Color temperature control circuit

Abstract

The utility model provides a color temperature control circuit. The color temperature control circuit comprises a power supply circuit, an LED circuit and a color temperature selection circuit which are connected in series, wherein the color temperature selection circuit comprises a multi-path change-over switch and an adjusting circuit, the multi-path change-over switch is provided with at least two branches, at least one of the branches of the multi-path change-over switch is connected with the adjusting circuit in series, the adjusting circuit comprises a resistor and a first diode which are connected in series, and when the at least two branches of the multi-path change-over switch are connected with the adjusting circuit in series, the resistor is connected with the first diode. Resistance values of the resistors connected in the adjusting circuits of different branches of the multi-path change-over switch in series are different. Different adjusting circuits are selected through the multi-path change-over switch, the resistance values of the resistors in the adjusting circuits of different branches are different, the purpose of adjusting the color temperature is achieved by changing the resistance values of the resistors, and flexible color temperature adjustment is achieved. The color temperature selection circuit is simple and reliable in circuit structure, flexible and easy to maintain.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lighting, in particular to a color temperature control circuit. BACKGROUND

[0002] In traditional LED lighting, especially for occasions requiring color temperature adjustment, multi-color temperature switching is often dependent on a complex electronic control system, of which the most common is to use a single-chip microcomputer as a control center, cooperating with a power main control chip, to output different currents to the connected high and low color temperature LEDs, so as to obtain the required color temperature. However, this single-chip microcomputer control scheme is high in cost and needs to re-adjust the single-chip microcomputer program to meet different color temperature requirements, which is relatively complex. CONTENT OF THE UTILITY MODEL

[0003] The embodiment of the present application provides a color temperature control circuit based on resistance circuit control, which realizes multi-gear color temperature adjustment, so as to solve the problems of high cost and complex debugging of traditional LED color temperature adjustment relying on a single-chip microcomputer and a main control chip to achieve color temperature adjustment.

[0004] The present application provides a color temperature control circuit, which comprises a power supply circuit, an LED circuit and a color temperature selection circuit connected in series; wherein the color temperature selection circuit comprises a multi-way switch and an adjustment circuit, the multi-way switch has at least two branches, at least one branch of the multi-way switch is connected with the adjustment circuit, and the adjustment circuit is a series connection of a first resistor and a first diode.

[0005] In a feasible implementation manner, when at least two branches of the multi-way switch are connected with the adjustment circuit, the resistance values of the first resistors in the color temperature adjustment circuits connected in series in different branches of the multi-way switch are different.

[0006] In a feasible implementation manner, the LED circuit comprises at least one LED branch, each LED branch is connected with the color temperature selection circuit, and when the LED circuit comprises at least two LED branches, the LED branches are connected in parallel with each other.

[0007] In a feasible implementation manner, one end of the LED branch is connected with the positive pole of the power supply circuit, and the other end of the LED branch is connected with the positive pole of the first diode in the adjustment circuit or the first contact of the multi-way switch; when the other end of the LED branch is connected with the positive pole of the first diode in the adjustment circuit, the negative pole of the first diode is connected with one end of the first resistor, the other end of the first resistor is connected with the first contact of the multi-way switch, and the second contact of the multi-way switch is grounded.

[0008] In an implementation, the power supply circuit comprises a rectifier circuit and a plurality of control units, the plurality of control units are connected in parallel, outputs of the rectifier circuit are connected to inputs of the plurality of control units respectively, and outputs of the plurality of control units are connected to the LED circuit.

[0009] In an implementation, a second diode is connected in series between the outputs of the plurality of control units and the LED circuit.

[0010] In an implementation, the power supply circuit further comprises a filter circuit, one end of the filter circuit is connected between the output of the rectifier circuit and the input of the plurality of control units, and the other end of the filter circuit is grounded.

[0011] In an implementation, the power supply circuit further comprises a voltage stabilizing circuit, one end of the voltage stabilizing circuit is connected between the output of the plurality of control units and the LED circuit, and the other end of the voltage stabilizing circuit is grounded.

