An LED control circuit

Abstract

This invention discloses an LED control circuit, comprising: a switch module for connecting to a power supply module; and a controlled switch module connected to the switch module for connecting to an LED module, and further configured to control the positive terminal of the LED module to connect to the positive terminal of the power supply module and the negative terminal of the LED module to connect to the negative terminal of the power supply module when the switch module is turned on, and to control the positive terminal of the LED module to connect to the negative terminal of the power supply module and the negative terminal of the LED module to connect to the positive terminal of the power supply module when the switch module is turned off.

Description

Technical Field

[0001] This disclosure relates to the field of LED lamp turn-off circuit technology, and in particular to an LED control circuit. Background Technology

[0002] Conventional LED frequency-free flash circuits mainly use a disconnect circuit design. The disconnect circuit design may cause the LED to flicker slightly when it is turned off for the following reasons: due to differences in LED VF value, incomplete disconnection of the power supply circuit (switch connected to the neutral wire), or the influence of floating ground, etc.

[0003] To avoid the problem of LEDs flickering when they are off, current solutions require complex circuit designs, which are costly. Summary of the Invention

[0004] This disclosure provides an LED control circuit to solve the above-mentioned technical problems.

[0005] This disclosure provides an LED control circuit, including: a switch module for connecting to a power supply module; and a controlled switch module connected to the switch module for connecting to an LED module, and further configured to control the positive terminal of the LED module to connect to the positive terminal of the power supply module and the negative terminal of the LED module to connect to the negative terminal of the power supply module when the switch module is turned on, and to control the positive terminal of the LED module to connect to the negative terminal of the power supply module and the negative terminal of the LED module to connect to the positive terminal of the power supply module when the switch module is turned off.

[0006] Preferably, the manual switch module is a double-pole double-throw relay K1, which includes: Two coil pins, each of which is connected to the switch module; The first common terminal pin is used to connect to the positive terminal of the LED module; The second common terminal pin is used to connect to the negative terminal of the LED module; The first normally open pin is used to connect to the negative terminal of the power supply module; The first normally closed pin is used to connect to the positive terminal of the power module; The second normally open pin is used to connect to the positive terminal of the power module; The second normally closed pin is used to connect to the negative terminal of the power supply module.

[0007] Preferably, the switching module includes a transistor Q1, a capacitor C1, and resistors R2, R3, and R4. The collector of transistor Q1 is connected to one end of resistor R4, and the other end of resistor R4 is connected to the positive terminal of the power supply module. The emitter of transistor Q1 is connected to one of the coil pins, and the base of transistor Q1 is connected to the other coil pin. The base of transistor Q1 is connected to capacitor C1, resistors R2 and R3. Capacitor C1 and resistor R3 are connected to the negative terminal of the power supply module, and resistor R2 is connected to the positive terminal of the power supply module.

[0008] Preferably, the switching module further includes a diode ZD1, which is connected in series between the base of the transistor Q1 and the coil pin.

[0009] Preferably, the LED control circuit further includes the power supply module.

[0010] Preferably, the power supply module includes a DC power supply, the positive terminal of which is connected to the collector, the first normally closed terminal, and the second normally open terminal of the transistor Q1, respectively, and the negative terminal of which is connected to the base, the first normally open terminal pin, and the second normally closed terminal of the transistor Q1, respectively.

[0011] Preferably, the power module further includes a capacitor CE1, the two ends of which are connected to the positive and negative terminals of the DC power supply, respectively.

[0012] Preferably, the power module further includes a resistor R1, which is connected in parallel with the capacitor CE1.

[0013] Preferably, the power module further includes a diode D1, which is connected in series between the positive terminal of the DC power supply and the capacitor CE1.

[0014] Preferably, the LED control circuit further includes the LED module, and the LED module further includes a capacitor C3 and a resistor R5, wherein the capacitor C3 is connected in parallel with the LED module, and the resistor R5 is connected in parallel with the LED module.

