of the field effect transistor Q3, and the drain D of the field effect transistor Q3 is connected to the second switch K2. When the delay control module is started, the MCU outputs the voltage VDD to charge the delay capacitor C1. When the delay capacitor C1 reaches the conduction voltage drop value of the transistor Q4, the transistor Q4 is turned on, and the field effect transistor Q3 is also turned on. The voltage VDD output by the MCU flows through the field effect transistor Q3 and is converted into VDD1, thereby closing the second switch K2 and disconnecting the current limiting module, and finally enabling the power supply to continuously supply power to the subsequent load. The delayed time of the delay circuit mainly depends on the delay capacitor C1, and the duration can also be changed by adjusting the resistance values ​​of the resistor R6 and the resistor R8.

[0011] Furthermore, the second switch K2 is a relay or a field effect tube. When the subsequent load requires a larger current value to work, a relay is more suitable; and a field effect tube has better linear characteristics and high stability.

[0012] Furthermore, it also includes a switch K3 for controlling the on and off of the current limiting module. When the delay switch is turned on, the switch K3 disconnects the current limiting module from the MCU for outputting the control voltage, so that the current limiting module disconnects the electrical connection between the power supply and the subsequent load. The use of the switch K3 realizes a smooth transition from the current limiting mode to the normal working mode, prevents the system from generating transient shocks, and controls the on and off of the current limiting module only through the hardware structure logic of the circuit, with a simple structure and high accuracy.

[0013] Furthermore, the switching switch K3 is a relay, the common end of the switching switch K3 is connected to the MCU, the coil end is connected to the delay switch, and the normally closed end is connected to the current limiting module. When the common end of the switching switch K3 receives the control voltage sent by the MCU and the coil end is not started, the switching switch K3 turns on the current limiting module, and the power supply supplies power to the subsequent load to generate the limiting current I3, which has high sensitivity, and the relay contacts can withstand high sudden currents and will not be easily damaged, and have good reliability.

[0014] Furthermore, the current limiting module includes a first switch and a current limiting resistor which are arranged in series between the power supply and the subsequent load. When the delay switch is turned on, the first switch is automatically turned off. The current limiting resistor is used to divide the voltage and reduce the current value, so that the current limiting current I3 output by the current limiting module reaches a safe range value. The circuit structure is simple and easy to implement.

[0015] Furthermore, the current limiting resistor is a thermistor, which has high sensitivity and dynamically changes its resistance value according to the use environment. A positive temperature coefficient thermistor (PTC) or a negative temperature coefficient thermistor (NTC) can be selected according to design requirements.

[0016] Furthermore, the first switch K1 includes a field effect tube connected between the power supply and the subsequent load, and a first control module for controlling the on-off of the field effect tube, and the first control module can be connected to the control voltage on and off. The field effect tube has low power consumption, fast switching speed, no mechanical wear, and can achieve silent operation.

[0017] Further, the first control module includes a transistor Q2, a resistor R2, a resistor R3 and a resistor R4, the source S of the field effect transistor is connected to the power supply, the drain D is connected to the post-stage load gate G is connected to the collector C of the transistor Q2 through the resistor R2, the base B of the transistor Q2 is connected to the MCU for generating a control voltage through the resistor R4, its emitter E is grounded, and the resistor R3 is connected to the base B and emitter E of the transistor Q2. When the base B of the transistor Q2 receives the MCU, the transistor Q2 is turned on and controls the field effect transistor to be turned on, and finally the power supply is used to supply power to the post-stage load. On the contrary, when the connection between the transistor Q2 and the MCU is cut off, that is, the first switch K1 is disconnected, the current limiting module no longer works.

[0018] Furthermore, the first switch K1 is a relay, the coil end of the relay can be connected to the MCU for generating the control voltage, and the on-off switch of the relay is connected to the power supply and the subsequent load respectively. The relay can be directly connected to the MCU without setting up a control module to control its own on-off, further simplifying the circuit structure and having good stability.

[0019] The present invention also provides a stage light, comprising a lamp head for projecting a light beam, and also having any of the control circuits described above, wherein a light source for generating a light beam is installed in the lamp head, and the subsequent load is a driving circuit of the light source. The light source has a large power, so its driving circuit will also generate a large impact current at the moment of startup. By adding the current limiting module, the impact current is effectively reduced, and the safe driving of the light source is further guaranteed.