[0012] In an implementation, the voltage stabilizing circuit comprises an electrolytic capacitor and a third diode, a positive electrode of the electrolytic capacitor is connected to a positive electrode of the third diode, a negative electrode of the electrolytic capacitor is grounded, and a negative electrode of the third diode is connected to a positive electrode of the LED.

[0013] In an implementation, the rectifier circuit is a bridge rectifier circuit.

[0014] In an implementation, a pressure-sensitive resistor is connected in parallel to the input of the rectifier circuit.

[0015] Compared with the prior art, the present application has at least the following beneficial effects:

[0016] The color temperature control circuit provided by the present application comprises a power supply circuit, an LED circuit and a color temperature selection circuit connected in series. The color temperature selection circuit comprises a plurality of multipath switches and adjusting circuits, each branch of the plurality of multipath switches is connected in series with an adjusting circuit, and different adjusting circuits are selected by the plurality of multipath switches, so that the color temperature adjustment can be flexibly realized. The adjusting circuit comprises a resistor and a first diode connected in series, the resistors in different branches of the adjusting circuit have different resistance values, and the color temperature adjustment is realized by changing the resistance values of the resistors, which is simple and reliable. The color temperature control circuit provided by the present application has flexibility, high reliability, and is easy to implement and maintain. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0018] Figure 1 is a schematic diagram of a color temperature control circuit connection structure provided by the embodiments of the present application;

[0019] Figure 2 is a schematic diagram of a color temperature control circuit provided by the embodiments of the present application;

[0020] Figure 3 is a schematic diagram of a color temperature control circuit provided by another embodiment of the present application.

[0021] Explanation of reference signs:

[0022] 100-power supply circuit; 110-rectifier circuit; 120-control unit; 130-filter circuit; 140-voltage stabilizing circuit; 200-LED circuit; 210-first LED branch; 220-second LED branch; 300-color temperature selection circuit; 310-regulation circuit. DETAILED DESCRIPTION

[0023] In order to make the person skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort should belong to the scope of protection of the present application.

[0024] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0025] The main working principle of the current mainstream multi-color temperature position LED power supply is to control the power main control chip by the single-chip microcomputer, output different currents to the high and low color temperature lamp beads, so as to obtain the required color temperature. This scheme has high cost, and needs to re-adjust the single-chip microcomputer program to meet different color temperature requirements, which is relatively complex. The color temperature control circuit provided by the present application controls the color temperature based on the resistance circuit, realizes multi-position color temperature adjustment by changing the resistance value of the LED circuit in series, and has simple and reliable circuit structure, flexible color temperature adjustment, high reliability, and is easy to implement and maintain.

[0026] The specific structure of the color temperature control circuit provided by the present application will be described in detail in combination with the drawings as follows.

[0027] Embodiment 1:

[0028] Referring to Figure 1 shown, Figure 1 is a schematic diagram of a color temperature control circuit connection structure provided by an embodiment of the present application. The color temperature control circuit provided by the embodiment of the present application comprises a power supply circuit 100, an LED circuit 200 and a color temperature selection circuit 300 connected in series. The LED circuit comprises at least one LED branch, and when a plurality of LED branches are included, the plurality of LED branches are connected in parallel. As an example, in the embodiment, the LED circuit comprises two LED branches, which are a first LED branch 210 and a second LED branch 220. The first LED branch 210 is a high color temperature LED branch, and the second LED branch 220 is a low color temperature LED branch.

[0029] Continuing to refer to Figure 1 shown, when a plurality of LED branches are included, the color temperature selection circuit 300 is connected in series in each LED branch. The color temperature selection circuit 300 connected in series in each LED branch realizes color temperature control of the LED branch.

[0030] Referring to Figure 2 shown, Figure 2 is a schematic diagram of a color temperature control circuit provided by an embodiment of the present application. Each color temperature selection circuit 300 comprises a plurality of switching switches and an adjusting circuit 310, and the adjusting circuit 310 is connected in series with different branches of the switching switch. The adjusting circuit 310 comprises a first resistor and a first diode connected in series, and the resistance values of the first resistors of the adjusting circuits 310 connected in series with different branches of the switching switch are different. The switching switch can switch between different adjusting circuits 310, so as to change the resistance value of the LED circuit, and then the current of the LED circuit is adjusted, so as to realize color temperature control.

