LED drive circuit compatible with neon bulb switch

Abstract

The utility model provides an LED drive circuit compatible with a neon bulb switch. The LED drive circuit comprises a neon lamp switch unit, a rectification unit, a drive unit and a neon lamp communication unit. The input end of the neon lamp switch unit is used for being connected with a live wire, the output end of the neon lamp switch unit is connected with the first input end of the rectification unit, and the second input end of the rectification unit is used for being connected with a zero wire. The first output end of the rectification unit is connected with the power input end of the driving unit and the input end of the neon lamp connection unit. The second output end of the rectification unit is connected with the output end of the neon lamp connection unit and is grounded. According to the LED driving circuit compatible with the neon bulb switch, the neon lamp connection unit is arranged behind the rectification unit, so that when the neon bulb switch is turned off, the neon lamp connection unit can provide a current loop for the neon lamp switch unit, namely, the neon lamp connection unit replaces an existing safety capacitor in front of a bridge, and therefore, the size of the LED driving circuit compatible with the neon bulb switch is reduced, and the cost is reduced; and the cost performance of the product is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to an LED drive circuit compatible with a neon bulb switch. Background Art

[0002] At present, most of the control switches of LED lighting have neon bulb indication function. That is, when the control switch is disconnected, the driving circuit will connect to the neon bulb to play the role of indication in the dark.

[0003] In order to be compatible with neon bulb control switches, LED lighting drive circuits need to provide a current loop for neon bulb operation. Most current LED lighting drive circuits use a design that uses safety capacitors (including X capacitors and Y capacitors) in parallel before the bridge. However, X capacitors are not only large in size but also expensive, which is not conducive to the miniaturization of LED lighting products. This also results in LED lighting products that are compatible with neon bulb switches having a lower cost-performance ratio than other types of LED lighting products. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide an LED driving circuit compatible with a neon bulb switch, reduce the volume of the LED driving circuit compatible with the neon bulb switch, and improve the product cost performance.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A neon bulb switch-compatible LED driving circuit comprises a neon lamp switch unit, a rectifier unit, a drive unit and a neon lamp connection unit; the input end of the neon lamp switch unit is used to be connected to a live wire, the output end of the neon lamp switch unit is connected to a first input end of the rectifier unit, and the second input end of the rectifier unit is used to be connected to a neutral wire; the first output end of the rectifier unit is respectively connected to a power input end of the drive unit and an input end of the neon lamp connection unit; the second output end of the rectifier unit is connected to an output end of the neon lamp connection unit and is grounded.

[0007] Furthermore, it also includes a first resistor, and the neon lamp connection unit includes a second resistor; one end of the first resistor is connected to the first output end of the rectifier unit; the other end of the first resistor is respectively connected to the power input end of the drive unit and one end of the second resistor; the other end of the second resistor is grounded.

[0008] Furthermore, the driving unit includes a driving chip, a diode, an inductor, a first capacitor and a third resistor; the power input end of the driving chip is respectively connected to the other end of the first resistor and one end of the second resistor; the output end of the driving chip is respectively connected to the positive electrode of the diode and one end of the inductor; the negative electrode of the diode is respectively connected to one end of the first resistor, one end of the first capacitor and one end of the third resistor; the other end of the inductor is respectively connected to the other end of the first capacitor and the other end of the third resistor; the two ends of the first capacitor are used to power the LED light source.

[0009] Furthermore, the driving unit further includes a fourth resistor; one end of the fourth resistor is connected to the overvoltage protection end of the driving chip, and the other end of the fourth resistor is connected to the second output end of the rectifying unit.

[0010] Furthermore, the driving unit further includes a fifth resistor; one end of the fifth resistor is connected to the over-temperature protection end of the driving chip, and the other end of the fifth resistor is connected to the second output end of the rectifying unit.