[0020] Furthermore, it also includes a support arm for pivoting the lamp head and a chassis for pivoting the support arm. The lamp head can rotate relative to the chassis in at least two dimensions, and the post-stage load is a driving circuit for driving the lamp head and / or the support arm to rotate. Vertical scanning is achieved by rotating the lamp head relative to the support arm, and horizontal scanning is achieved by driving the lamp head to rotate relative to the chassis with the support arm. However, since the rotation of the lamp head or the support arm requires a relatively high-power motor, the control circuit needs to be added to prevent the motor from being damaged by the impact of the impact current, so as to ensure the accuracy of the scanning of the stage light.

[0021] Furthermore, it also includes an effect module for intercepting light to produce a specific light effect, and the post-stage load is a driving circuit for driving the effect module. Since the driving circuit of the effect module needs to drive a large number of motors and other electronic components, the driving circuit is effectively protected by connecting to the control circuit, reducing the damage caused by the impact current of these electronic components at the startup moment, effectively ensuring the service life, and making the operation of the effect module more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a principle schematic diagram of a control circuit with a slow-start switch of the present invention.

[0023] Figure 2 It is a circuit structure schematic diagram of the current limiting module when the first switch in the present invention is a field effect tube.

[0024] Figure 3 It is a circuit structure diagram of the second switch in the present invention being a relay delay switch.

[0025] Figure 4 This is a schematic diagram of the circuit structure when the first switch in the present invention is a field effect tube Figure 5 It is a schematic diagram of the circuit structure when the first switch in the present invention is a relay.

[0026] Figure 6 The invention is a schematic diagram of the structure of a stage light equipped with the control circuit with a slow-start switch according to the present invention.

[0027] Figure 7 It is a structural schematic diagram of the support arm of the stage light of the present invention equipped with the control circuit.

[0028] In the figure: 100, control circuit; 110, power supply; 120, post-stage load; 130, current limiting module; 131, current limiting resistor; 132, first control module; 140, delay switch; 141, delay control module; 150, MCU; 160, switching switch K3; 200, lamp holder; 300, support arm; 400, chassis. DETAILED DESCRIPTION

[0029] The drawings are only for illustrative purposes and cannot be construed as limiting the present invention. To better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as limiting the present invention.

[0030] like Figures 1 to 5As shown, a control circuit with a slow-start switch and a stage light with the same, wherein the control circuit with a slow-start switch comprises a power supply 110, a subsequent load 120 and an MCU 150 for outputting a control voltage to start the control circuit 100, wherein the power supply 110 is a constant voltage power supply, and is electrically connected to the subsequent load 120 through a delay switch 140 and a current limiting module 130, respectively, wherein the delay switch 140 is a normally open switch; after the MCU 150 outputs the control voltage, when the power supply 110 is powered on, the current limiting module 130 is first turned on, and when the delay switch 140 is turned on, the current limiting module 130 is automatically turned off; wherein the current limiting module 130 transmits a limiting current I3 to the subsequent load 120, the surge current of the power supply 110 is I1, the surge current of the delay switch 140 is I2, and the limiting current I3 is less than or equal to the minimum value of I1 and I2.

[0031] When the control circuit 100 starts to work, the power supply 110 provides a constant voltage, and the current limiting module 130 that is turned on first is set to provide the current limiting I3 for the subsequent load 120. Since the size of the current limiting I3 is limited within a safe range, the startup surge current is effectively suppressed, and the subsequent load 120 can be safely and smoothly started. At this time, the delay switch 140 is set to be delayed from the current limiting module 130. At the same time, when the delay switch 140 is turned on, the current limiting module 130 is automatically disconnected and no longer participates in power supply. The control circuit 100 is started, and the power supply 110 continuously supplies power to the subsequent load 120 through the delay switch 140. Compared with the method of directly connecting a resistor in series to the control circuit 100 to reduce the impact current, since the current limiting module 130 only works at the beginning of the start-up, and then automatically disconnects, it only works briefly and does not consume additional power at ordinary times, which is conducive to reducing the overall power consumption of the system, and can avoid the situation where the current limiting module 130 generates heat due to long-term operation, and optimizes the thermal management of the circuit. At the same time, the delay switch 140 and the power supply 110 are effectively protected to prevent the two from being impacted by the impact current and triggering the overload protection, thereby affecting the service life.