[0015] The main advantages of this disclosure are: the present invention filters the input DC voltage through the power supply module and then transmits it to the intermediate switch module. The switch module drives the relay of the controlled switch module to work. When the power is turned off, the controlled switch module switches the voltage direction of the overall circuit, so that the voltage across the LED module becomes reversed, causing the LED of the LED module to turn off quickly and eliminating the flickering. In addition, the circuit design is simple and the cost is low.

[0016] It should be understood that both the foregoing general description and the following detailed description are for illustrative purposes and do not necessarily limit the scope of this disclosure. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the subject matter of this disclosure. Furthermore, the specification and drawings serve to explain the principles of this disclosure. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a circuit diagram of an LED control system according to an embodiment of the present disclosure; Icons: 100 - Power module; 200 - Switch module; 300 - Controlled switch module; 400 - LED module. Detailed Implementation

[0019] The technical solutions of this disclosure will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments.

[0020] Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0021] In the description of this disclosure, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0022] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0023] Example like Figure 1 As shown, this embodiment provides an LED control circuit, including: a switch module 200 for connecting to a power supply module 100; and a controlled switch module 300 connected to the switch module 200 for connecting to an LED module 400, and further configured to control the positive terminal of the LED module 400 to connect to the positive terminal of the power supply module 100 and the negative terminal of the LED module 400 to connect to the negative terminal of the power supply module 100 when the switch module 200 is turned on, and to control the positive terminal of the LED module 400 to connect to the negative terminal of the power supply module 100 and the negative terminal of the LED module 400 to connect to the positive terminal of the power supply module 100 when the switch module 200 is turned off. In this embodiment, the power module 100 provides DC power. When the power module 100 provides current, the switch module 200 controls the controlled switch module 300 to connect the positive terminal of the LED module 400 to the positive terminal of the power module 100 and the negative terminal of the LED module 400 to the negative terminal of the power module 100. At this time, the LED module 400 works normally. When the power module 100 is de-energized, the switch module 200 controls the controlled switch module 300 to change the connection direction between the LED module 400 and the power module 100, connecting the positive terminal of the LED module 400 to the negative terminal of the power module 100 and the negative terminal of the LED module 400 to the positive terminal of the power module 100. At this time, because the voltage direction of the LED module 400 is reversed, the LED of the LED module 400 is quickly extinguished, eliminating the occurrence of flickering. Moreover, the circuit design is simple and the cost is low.

[0024] In one specific embodiment, the manual switch module 200 is a double-pole double-throw relay K1, which includes: two coil pins, a first common terminal pin, a second common terminal pin, a first normally open terminal pin, a first normally closed terminal pin, a second normally open terminal pin, and a second normally closed terminal pin; the two coil pins are respectively connected to the switch module 200; the first common terminal pin is used to connect to the positive terminal of the LED module 400; the second common terminal pin is used to connect to the negative terminal of the LED module 400; the first normally open terminal pin is used to connect to the negative terminal of the power module 100; the first normally closed terminal pin is used to connect to the positive terminal of the power module 100; the second normally open terminal pin is used to connect to the positive terminal of the power module 100; and the second normally closed terminal pin is used to connect to the negative terminal of the power module 100. In this embodiment, a double-pole double-throw relay K1 is used as the controlled switch module 300. The switch module 200 is connected to two coil pins to control the normally open / normally closed state of the relay, thereby switching the positive and negative connection relationship between the LED module 400 and the power module 100, so as to quickly switch the polarity connection relationship between the LED module 400 and the power module 100, thereby realizing the rapid turn-on and turn-off of the LED module 400.

[0025] It should be noted that although this embodiment uses a double-pole double-throw relay K1 as the controlled switch, this is only one possible embodiment. All controlled switches in the prior art that can achieve rapid switching of voltage direction should be included in the protection scope of this application.