[0011] Furthermore, the driving unit further includes a sixth resistor; one end of the sixth resistor is connected to the current control end of the driving chip, and the other end of the sixth resistor is connected to the second output end of the rectifying unit.

[0012] Furthermore, the rectifier unit includes a rectifier bridge stack and a second capacitor; the first input end of the rectifier bridge stack is connected to the output end of the neon lamp switch unit; the second input end of the rectifier bridge stack is used to connect to the neutral line; the first output end of the rectifier bridge stack is respectively connected to the power input end of the drive unit, the input end of the neon lamp connection unit and one end of the second capacitor; the second output end of the rectifier bridge stack is respectively connected to the output end of the neon lamp connection unit and the other end of the second capacitor, and is grounded.

[0013] Furthermore, the neon lamp switch unit includes a single-pole double-throw switch, a neon lamp and a seventh resistor; the input end of the single-pole double-throw switch is used to connect to the live wire; the first output end of the single-pole double-throw switch is connected to one end of the neon lamp, and the other end of the neon lamp is connected to one end of the seventh resistor; the second output end of the single-pole double-throw switch is respectively connected to the other end of the seventh resistor and the first input end of the rectifier unit.

[0014] Furthermore, it also includes a fuse resistor; one end of the fuse resistor is connected to the output end of the neon lamp switch unit; the other end of the fuse resistor is connected to the first input end of the rectifier unit.

[0015] The beneficial effects of the utility model are:

[0016] By arranging a neon lamp connection unit after the rectifier unit, when the neon bulb switch is turned off, the neon lamp connection unit can provide a current loop for the neon lamp switch unit, that is, the neon lamp connection unit replaces the existing safety capacitor before the bridge, thereby reducing the volume of the LED driving circuit compatible with the neon bulb switch, reducing the cost, and thus improving the product cost performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a circuit diagram of an LED driving circuit compatible with a neon bulb switch in an embodiment of the present utility model;

[0018] Description of labels:

[0019] 1. Neon lamp switch unit; 2. Rectification unit; 3. Driving unit; 4. Neon lamp connection unit;

[0020] R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the fifth resistor; R6, the sixth resistor; RS, the seventh resistor; IC1, the driver chip; D1, the diode; L1, the inductor; E1, the first capacitor; C1, the second capacitor; S1, the single-pole double-throw switch; LS, the neon lamp; F1, the fuse resistor; BR1, the rectifier bridge stack. DETAILED DESCRIPTION

[0021] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0022] Please refer to Figure 1 , an LED driving circuit compatible with a neon bulb switch, comprising a neon lamp switch unit, a rectifier unit, a drive unit and a neon lamp connection unit; the input end of the neon lamp switch unit is used to connect to a live wire, the output end of the neon lamp switch unit is connected to a first input end of the rectifier unit, and the second input end of the rectifier unit is used to connect to a neutral wire; the first output end of the rectifier unit is respectively connected to a power input end of the drive unit and an input end of the neon lamp connection unit; the second output end of the rectifier unit is connected to an output end of the neon lamp connection unit and is grounded.

[0023] From the above description, it can be seen that the beneficial effect of the utility model is that by arranging a neon lamp connection unit after the rectifier unit, when the neon bulb switch is closed, the neon lamp connection unit can provide a current loop for the neon lamp switch unit, that is, the neon lamp connection unit replaces the existing safety capacitor before the bridge, thereby reducing the volume of the LED driving circuit compatible with the neon bulb switch, reducing the cost, and thus improving the product cost performance.

[0024] Furthermore, it also includes a first resistor, and the neon lamp connection unit includes a second resistor; one end of the first resistor is connected to the first output end of the rectifier unit; the other end of the first resistor is respectively connected to the power input end of the drive unit and one end of the second resistor; the other end of the second resistor is grounded.