[0032] Preferably, the MCU150 is a control switch for the current limiting module 130 and the delay switch 140, that is, when the MCU150 sends out a control voltage, the current limiting module 130 and the delay switch 140 can be turned on and work, and when the MCU150 stops sending out the control voltage or sends a stop signal, the above two modules cannot be started.

[0033] Preferably, the control voltage VDD issued by the MCU 150 is 5V.

[0034] Preferably, the limiting current I3 is smaller than the minimum value between I1 and I2.

[0035] In a preferred embodiment of the present invention, the delay switch 140 includes a second switch K2 connecting the power supply 110 and the subsequent load 120 and a delay control module 141 for controlling the second switch K2 to be delayed from being turned on by the current limiting module 130. The input end of the delay control module 141 is connected to the MCU 150, and the output end thereof is connected to the second switch K2. When the second switch K2 is turned on, the power supply 110 can continuously supply power to the subsequent load 120; and through such a setting, the current limiting module 130 and the delay control module 141 can work simultaneously, so as to achieve the purpose of delaying the second switch K2 from being turned on by the current limiting module 130, thereby improving the safe startup performance of the control circuit 100 and achieving high accuracy.

[0036] In a preferred embodiment of the present invention, the delay control module 141 includes a delay capacitor C1. When the MCU 150 charges the delay capacitor C1 to a preset voltage, the delay control module 141 controls the second switch K2 to be turned on. The delay effect is achieved by utilizing the characteristics of the capacitor, and the structure is simple and easy to maintain.

[0037] In a preferred embodiment of the present invention, the delay control module 141 also includes a transistor Q4, a field effect transistor Q3, a resistor R6, a resistor R7, a resistor R8, and a resistor R9. The MCU150 is connected to the positive electrode of the delay capacitor C1 through the resistor R6, the negative electrode of the delay capacitor C1 is connected to the emitter E of the transistor Q4, the resistor R8 connects the positive electrode of the delay capacitor C1 to the base B of the transistor Q4, the resistor R9 connects the base B and the emitter E of the transistor Q4, the collector C of the transistor Q4 is connected to the gate G of the field effect transistor Q3 through the resistor R7, the MCU150 is connected to the source S of the field effect transistor Q3, and the drain D of the field effect transistor Q3 is connected to the second switch K2. When the delay control module 141 is started, the MCU150 outputs a voltage VDD to charge the delay capacitor C1. When the delay capacitor C1 reaches the conduction voltage drop value of the transistor Q4, the transistor Q4 is turned on, and the field effect transistor Q3 is also turned on. The voltage VDD output by the MCU150 flows through the field effect transistor Q3 and is converted into VDD1, thereby closing the second switch K2 and disconnecting the current limiting module 130, and finally enabling the power supply 110 to continuously supply power to the subsequent load 120. The delayed time of the delay circuit mainly depends on the delay capacitor C1, and the duration can also be changed by adjusting the resistance values ​​of the resistor R6 and the resistor R8.

[0038] Preferably, a limiting resistor R5 is further included, and the limiting resistor R5 is respectively connected to the source S and the gate G of the field effect transistor Q3.

[0039] Preferably, it also includes a switching switch K3160 for controlling the on and off of the current limiting module 130. The switching switch K3160 is a relay. When the delay switch 140 is turned on, the switching switch K3160 cuts off the MCU150 of the current limiting module 130, so that the current limiting module 130 disconnects the connection between the power supply 110 and the subsequent load 120.

[0040] Preferably, MCU150 is VDD, the on-state voltage drop of transistor Q4 is Vbe (when transistor Q4 is replaced by MOS tube, its on-state voltage drop is Vgs), and the on-state current of transistor Q4 is I4=(VDD-Vbe) / (R6+R8); therefore, the charging current of the delay capacitor C1 is I4, and the time required for the delay capacitor C1 to reach the on-state voltage drop value Vbe of the transistor Q4 is: t1=-R*C1*Ln(1-Vbe / VDD). Wherein, R is the sum of the resistance values ​​of the resistor R6 and the resistor R8, and C1 is the capacitance value of the delay capacitor C1. That is, the delay time of the delay switch 140 to the on-state of the current limiting module 130 is greater than or equal to t1.