[0026] In one specific embodiment, the switching module 200 includes a transistor Q1, a capacitor C1, and resistors R2, R3, and R4. The collector of transistor Q1 is connected to one end of resistor R4, and the other end of resistor R4 is connected to the positive terminal of the power supply module 100. The emitter of transistor Q1 is connected to one of the coil pins, and the base of transistor Q1 is connected to the other coil pin. The base of transistor Q1 is connected to capacitor C1, resistors R2 and R3. Capacitor C1 and resistor R3 are connected to the negative terminal of the power supply module 100, and resistor R2 is connected to the positive terminal of the power supply module 100. In this embodiment, when the power supply module 100 supplies power, transistor Q1 supplies power to the relay coil through resistor R4 with current limiting. Since the resistance value of resistor R2 on the base of transistor Q1 is less than the resistance value of resistor R3, the circuit is turned on at this time. When the circuit is closed, the capacitance of capacitor CE1 is greater than that of capacitor C1. At this time, because the forward voltage of resistor R2 decreases and becomes less than that of resistor R3, transistor Q1 is cut off, and the subsequent controlled switch module 300 loses voltage. At this time, the relay is in the normally open state, the voltage direction of LED module 400 is reversed, and LED module 400 is quickly turned off without flickering.

[0027] Furthermore, the switching module 200 also includes a diode ZD1, which is connected in series between the base of transistor Q1 and the coil pin. Diode ZD1 is a Zener diode, providing a threshold reference voltage. When the voltage divider exceeds its regulated value, it breaks down and conducts, triggering transistor Q1 to conduct, thus enabling the relay to operate when the voltage reaches the threshold.

[0028] In one specific embodiment, the LED control circuit further includes the power supply module 100. The power supply module 100 is used to provide power for the operation of subsequent circuits.

[0029] In one specific embodiment, the power supply module 100 includes a DC power supply. The positive terminal of the DC power supply is connected to the collector, the first normally closed terminal, and the second normally open terminal of transistor Q1, respectively. The negative terminal of the DC power supply is connected to the base, the first normally open terminal pin, and the second normally closed terminal of transistor Q1, respectively. In this embodiment, the DC power supply provides power to transistor Q1, double-pole double-throw relay K1, and LED module 400. When the DC power supply provides current, transistor Q1 supplies power to the relay coil through resistor R4 with current limiting. Since the resistance R2 on the base of transistor Q1 is less than the resistance R3, the circuit is conducting. When the DC power supply is turned off, the capacitance of capacitor CE1 is greater than the capacitance of capacitor C1. At this time, because the forward voltage of resistor R2 decreases and becomes less than that of resistor R3, transistor Q1 is cut off, and the subsequent controlled switch module 300 loses voltage. At this time, the relay is in the normally open state, the voltage direction of LED module 400 is reversed, and LED module 400 quickly turns off without flickering.

[0030] In one specific embodiment, the power module 100 further includes a capacitor CE1, the two ends of which are connected to the positive and negative terminals of the DC power supply, respectively. The capacitor CE1 is used for filtering and storing energy during power input, smoothing the ripple of the DC power supply output, and providing instantaneous current during load switching to suppress voltage fluctuations.

[0031] In one specific embodiment, the power module 100 further includes a resistor R1, which is connected in parallel with the capacitor CE1. Since the capacitance stored in the capacitor CE1 is discharged through the resistor R1, the reverse voltage experienced by the LED module 400 will decrease rapidly, preventing damage to the LED module 400 caused by prolonged reverse voltage.

[0032] In one specific embodiment, the power module 100 further includes a diode D1, which is connected in series between the positive terminal of the DC power supply and the capacitor CE1. The diode D1 serves as reverse connection protection, preventing damage to the circuit when the input power supply polarity is reversed.

[0033] In one specific embodiment, the LED control circuit further includes an LED module 400. The LED module 400 also includes a capacitor C3 and a resistor R5. The capacitor C3 and resistor R5 are connected in parallel with the LED module 400. In this embodiment, the LED module 400 is the load of the circuit output and can be composed of a single LED or multiple LEDs connected in series. The capacitor C3 filters the switched main circuit voltage, further smoothing the voltage ripple and improving the stability of the output voltage. The resistor R5 limits the current in the branch of the LED module 400 to prevent the LED module 400 from burning out due to overcurrent.

