JP3146976U - LED control circuit - Google Patents

Abstract

A light emitting diode control circuit is provided.
A light emitting diode control circuit provided by the present invention includes a light emitting diode circuit and a control circuit. The light emitting diode circuit includes a light emitting diode and a field effect tube interconnected with the light emitting diode. The control circuit is connected to the microcontroller and the microcontroller, and has a temperature sensor installed in the vicinity of the light-emitting diode. The microcontroller and the field effect tube are connected to each other to control the field effect tube. The temperature sensor senses the temperature of the light emitting diode, and then transmits a temperature signal to the microcontroller. The microcontroller controls on / off of the field effect tube based on the temperature signal. The light-emitting diode control circuit of the present invention controls the luminance of the light-emitting diode by means of a temperature sensor, a microcontroller, and a field effect tube.
[Selection] Figure 1

Description

  The present invention relates to a control circuit, and more particularly to a light emitting diode control circuit.

  Conventional electrical appliances widely use light emitting diodes as their operating status indicators or illumination lamps. The conventional control of the luminance of the light emitting diode usually employs a current control method, that is, the control of the luminance of the light emitting diode is realized through a change in the current of the light emitting diode.

  As shown in FIGS. 2 and 3, the Chinese patent application No. 200710002657 discloses a compensation circuit that controls the brightness of a light emitting diode using a current control method, and includes a reference voltage generator. 100 ′ is used to generate the first reference voltage Vref1, and the positive voltage detector 500 ′ is used to monitor the positive voltage Vf of the light-emitting diode light source 400 ′, and the non-inverting amplification of the positive voltage Vf. Provided to the unit 200 ′, the non-inverting amplification unit 200 ′ uses a predetermined amplifier to perform non-inverting amplification on the voltage difference between the first reference voltage Vref1 and the positive voltage Vf, and after non-inverting amplification Is compared to the second reference voltage of current limiter 600 ′ (shown in FIG. 3), and finally, a suitable voltage is provided to drive unit 300 ′, so that drive unit 300 ′ It controls source voltage, to achieve the control of the brightness of the LEDs.

However, the circuit structure is complicated, has a large occupied space, is expensive, and does not meet the requirements for downsizing and cost reduction of electronic products.
Chinese patent application number 200710002657 specification

  An object of the present invention is to provide a light-emitting diode control circuit that has a simple structure with respect to the defects existing in the background art, a small occupied space, and a low cost.

In order to achieve the above object, a light emitting diode control circuit provided by the present invention includes a light emitting diode circuit and a control circuit. The light emitting diode circuit includes a light emitting diode and a field effect tube interconnected with the light emitting diode. The control circuit is connected to the microcontroller and the microcontroller, and has a temperature sensor installed in the vicinity of the light-emitting diode. The microcontroller and the field effect tube are connected to each other to control the field effect tube. The temperature sensor senses the temperature of the light emitting diode, and then transmits a temperature signal to the microcontroller. The microcontroller controls on / off of the field effect tube based on the temperature signal.
That is, the present invention has the following features.
(1) a light emitting diode circuit having a light emitting diode and a field effect tube interconnected with the light emitting diode;
The microcontroller and the microcontroller are connected to each other and have a temperature sensor installed in the vicinity of the light emitting diode. The microcontroller and the field effect tube are connected to each other to control the field effect tube and the temperature The sensor senses the temperature of the light emitting diode, and then transmits a temperature signal to the microcontroller, and the microcontroller controls the on / off of the field effect tube based on the temperature signal; and
A light emitting diode control circuit.
(2) The light emitting diode control circuit according to (1), wherein the control circuit is connected to an audio control circuit, and the audio control circuit has an audio signal collecting end.
(3) The light emitting diode control circuit according to (1), wherein the microcontroller is connected to a manual switch.
(4) The light emitting diode control circuit according to (1), wherein one end of the light emitting diode is connected to a transformer circuit.
(5) The light emitting diode control circuit according to (1), wherein a constant current source is connected between the transformer circuit and the light emitting diode.
(6) The light emitting diode control circuit according to (1), wherein there are three light emitting diodes, and each of the three light emitting diodes can emit red, green, and blue.