[0041] Optionally, the appropriate delay time length may be set by adjusting the resistance value of the resistor R6 or the resistor R8 or the capacitance of the delay capacitor C1.

[0042] Optionally, the transistor Q4 can be replaced by a MOS tube, and the delay capacitor C1 and the field effect tube Q3 are also used to delay the conduction of the second switch K2, and other circuit structures in the delay control module 141 are adaptively adjusted.

[0043] In a preferred embodiment of the present invention, the second switch K2 is a relay or a field effect tube. When the subsequent load 120 requires a larger current value to work, a relay is more suitable; and a field effect tube has better linear characteristics and high stability.

[0044] Preferably, when the second switch K2 is a relay, a protection diode D1 is connected in parallel to the coil end of the second switch K2.

[0045] In a preferred embodiment of the present invention, a switch K3160 for controlling the on / off of the current limiting module 130 is further included. When the delay switch 140 is turned on, the switch K3160 disconnects the current limiting module 130 from the MCU 150 for outputting the control voltage, so that the current limiting module 130 disconnects the electrical connection between the power supply 110 and the subsequent load 120. The use of the switch K3160 realizes a smooth transition from the current limiting mode to the normal working mode, prevents the system from generating transient shocks, and controls the on / off of the current limiting module 130 only through the hardware structure logic of the circuit, with a simple structure and high accuracy.

[0046] In a preferred embodiment of the present invention, the switching switch K3160 is a relay, the common end of the switching switch K3160 is connected to the MCU150, the coil end is connected to the delay switch 140, and the normally closed end is connected to the current limiting module 130. When the common end of the switching switch K3160 receives the control voltage sent by the MCU150 and the coil end is not started, the switching switch K3160 turns on the current limiting module 130, and the power supply 110 supplies power to the subsequent load 120 to generate the limiting current I3, with high sensitivity, and the relay contacts can withstand high sudden currents and will not be easily damaged, and have good reliability.

[0047] Preferably, the coil end of the switching switch K3160 is pin 1, the normally closed end is pin 2, and the common end is pin 3.

[0048] Preferably, the delay switch 140 includes a field effect transistor Q3 and a second switch K2. The MCU150VDD is converted into VDD1 through the field effect transistor Q3. The converted MCU150VDD1 turns on the second switch K2 (that is, it is regarded as the delay switch 140 being turned on). At the same time, the field effect transistor Q3 inputs the converted MCU150VDD1 to the coil end (pin 1) of the switching switch K3160, so that the normally closed end is disconnected, and finally the current limiting module 130 stops working.

[0049] In a preferred embodiment of the present invention, the current limiting module 130 includes a first switch and a current limiting resistor 131 which are arranged in series between the power supply 110 and the subsequent load 120. When the delay switch 140 is turned on, the first switch is automatically turned off. The current limiting resistor 131 is used to divide the voltage and reduce the current value, so that the current limiting I3 output by the current limiting module 130 reaches a safe range value. The circuit structure is simple and easy to implement.

[0050] In a preferred embodiment of the present invention, the current limiting resistor 131 is a thermistor, which has high sensitivity and dynamically changes its resistance value according to the use environment. A positive temperature coefficient thermistor (PTC) or a negative temperature coefficient thermistor (NTC) can be selected according to design requirements.

[0051] Preferably, the current limiting resistor 131 is a negative temperature coefficient thermistor (NTC), and its resistance value decreases as the temperature increases. During the operation of the current limiting module 130, a large resistance value will not be generated due to excessive temperature, so that the current gradually increases, which is conducive to the smooth startup of the control circuit 100.

[0052] In a preferred embodiment of the present invention, the first switch K1 includes a field effect tube connected between the power supply 110 and the subsequent load 120, and a first control module 132 for controlling the on-off of the field effect tube, and the first control module 132 can be connected to the control voltage on and off. The field effect tube has low power consumption, fast switching speed, no mechanical wear, and can achieve silent operation.

[0053] Preferably, it further includes a switch K3160 for controlling the on and off of the current limiting module 130 , and the first control module 132 is electrically connected to the normally closed end of the switch K3160 .