[0025] From the above description, it can be seen that by setting the first resistor, the driving unit can be provided with a suitable working voltage and current; by using the second resistor as a neon lamp connection unit, a working circuit can be provided for the neon bulb to reduce the design cost, and by adjusting the resistance value of the second resistor, the suitable working current can be increased for the neon bulb; at the same time, the driving unit can discharge and shunt to the ground through the second resistor, avoiding the problem of increased power consumption and excessive temperature of the driving unit due to the first resistor giving the driving unit too high a voltage when a high voltage is input.

[0026] Furthermore, the driving unit includes a driving chip, a diode, an inductor, a first capacitor and a third resistor; the power input end of the driving chip is respectively connected to the other end of the first resistor and one end of the second resistor; the output end of the driving chip is respectively connected to the positive electrode of the diode and one end of the inductor; the negative electrode of the diode is respectively connected to one end of the first resistor, one end of the first capacitor and one end of the third resistor; the other end of the inductor is respectively connected to the other end of the first capacitor and the other end of the third resistor; the two ends of the first capacitor are used to power the LED light source.

[0027] It can be seen from the above description that a driving circuit with a switch function is formed by arranging a driving chip, a diode, an inductor, a first capacitor and a third resistor to achieve conversion of an input voltage to provide a voltage required by the LED light source.

[0028] Furthermore, a fourth resistor is included; one end of the fourth resistor is connected to the overvoltage protection end of the driving chip, and the other end of the fourth resistor is connected to the second output end of the rectifying unit.

[0029] It can be seen from the above description that the protection voltage is set by the fourth resistor to protect the LED load and prevent it from being impacted by overvoltage surge and causing failure or malfunction.

[0030] Furthermore, it also includes a fifth resistor; one end of the fifth resistor is connected to the over-temperature protection end of the driving chip, and the other end of the fifth resistor is connected to the second output end of the rectifying unit.

[0031] It can be seen from the above description that the over-temperature protection point of the driver chip is set by the fifth resistor, which plays a role in protecting the driver chip and avoiding the problem of damage to the driver chip caused by over-high temperature.

[0032] Furthermore, it also includes a sixth resistor; one end of the sixth resistor is connected to the current control end of the driving chip, and the other end of the sixth resistor is connected to the second output end of the rectifying unit.

[0033] It can be seen from the above description that the LED load current can be adjusted by setting the sixth resistor.

[0034] Furthermore, the rectifier unit includes a rectifier bridge stack and a second capacitor; the first input end of the rectifier bridge stack is connected to the output end of the neon lamp switch unit; the second input end of the rectifier bridge stack is used to connect to the neutral line; the first output end of the rectifier bridge stack is respectively connected to the power input end of the drive unit, the input end of the neon lamp connection unit and one end of the second capacitor; the second output end of the rectifier bridge stack is respectively connected to the output end of the neon lamp connection unit and the other end of the second capacitor, and is grounded.

[0035] It can be seen from the above description that the rectifier unit formed by the rectifier bridge stack and the second capacitor can play an effective rectification role and convert the input alternating current into direct current.

[0036] Furthermore, the neon lamp switch unit includes a single-pole double-throw switch, a neon lamp and a seventh resistor; the input end of the single-pole double-throw switch is used to connect to the live wire; the first output end of the single-pole double-throw switch is connected to one end of the neon lamp, and the other end of the neon lamp is connected to one end of the seventh resistor; the second output end of the single-pole double-throw switch is respectively connected to the other end of the seventh resistor and the first input end of the rectifier unit.

[0037] It can be seen from the above description that the neon lamp switch unit is composed of a single-pole double-throw switch, a neon lamp and a seventh resistor, so that the neon lamp is lit when the switch is placed at the first output end, and the neon lamp is extinguished when the switch is placed at the second output end.

[0038] Furthermore, it also includes a fuse resistor; one end of the fuse resistor is connected to the output end of the neon lamp switch unit; the other end of the fuse resistor is connected to the first input end of the rectifier unit.

[0039] It can be seen from the above description that setting a fuse resistor can protect the circuit by melting the fuse resistor when a circuit fails.