  As described above, the light emitting diode control circuit of the present invention senses the temperature of the light emitting diode by the temperature sensor, and then transmits the temperature signal to the microcontroller, and the microcontroller makes an analysis judgment on the temperature signal. Doing, thereby controlling the field effect tube on or off, controlling the average current of the light emitting diode, realizing control over the brightness of the light emitting diode, the structure in the light emitting diode control circuit of the above prior art is complicated, Since a large volume non-inverting amplifier unit and a current limiting device are not required, the LED controller circuit structure of the present invention is relatively simple, occupies a small space and is low in cost.

  In order to describe the technical contents, structural features, objects to be achieved, and effects of the present invention in detail, examples will be given below and described in detail with reference to the drawings.

  As shown in FIG. 1, the light emitting diode control circuit 1 of the present invention includes a transformer circuit 10, a light emitting diode 20, a control circuit 30, and an audio control circuit 40.

  The transformer circuit 10 includes a transformer module U6 and capacitors C1, C2, C4 used as filters. The voltage transformation module U6 is connected to the power source Vcc. The power source Vcc transforms the voltage via the voltage transformation module U6, and then supplies power to the light emitting diode 20, the control circuit 30 and the voice control circuit 40 via the filtering of the capacitors C2 and C4. To do.

  The light emitting diode circuit 20 includes three parallel paths, and the first path includes, in order, a constant current source U1, a resistor R1, a red diode D1, and a field effect tube Q1. The second path includes a constant current source U2, a resistor R2, a green diode D2, and a field effect tube Q2 in series. The second path includes a constant current source U3, a resistor R3, a blue diode D3, and a field effect tube Q3 in series. Among them, one end of the constant current source U1, constant current source U2, constant current source U3 is connected to the transformer circuit 10, and in this embodiment, the feel effect tubes Q1, Q2, Q3 are all N-groove enhanced metal An oxide field effect tube with a drain connected to a corresponding light emitting diode and a source grounded.

  The constant current sources U1, U2 and U3 provide stable currents in the corresponding paths, and after dividing the voltages through the corresponding resistors R1, R2 and R3, supply power to the corresponding light emitting diodes. The red diode D1, the green diode D2, and the blue diode D3 are installed together to form a light emitting diode module, and when current flows through the red diode D1, the green diode D2, and the blue diode D3, red, green, Emits blue color. Further, the temperature rise rates of the red diode D1, the green diode D2, and the blue diode D3 based on the increase in the light emission time are different. In the present embodiment, when the current passes through the light emitting diode group, the temperature rise rate of the red diode D1 is faster than the temperature rise rate of the green diode D2, and the temperature rise rate of the green diode D2 is that of the blue diode D3. Faster than the temperature rise rate.

  The control circuit 30 is connected to the microcontroller U4 and the microcontroller U4, and has a numeric temperature sensor TH installed near the light emitting diode. In this embodiment, the microcontroller U4 is a single chip computer having pins 1 to 8, of which the first pin is connected to the transformer circuit 10 and from inside the transformer circuit 10. Obtain the supply voltage, the 2nd pin is connected to the gate of the field effect Q1, the 3rd pin is connected to the audio control circuit 40, the 4th pin is connected to the manual switch SW1, and the 5th pin is Are connected to the gate of the field effect tube Q3, the 6th pin is connected to the gate of the field effect tube, the 7th pin is connected to the temperature sensor TH, and the 8th pin is grounded.

  One end of the temperature sensor TH is grounded. The temperature sensor TH senses the temperature of the light emitting diode set, generates a temperature signal, and transmits the temperature signal to the microcontroller U4. The microcontroller U4 is based on the order of the temperature signals transmitted by the temperature sensor TH. , Output high level or low level to the 2nd pin, 6th pin or 5th pin, respectively, to control the on / off of the field effect tubes Q1, Q2, Q3, thereby red diode D1, green diode D2, blue Control of the average current of the diode D3 is realized, and finally control of the luminance of the light emitting diode is realized.