[0031] As an example, in the embodiment, the switch SW2 comprises two switching switches, which are referred to as a first switching switch and a second switching switch for convenience of description, and the first switching switch and the second switching switch work independently. The first switching switch is connected in series with the first LED branch (high color temperature LED branch), so as to realize color temperature control of the first LED branch (high color temperature LED branch). The second switching switch is connected in series with the second LED branch (low color temperature LED branch), so as to realize color temperature control of the second LED branch (low color temperature LED branch).

[0032] In the embodiment, each of the plurality of switches is connected in series with three different color temperature adjustment circuits 310. In the adjustment circuit 310 connected to pin 11 of the first switch, the first resistor is resistor R11 and the first diode is diode D3; in the adjustment circuit 310 connected to pin 9 of the first switch, the first resistor is resistor R12 and the first diode is diode D4; in the adjustment circuit 310 connected to pin 8 of the first switch, the first resistor is resistor R13 and the first diode is diode D5. In the adjustment circuit 310 connected to pin 2 of the second switch, the first resistor is resistor R8 and the first diode is diode D6; in the adjustment circuit 310 connected to pin 4 of the second switch, the first resistor is resistor R9 and the first diode is diode D7; in the adjustment circuit 310 connected to pin 5 of the second switch, the first resistor is resistor R10 and the first diode is diode D8. The resistors R8, R9 and R10 have different resistance values, and the resistors R11, R12 and R13 have different resistance values. Therefore, when the switches are switched, the resistance values of the resistors connected to the LED circuit are different, the current flowing into the LED lamp is different, and the color temperature is achieved.

[0033] The plurality of switches has two types of contacts, which are referred to as first contacts and second contacts for convenience of description. The first contacts are a plurality of contacts for connecting the adjustment circuits or directly connecting the LED circuit, and the second contact is one contact for connecting the negative pole of the power supply to form a loop. In the embodiment, the first switch has pins 7, 8, 9, 10, 11 and 12, and the second switch has pins 1, 2, 3, 4, 5 and 6. The pin 10 of the first switch and the pin 3 of the second switch are the second contacts, and the remaining pins of the first switch and the second switch are the first contacts. When the switch is closed, the first contacts are directly or indirectly connected to the second contact to form a loop. As an example, when the first switch is switched to pin 11, the pin 11 is connected to the pin 10, the adjustment circuit with resistor R11 and diode D3 is connected to the first LED branch, and thus the current of the first LED branch is changed. Similarly, when the first switch is switched to pins 8 and 9, the first resistors in the adjustment circuits 310 are R12 and R13, respectively. Because the resistance values of R12 and R13 are different, the current of the first LED branch is changed. When the first switch is switched to pin 2, the first LED branch is not connected to the adjustment circuit 310, and thus the current in the first LED branch is different from that when the first LED branch is connected to the adjustment circuit. The second switch controls the current of the second LED branch in the same way as the first switch, and as a person skilled in the art can understand, the description is not repeated here.

[0034] A light-emitting diode (LED) is a semiconductor device with unidirectional conductivity and light-emitting properties. The brightness of an LED is directly affected by the amount of current. Within its normal operating range, a larger current increases the LED's brightness, while a smaller current decreases it. Changes in current can also alter the spectral distribution of the LED. This is because different wavelengths of light may have different emission efficiencies within the LED, and changes in current can alter the proportions of these efficiencies. This change results in a shift in the color of the emitted light, manifesting as a change in color temperature.

[0035] Therefore, when the current in the first LED branch and / or the second LED branch changes, the light emitted by the LED circuit 200 will produce a new color temperature effect. Understandably, by precisely adjusting the current ratio of the first LED branch and the second LED branch, a series of different mixed color temperatures can be obtained to meet the needs of different application scenarios.

[0036] Continue to refer to Figure 2 As shown, in this embodiment, the LED circuit 200 includes two LED branches, namely the first LED branch 210 and the second LED branch 220. Each LED branch includes multiple light-emitting diodes connected in series, wherein the first LED branch includes light-emitting diodes LED1 to LED9, and the second LED branch includes light-emitting diodes LED10 to LED18.