[0040] The LED driving circuit compatible with the neon bulb switch provided by the utility model can be applied to LED lamp scenes, and the following is an explanation through specific implementation methods:

[0041] Embodiment 1

[0042] Please refer to Figure 1A neon bulb switch-compatible LED driving circuit includes a neon lamp switch unit 1, a rectifier unit 2, a drive unit 3, and a neon lamp connection unit 4; the input end of the neon lamp switch unit 1 is used to connect to the live wire (LS) input end, the output end of the neon lamp switch unit 1 is connected to the first input end of the rectifier unit 2, and the second input end of the rectifier unit 2 is used to connect to the neutral wire (NS); the first output end of the rectifier unit 2 is respectively connected to the power input end of the drive unit 3 and the input end of the neon lamp connection unit 4; the second output end of the rectifier unit 2 is connected to the output end of the neon lamp connection unit 4 and is grounded; wherein the circuit is also provided with a fuse resistor F1; one end of the fuse resistor F1 is connected to the output end of the neon lamp switch unit 1; the other end of the fuse resistor F1 is connected to the first input end of the rectifier unit 2.

[0043] In an optional implementation, the driving unit 3 in this embodiment includes a driving chip IC1, a diode D1, an inductor L1, a first capacitor E1, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6; the driving chip IC1 is a main control chip for LED constant current driving; the neon lamp connection unit 4 is a second resistor R2; at the same time, a first resistor R1 is also provided, and the specific connection method is as follows:

[0044] One end of the first resistor R1 is connected to the first output end of the rectifier unit 2; the other end of the first resistor R1 is respectively connected to the power input end (HV) of the drive unit 3 and one end of the second resistor R2; the other end of the second resistor R2 is grounded; the output end (Drain) of the drive chip IC1 is respectively connected to the positive electrode of the diode D1 and one end of the inductor L1; the negative electrode of the diode D1 is respectively connected to one end of the first resistor R1, one end of the first capacitor E1 and one end of the third resistor R3; the other end of the inductor L1 is respectively connected to the other end of the first capacitor E1 and the other end of the third resistor R3; the two ends of the first capacitor E1 are used to The LED light source is powered, i.e., LED+ and LED-; one end of the fourth resistor R4 is connected to the overvoltage protection end (ROVP) of the driver chip IC1, and the other end of the fourth resistor R4 is connected to the second output end of the rectifier unit 2; one end of the fifth resistor R5 is connected to the overtemperature protection end (ROTP) of the driver chip IC1, and the other end of the fifth resistor R5 is connected to the second output end of the rectifier unit 2; one end of the sixth resistor R6 is connected to the current control end (CS) of the driver chip IC1, and the other end of the sixth resistor R6 is connected to the second output end of the rectifier unit 2. The sixth resistor R6 can also be realized by connecting two resistors in parallel.

[0045] Among them, the first resistor R1 is the starting resistor of the driver chip IC1, which provides a power supply path for the power input terminal (HV) of the driver chip IC1. At the same time, by setting the resistance value of the first resistor R1, a suitable working voltage and current can be set for the driver chip IC1; by setting the resistance value of the second resistor R2, it is used to adjust the working current of the neon lamp LS; by setting the resistance value of the fifth resistor R5, it is used to adjust the over-temperature protection point of the driver chip IC1; by setting the resistance value of the fourth resistor R4, it is used to adjust the protection voltage from LED+ to LED- to protect the LED load from overvoltage surge impact failure; by setting the resistance value of the sixth resistor R6, it is used to set the LED load current; the inductor L1 is a power inductor, which plays the role of energy storage and energy transfer in the high-frequency switching circuit, the diode D1 is a freewheeling diode, when the high-frequency switching circuit works in the off state, the energy stored in the inductor L1 is transmitted to the LED loads connected to LED+ and LED- through the freewheeling diode D1, the first capacitor E1 is an electrolytic capacitor that plays the role of energy storage and filtering, and the third resistor R3 is a discharge resistor, which plays a role of rapid discharge when the switch circuit of the driver chip IC1 stops working.