[0054] In a preferred embodiment of the present invention, the first control module 132 includes a transistor Q2, a resistor R2, a resistor R3 and a resistor R4, the source S of the field effect transistor is connected to the power supply 110, the drain D is connected to the post-stage load 120, the gate G is connected to the collector C of the transistor Q2 through the resistor R2, the base B of the transistor Q2 is connected to the MCU 150 for generating a control voltage through the resistor R4, and its emitter E is grounded, and the resistor R3 is connected to the base B and the emitter E of the transistor Q2. When the base B of the transistor Q2 receives the MCU 150, the transistor Q2 is turned on and controls the field effect transistor to be turned on, and finally the power supply 110 supplies power to the post-stage load 120. On the contrary, when the connection between the transistor Q2 and the MCU 150 is cut off, that is, the first switch K1 is disconnected, the current limiting module 130 no longer works.

[0055] Preferably, a limiting resistor R1 is further included, and the limiting resistor R1 is respectively connected to the source S and the drain D of the field effect tube.

[0056] Optionally, the transistor Q2 can be replaced by a MOS transistor.

[0057] In a preferred embodiment of the present invention, the first switch K1 is a relay, the coil end of the relay can be connected to the MCU 150 for generating a control voltage, and the on-off switch of the relay is respectively connected to the power supply 110 and the subsequent load 120. The relay can be directly connected to the MCU 150 without setting up a control module to control its own on-off, further simplifying the circuit structure and having good stability.

[0058] like Figure 1 , Figure 6 and Figure 7 As shown, the present invention also provides a stage light, including a lamp head 200 for projecting a light beam, and any of the control circuits 100 described above, wherein a light source for generating a light beam is installed in the lamp head 200, and the post-stage load 120 is a driving circuit of the light source. The light source has a large power, so its driving circuit will also generate a large impact current at the moment of startup. By adding the current limiting module 130, the impact current is effectively reduced, and the safe driving of the light source is further guaranteed.

[0059] In a preferred embodiment of the present invention, a support arm 300 for pivoting the lamp head 200 and a chassis 400 for pivoting the support arm 300 are also included. The lamp head 200 can rotate relative to the chassis 400 around at least two dimensions, and the post-stage load 120 is a driving circuit for driving the lamp head 200 and / or the support arm 300 to rotate. Vertical scanning is achieved by rotating the lamp head 200 relative to the support arm 300, and horizontal scanning is achieved by driving the lamp head 200 relative to the chassis 400 with the support arm 300. However, since the rotation of the lamp head 200 or the support arm 300 requires a motor with relatively high power, the control circuit 100 needs to be added to prevent the motor from being damaged by the impact of the impact current, so as to ensure the accuracy of the scanning of the stage light.

[0060] Preferably, the power supply 110 is installed inside the support arm 300 or inside the chassis 400 .

[0061] In a preferred embodiment of the present invention, an effect module for intercepting light to produce a specific light effect is also included, and the post-stage load 120 is a driving circuit for driving the effect module. Since the driving circuit of the effect module needs to drive a large number of motors and other electronic components, the driving circuit is effectively protected by connecting to the control circuit 100, reducing the damage caused by the impact current of these electronic components at the startup moment, effectively ensuring the service life, and making the operation of the effect module more accurate.

[0062] Preferably, the working time of the current limiting module 130 is very short, almost within 1s or even a few milliseconds. After completing the slow start, it switches to the normal power supply mode, and the audience can hardly notice the delay in the light effect of the stage light; each of the driving circuits can effectively cope with frequent and multiple starts, ensuring the stable operation of the stage light.

[0063] For example, when the operating current provided by the power supply 110 to the subsequent load 120 is 100A, the limiting current I3 output by the limiting current module 130 is 5A.

[0064] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A control circuit with a slow-start switch, characterized in that: The invention comprises a power supply (110), a subsequent load (120) and an MCU (150) for outputting a control voltage for starting the control circuit (100); the power supply (110) is a constant voltage power supply, and is electrically connected to the subsequent load (120) through a delay switch (140) and a current limiting module (130), respectively; the delay switch (140) is a normally open switch; after the MCU (150) outputs the control voltage, when the power supply (110) is powered on, the current limiting module (130) is first turned on, and when the delay switch (140) is turned on, the current limiting module (130) is automatically turned off; wherein the current limiting module (130) transmits a limiting current I3 to the subsequent load (120); the anti-shock current of the power supply (110) is I1, the anti-shock current of the delay switch (140) is I2, and the limiting current I3 is less than or equal to the minimum value of I1 and I2.