[0037] In the first LED branch 210, the positive terminal of the power supply circuit 100 is connected to the positive terminal of LED1, and the negative terminal of LED9 is connected to the positive terminals of diodes D3, D4, and D5, respectively, and pin 2 of the second multiplexer. In the second LED branch 220, the positive terminal of the power supply circuit 100 is connected to the positive terminal of LED10, and the negative terminal of LED18 is connected to the positive terminals of diodes D6, D7, and D8, respectively, and pin 6 of the second multiplexer. Pin 10 of the first multiplexer and pin 4 of the second multiplexer are grounded to form a loop.

[0038] The color temperature control circuit provided in this application can achieve color temperature adjustment by selecting different adjustment circuits through a multi-channel switching switch. The circuit structure is simple and reliable, does not require microcontroller control, and is easy to debug.

[0039] Continue to refer to Figure 2As shown, in the present application, the power supply circuit 100 comprises a rectifier circuit 110 and a plurality of control units 120, the plurality of control units 120 are connected in parallel, the output end of the rectifier circuit 110 is connected with the input end of the plurality of control units 120, and the output end of the plurality of control units 120 is connected with the LED circuit. A second diode (i.e. diode D1, referred to as diode D1 in the following description) is connected in series between the output end of the plurality of control units 120 and the LED circuit 200. The diode D1 has unidirectional conductivity, preventing reverse current.

[0040] In some embodiments, the power supply circuit 100 further comprises a filter circuit 130, one end of the filter circuit 130 is connected between the output end of the rectifier circuit 110 and the input end of the plurality of control units 120, and the other end of the filter circuit 130 is grounded. The filter circuit 130 comprises a pressure-sensitive resistor RV2 and a capacitor C1 connected in parallel, wherein one end of the pressure-sensitive resistor RV2 and the capacitor C1 is connected between the output end of the rectifier circuit 110 and the input end of the control unit 120, and the other end of the pressure-sensitive resistor RV2 and the capacitor C1 is grounded.

[0041] In some embodiments, the power supply circuit 100 further comprises a voltage stabilizing circuit 140, one end of the voltage stabilizing circuit 140 is connected between the output end of the plurality of control units 120 and the LED circuit 200, and the other end of the voltage stabilizing circuit 140 is grounded. The voltage stabilizing circuit comprises an electrolytic capacitor EC1, a resistor R5, a resistor R6, a resistor R7 and a third diode (i.e. diode D2, referred to as diode D2 in the following description), the first end of the resistor R5 is connected between the output end of the control unit 120 and the LED circuit 200, the second end of the resistor R5 is connected to the positive electrode of the electrolytic capacitor EC1, the negative electrode of the electrolytic capacitor EC1 is grounded, the first end of the resistor R6 is connected with the first end of the resistor R5, the second end of the resistor R6 is respectively connected to the second end of the resistor R5 and the first end of the resistor R7, and the second end of the resistor R7 is grounded. The positive electrode of the diode D2 is respectively connected to the positive electrode of the electrolytic capacitor EC1, the second end of the resistor R5 and the second end of the resistor R6, and the negative electrode of the diode D2 is connected with the first end of the resistor R5.

[0042] In some embodiments, the rectifier circuit 110 is a bridge rectifier circuit.

[0043] In some embodiments, the input end of the rectifier circuit 110 is connected in parallel with a pressure-sensitive resistor RV1 for overvoltage protection, improving circuit stability and preventing external interference.

[0044] Embodiment 2:

[0045] In this embodiment, only the different parts of embodiment 1 are described, and the same content is not described again.