[0046] The neon lamp switch unit 1 includes a single-pole double-throw switch S1, a neon lamp LS and a seventh resistor RS; the input end (pin 2) of the single-pole double-throw switch S1 is used to connect to the live wire; the first output end (pin 3) of the single-pole double-throw switch S1 is connected to one end of the neon lamp LS, and the other end of the neon lamp LS is connected to one end of the seventh resistor RS; the second output end (pin 1) of the single-pole double-throw switch S1 is respectively connected to the other end of the seventh resistor RS and the first input end of the rectifier unit 2.

[0047] The rectifier unit 2 includes a rectifier bridge BR1 and a second capacitor C1; the first input end of the rectifier bridge BR1 is connected to the output end of the neon lamp switch unit 1, that is, connected to the other end of the seventh resistor RS; the second input end of the rectifier bridge BR1 is used to connect to the neutral line; the first output end of the rectifier bridge BR1 is respectively connected to one end of the first resistor R1 and one end of the second capacitor C1, and is used as LED+ for load power supply; the second output end of the rectifier bridge BR1 is respectively connected to the other end of the second resistor R2 and the other end of the second capacitor C1, and is grounded. The rectifier bridge BR1 plays a rectifying role, used to rectify the AC mains into DC power, and the second capacitor C1 is a filtering energy storage circuit.

[0048] The principle of the above-mentioned LED driving circuit compatible with neon bulb switch is as follows:

[0049] The circuit in this embodiment provides a resistive current loop for the neon bulb by connecting the second resistor R2 in the LED drive design; the second resistor R2 can be implemented by a chip resistor, which has the characteristics of small size and low cost, and is more conducive to the wide promotion of the product; when the single-pole double-throw switch S1 is turned to the third foot of S1, the rear-end LED lighting drive circuit is powered off and does not work, and the neon lamp LS for indication is connected. At this time, the neon lamp LS lights up normally through the circuit loop, and the working loop is: LS-single-pole double-throw switch S1-neon lamp LS-seventh resistor RS-fuse resistor F1-rectifier bridge stack BR1-first resistor R1-second resistor R2-bridge stack-NS.

[0050] At the same time, the second resistor R2 is connected between the power input terminal of the driver chip IC1 and the ground line. On the one hand, the second resistor R2 can be used to discharge to the ground, so as to avoid the problem that the current is too large when the neon lamp LS is working, causing the first resistor R1 to charge the driver chip IC1 to the starting voltage and start the back-end LED drive. On the other hand, the driver chip IC1 discharges and shunts to the ground through the second resistor R2, so as to avoid the problem that when the input high voltage is applied, the voltage provided by the first resistor R1 to the driver chip IC1 is too high, resulting in the problem that the driver chip IC1 has increased losses and excessive temperatures.

[0051] Among them, the neon lamp connection unit 4 can also form a loop at other positions of the circuit to achieve the effect of electrically lighting the neon lamp LS. However, because the current of the neon lamp LS is relatively fixed (generally about 1mA), when a resistive loop is formed in other places of the circuit, it is usually connected to a high-voltage loop. According to P=UI, since the current is fixed at about 1mA and the voltage is high voltage, the power loss is large. In addition, since the neon lamp LS current loop is connected in parallel in the circuit, while the neon lamp LS is working, it will also charge the power supply pin of the circuit driver chip IC1 synchronously. When the voltage reaches the IC1 starting voltage, it will trigger the lamp to start by mistake.

[0052] The neon lamp circuit in this embodiment is realized by connecting a second resistor R2 in series between the power input terminal of the driver chip IC1 and the ground line. Since the voltage of the power input terminal (HV) of the driver chip IC1 is lower than the voltage of the high-voltage circuit (generally a low voltage of 20-50V), according to P=UI, since the current is fixed at about 1mA and the voltage is low, the power loss is small; and the problem of false triggering can also be solved.