[0034] The working principle of this invention: When the power supply circuit is working, capacitor CE1 is charged and the circuit is filtered and stored. Transistor Q1 supplies power to the coil of double-pole double-throw relay K1 through the circuit with resistor R4 for current limiting. Since the resistance value of resistor R2 on the base of transistor Q1 is less than that of resistor R3, the circuit is turned on at this time. During normal operation, the double-pole double-throw relay K1 coil is energized due to the circuit conduction. At this time, the contact K1a, which was originally connected to the negative terminal, turns to the positive terminal, and K1b, which was connected to the positive terminal, turns to the negative terminal. The overall polarity of the circuit is reversed, and the LED module 400 starts to work. When the circuit is closed, the capacitance of capacitor CE1 is greater than that of capacitor C1. The operating mode of switch module 200 is as follows: because the forward voltage of resistor R2 decreases to less than that of grounded resistor R3, transistor Q1 is cut off. The coil of double-pole double-throw relay K1 loses voltage, and contact K1a changes from positive to negative, and contact K1b changes from negative to positive. Due to the reverse voltage, LED module 400 quickly turns off. Furthermore, because the capacitance stored in capacitor CE1 is discharged through resistor R1, the reverse voltage on LED module 400 will decrease rapidly, preventing damage caused by prolonged reverse voltage.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure.

Claims

1. An LED control circuit, characterized in that, include: The switch module is used to connect to the power supply module; A controlled switch module is connected to the switch module for connecting an LED module. It is also used to control the positive terminal of the LED module to connect to the positive terminal of the power module and the negative terminal of the LED module to connect to the negative terminal of the power module when the switch module is turned on, and to control the positive terminal of the LED module to connect to the negative terminal of the power module and the negative terminal of the LED module to connect to the positive terminal of the power module when the switch module is turned off.

2. The LED control circuit according to claim 1, characterized in that, The manual switch module is a double-pole double-throw relay K1, which includes: Two coil pins, each of which is connected to the switch module; The first common terminal pin is used to connect to the positive terminal of the LED module; The second common terminal pin is used to connect to the negative terminal of the LED module; The first normally open pin is used to connect to the negative terminal of the power supply module; The first normally closed pin is used to connect to the positive terminal of the power supply module; The second normally open pin is used to connect to the positive terminal of the power module; The second normally closed pin is used to connect to the negative terminal of the power supply module.

3. The LED control circuit according to claim 2, characterized in that, The switching module includes a transistor Q1, a capacitor C1, and resistors R2, R3, and R4. The collector of transistor Q1 is connected to one end of resistor R4, and the other end of resistor R4 is connected to the positive terminal of the power supply module. The emitter of transistor Q1 is connected to one of the coil pins, and the base of transistor Q1 is connected to the other coil pin. The base of transistor Q1 is connected to capacitor C1, resistors R2 and R3. Capacitor C1 and resistor R3 are connected to the negative terminal of the power supply module, and resistor R2 is connected to the positive terminal of the power supply module.

4. The LED control circuit according to claim 3, characterized in that, The switching module also includes a diode ZD1, which is connected in series between the base of the transistor Q1 and the coil pin.

5. The LED control circuit according to claim 3, characterized in that, The LED control circuit also includes the power supply module.

6. The LED control circuit according to claim 5, characterized in that, The power supply module includes a DC power supply. The positive terminal of the DC power supply is connected to the collector, the first normally closed terminal, and the second normally open terminal of the transistor Q1, respectively. The negative terminal of the DC power supply is connected to the base, the first normally open terminal pin, and the second normally closed terminal of the transistor Q1, respectively.

7. An LED control circuit according to claim 6, characterized in that, The power module also includes a capacitor CE1, the two ends of which are connected to the positive and negative terminals of the DC power supply, respectively.

8. The LED control circuit according to claim 7, characterized in that, The power module also includes a resistor R1, which is connected in parallel with the capacitor CE1.

9. An LED control circuit according to claim 8, characterized in that, The power module also includes a diode D1, which is connected in series between the positive terminal of the DC power supply and the capacitor CE1.

10. An LED control circuit according to claim 1, characterized in that, The LED control circuit also includes the LED module, which further includes a capacitor C3 and a resistor R5. The capacitor C3 and the resistor R5 are connected in parallel with the LED module.

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