[0046] Reference Figure 3As shown, in the embodiment, the switch SW2 is a linkage switch. The switch SW2 includes two multi-way switches, for the convenience of description, respectively referred to as a first multi-way switch and a second multi-way switch, the first multi-way switch and the second multi-way switch work in linkage. That is, when the first multi-way switch is switched, the second multi-way switch is synchronously operated, and when the second multi-way switch is switched, the first multi-way switch is synchronously operated. In some embodiments, the two multi-way switches in the switch SW2 are linkage switches, and each operation of the switch SW2 can realize the synchronous switching of the first multi-way switch and the second multi-way switch. At this time, the resistance ratio of the first LED branch (high color temperature LED branch) and the second LED branch (low color temperature LED branch) is fixed, and several fixed color temperatures can be mixed.

[0047] In a determined application site, that is, only several fixed color temperature changes are needed, by setting the linkage switch, the color temperature debugging operation is further simplified, and the use is more convenient. In some embodiments, the first multi-way switch and the second multi-way switch in the switch SW2 are mechanically linked, when one of the multi-way switches is in a certain state, some states of the other switch will be locked. As known by those skilled in the art, the mechanical structure of the linkage switch of the switch SW2 is not described herein.

[0048] It is easy to understand that those skilled in the art can combine, split, recombine, etc. the embodiments of the present application on the basis of the several embodiments provided by the present application to obtain other embodiments, and these embodiments do not exceed the protection scope of the present application.

[0049] The above specific embodiments have further described the purposes, technical solutions and beneficial effects of the embodiments of the present application. It should be understood that the above is only a specific embodiment of the present application, and is not used to limit the protection scope of the embodiments of the present application. Any modification, equivalent replacement, improvement, etc. made on the basis of the technical solutions of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A color temperature control circuit, characterized by, The application relates to a color temperature selection circuit, which comprises a power supply circuit, an LED circuit and a color temperature selection circuit connected in series; wherein the color temperature selection circuit comprises a multipath switch and an adjusting circuit, the multipath switch has at least two branches, at least one branch of the multipath switch is connected with the adjusting circuit, and the adjusting circuit is a first resistor and a first diode connected in series.

2. The color temperature control circuit of claim 1, wherein, When at least two branches of the multipath switch are connected with the adjusting circuit, the resistance values of the first resistors of the adjusting circuits connected in series in different branches of the multipath switch are different.

3. The color temperature control circuit of claim 1, wherein, The LED circuit comprises at least one LED branch, each LED branch is connected with the color temperature selection circuit, and when the LED circuit comprises at least two LED branches, the LED branches are connected in parallel with each other.

4. The color temperature control circuit of claim 3, wherein, One end of the LED branch is connected with the positive pole of the power supply circuit, and the other end of the LED branch is connected with the positive pole of the first diode in the adjusting circuit or the first contact of the multipath switch; when the other end of the LED branch is connected with the positive pole of the first diode in the adjusting circuit, the negative pole of the first diode is connected with one end of the first resistor, the other end of the first resistor is connected with the first contact of the multipath switch, and the second contact of the multipath switch is grounded.

5. The color temperature control circuit of claim 4, wherein, The power supply circuit comprises a rectifier circuit and a plurality of control units, the plurality of control units are connected in parallel, the output ends of the plurality of control units are connected with the input ends of the plurality of control units respectively, and the output ends of the plurality of control units are connected with the LED circuit.

6. The color temperature control circuit of claim 5, wherein, A second diode is connected in series between the output ends of the plurality of control units and the LED circuit.

7. The color temperature control circuit of claim 5, wherein, The power supply circuit comprises a filter circuit, one end of the filter circuit is connected between the output end of the rectifier circuit and the input end of the plurality of control units, and the other end of the filter circuit is grounded.

8. The color temperature control circuit of claim 5, wherein, The power supply circuit comprises a voltage stabilizing circuit, one end of the voltage stabilizing circuit is connected between the output end of the plurality of control units and the LED circuit, and the other end of the voltage stabilizing circuit is grounded.

9. The color temperature control circuit of claim 8, wherein, The voltage stabilizing circuit comprises an electrolytic capacitor and a third diode, the positive pole of the electrolytic capacitor is connected with the positive pole of the third diode, the negative pole of the electrolytic capacitor is grounded, and the negative pole of the third diode is connected with the input end of the LED circuit.

10. The color temperature control circuit of claim 5, wherein, The input end of the rectifier circuit is connected with a pressure-sensitive resistor in parallel.

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