2. The control circuit according to claim 1, characterized in that: The delay switch (140) comprises a second switch K2 connecting the power supply (110) and the subsequent load (120), and a delay control module (141) controlling the second switch K2 to be turned on later than the current limiting module (130), wherein the input end of the delay control module (141) is connected to the MCU (150), and the output end thereof is connected to the second switch K2.

3. The control circuit according to claim 2, characterized in that: The delay control module (141) comprises a delay capacitor C1. When the MCU (150) charges the delay capacitor C1 to a preset voltage, the delay control module (141) controls the second switch K2 to be turned on.

4. The control circuit according to claim 3, characterized in that: The delay control module (141) further comprises a transistor Q4, a field effect transistor Q3, a resistor R6, a resistor R7, a resistor R8 and a resistor R9; the MCU (150) is connected to the positive electrode of the delay capacitor C1 via the resistor R6; the negative electrode of the delay capacitor C1 is connected to the emitter E of the transistor Q4; the resistor R8 is connected to the positive electrode of the delay capacitor C1 and the base B of the transistor Q4; the resistor R9 is connected to the base B and the emitter E of the transistor Q4; the collector C of the transistor Q4 is connected to the gate G of the field effect transistor Q3 via the resistor R7; the MCU (150) is connected to the source S of the field effect transistor Q3; and the drain D of the field effect transistor Q3 is connected to the second switch K2.

5. The control circuit according to claim 2, characterized in that: The second switch K2 is a relay or a field effect transistor.

6. The control circuit according to claim 1, characterized in that: It also includes a switching switch K3 (160) for controlling the on and off of the current limiting module (130); when the delay switch (140) is turned on, the switching switch K3 (160) disconnects the current limiting module (130) from the MCU (150) for outputting a control voltage, so that the current limiting module (130) disconnects the electrical connection between the power supply (110) and the subsequent load (120).

7. The control circuit according to claim 6, characterized in that: The switching switch K3 (160) is a relay, the common end of the switching switch K3 (160) is connected to the MCU (150), the coil end is connected to the delay switch (140), and the normally closed end is connected to the current limiting module (130).

8. The control circuit according to claim 1, characterized in that: The current limiting module (130) comprises a first switch K1 and a current limiting resistor (131) which are arranged in series between the power supply (110) and the subsequent load (120); when the delay switch (140) is turned on, the first switch K1 is automatically turned off.

9. The control circuit according to claim 8, characterized in that: The current limiting resistor (131) is a thermistor.

10. The control circuit according to claim 8, characterized in that: The first switch K1 comprises a field effect tube connected between the power supply (110) and the subsequent load (120), and a first control module (132) for controlling the on-off of the field effect tube, wherein the first control module (132) can be connected to a control voltage in an on-off manner.

11. The control circuit according to claim 10, characterized in that: The first control module (132) comprises a transistor Q2, a resistor R2, a resistor R3 and a resistor R4; the source S of the field effect transistor is connected to the power supply (110); the drain D is connected to the post-stage load (120); the gate G is connected to the collector C of the transistor Q2 through the resistor R2; the base B of the transistor Q2 is connected to the MCU (150) for generating a control voltage through the resistor R4 in a switchable manner; the emitter E is grounded; and the resistor R3 is connected to the base B and the emitter E of the transistor Q2.

12. The control circuit according to claim 8, characterized in that: The first switch K1 is a relay, the coil end of which can be connected to an MCU (150) for generating a control voltage in an on-off manner, and the on-off switch of the relay is respectively connected to the power supply (110) and the subsequent load (120).

13. A stage light, comprising a lamp head (200) for projecting a light beam, and a control circuit (100) as claimed in any one of claims 1 to 12, wherein a light source for generating a light beam is installed in the lamp head (200), and the subsequent load (120) is a driving circuit for the light source.

14. The stage light according to claim 13, characterized in that: It also includes a support arm (300) for pivotally connecting the lamp head (200) and a chassis (400) for pivotally connecting the support arm (300); the lamp head (200) can rotate around at least two dimensions relative to the chassis (400); and the post-stage load (120) is a driving circuit for driving the lamp head (200) and / or the support arm (300) to rotate.

15. The stage light according to claim 13, characterized in that: It also includes an effect module for intercepting light to produce a specific light effect, and the post-stage load (120) is a driving circuit for driving the effect module.

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