[0053] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. An LED driving circuit compatible with neon bulb switch, characterized in that: It includes a neon lamp switch unit, a rectifier unit, a drive unit and a neon lamp connection unit; The input end of the neon lamp switch unit is used to connect to the live wire, the output end of the neon lamp switch unit is connected to the first input end of the rectifier unit, and the second input end of the rectifier unit is used to connect to the neutral wire; The first output end of the rectifier unit is connected to the power input end of the drive unit and the input end of the neon lamp connection unit respectively; The second output end of the rectifying unit is connected to the output end of the neon lamp connecting unit and is grounded.

2. The LED driving circuit compatible with neon bulb switch according to claim 1, characterized in that: It also includes a first resistor, and the neon lamp communication unit includes a second resistor; One end of the first resistor is connected to the first output end of the rectifier unit; The other end of the first resistor is connected to the power input end of the driving unit and one end of the second resistor respectively; The other end of the second resistor is grounded.

3. The LED driving circuit compatible with neon bulb switch according to claim 2, characterized in that: The driving unit includes a driving chip, a diode, an inductor, a first capacitor and a third resistor; The power input terminal of the driving chip is respectively connected to the other end of the first resistor and one end of the second resistor; The output end of the driving chip is connected to the anode of the diode and one end of the inductor respectively; The cathode of the diode is respectively connected to one end of the first resistor, one end of the first capacitor and one end of the third resistor; The other end of the inductor is respectively connected to the other end of the first capacitor and the other end of the third resistor; The two ends of the first capacitor are used to power the LED light source.

4. The LED driving circuit compatible with neon bulb switch according to claim 3, characterized in that: The driving unit further includes a fourth resistor; One end of the fourth resistor is connected to the overvoltage protection end of the driving chip, and the other end of the fourth resistor is connected to the second output end of the rectifying unit.

5. The LED driving circuit compatible with neon bulb switch according to claim 3, characterized in that: The driving unit further includes a fifth resistor; One end of the fifth resistor is connected to the over-temperature protection end of the driving chip, and the other end of the fifth resistor is connected to the second output end of the rectifying unit.

6. The LED driving circuit compatible with neon bulb switch according to claim 5, characterized in that: The driving unit further includes a sixth resistor; One end of the sixth resistor is connected to the current control end of the driving chip, and the other end of the sixth resistor is connected to the second output end of the rectifying unit.

7. The LED driving circuit compatible with neon bulb switch according to claim 1, characterized in that: The rectifier unit includes a rectifier bridge stack and a second capacitor; The first input end of the rectifier bridge stack is connected to the output end of the neon lamp switch unit; The second input end of the rectifier bridge stack is used to be connected to the neutral line; The first output end of the rectifier bridge stack is respectively connected to the power input end of the driving unit, the input end of the neon lamp connection unit and one end of the second capacitor; The second output end of the rectifier bridge stack is respectively connected to the output end of the neon lamp connection unit and the other end of the second capacitor, and is grounded.

8. The LED driving circuit compatible with neon bulb switch according to claim 1, characterized in that: The neon lamp switch unit comprises a single-pole double-throw switch, a neon lamp and a seventh resistor; The input end of the single-pole double-throw switch is used to connect to the live wire; The first output end of the single-pole double-throw switch is connected to one end of the neon lamp, and the other end of the neon lamp is connected to one end of the seventh resistor; The second output end of the single-pole double-throw switch is connected to the other end of the seventh resistor and the first input end of the rectifying unit respectively.

9. The LED driving circuit compatible with neon bulb switch according to claim 1, characterized in that: Also includes a fuse resistor; One end of the safety resistor is connected to the output end of the neon lamp switch unit; The other end of the safety resistor is connected to the first input end of the rectifier unit.

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