  For example, after the light emitting diode group operates for a certain time, the temperature of the red diode D1 rises, and the resistance and light emission luminance increase. At this time, the microcontroller U4 determines the temperature of the light emitting diode through the temperature sensor TH. The higher value is first sensed, thereby generating a temperature signal corresponding to the high temperature and transmitting the temperature signal to the microcontroller U4, which sends a series of high and low level signals to the second pin. The output is placed in the field effect tube Q1 in an on / off state without interruption, the average current of the red diode D1 is controlled, the average current is set to a fixed value, and finally the luminance of the red diode D1 is controlled. To do. When the field effect Q1 is in the on and off state without interruption, the human eye basically cannot distinguish the flash of the red diode D1.

  When the temperature sensor TH detects that the temperature of the light emitting diode set becomes higher than a predetermined value at the second time or the third time, the microcontroller U4 controls the average current of the green diode D2 and the blue diode D3, respectively. Control over the brightness of D2 and blue diode D3 is realized. When the temperature sensor TH senses that the temperature of the light emitting diode group becomes higher than the set value for the fourth time and thereafter, the microcontroller U4 simultaneously controls the currents of the red diode D1, the green diode D2, and the blue diode D3. The method performed is the same as the control for the red diode and will not be described again here.

  The voice control circuit 40 includes a transistor tube Q5, resistors R4, R5, R6, and R7, a capacitor C5, and an audio signal collecting terminal phone_in. The emitter of the transistor Q5 is grounded, the collector is connected to the third pin of the microcontroller U4, and the base is connected to the audio signal collecting terminal phone_in via the capacitor C5. One end of the resistor R4 is connected to the transformer circuit 10, and the other end is connected to the capacitor C5. One end of the resistor R5 is connected to the output end of the transformer circuit 10, and the other end is connected to one end of a collector far from the transistor Q5 of the capacitor C5. One end of the transistor R6 is connected to the output end of the transformer circuit 10, and the other end is connected to one end of the collector of the transistor Q5. One end of the resistor R7 is connected to one end of a collector far from the transistor Q5 of the capacitor C5, and the other end is grounded.

  When the audio signal collection end phone_in collects an audio signal, the base potential of the transistor Q5 becomes high, and thereby the collector of the transistor Q5 emits a low level signal to the third pin of the microcontroller U4. U4 controls the level of pin 2, pin 5 and pin 6, based on the duration of the low level signal on pin 3, and realizes control of red diode D1, green diode D2 and blue diode D3, respectively. In combination with light emitting diodes, various different colors are emitted. For example, when collecting an audio signal whose audio signal collection end phone_in lasts within 1 second within an arbitrary 3 seconds, it is extinguished with respect to the red diode D1 through the control of the microcontroller U4, and the green diode D2 and the blue diode The light emission of D3 is retained, thereby synthesizing one kind of color. When the audio signal collection end phone_in collects an audio signal that lasts within 2 seconds, it is extinguished with respect to the green diode D2 through the control of the microcontroller U4, and the emission of the red diode D1 and the blue diode D3 is held. To synthesize another color. In this embodiment, the calculation of the audio signal duration of the microcontroller U4 is realized by calculating the command cycle time in the microcontroller U4. The manual switch SW1 can control the level of the 4th pin of the microcontroller U4, thereby performing a reversion operation on the microcontroller U4.

  As described above, the light-emitting diode control circuit 1 according to the present invention is a large-area module circuit such as a conventional non-inverting amplification unit, a forward voltage detector, and a source device in the background art by the temperature sensor TH and the microcontroller U4. Therefore, the light emitting diode control circuit 1 of the present invention has a simple structure, a small occupied space, and a low cost.

In the present invention, the preferred embodiments have been disclosed as described above, but these are not intended to limit the present invention in any way, and anyone who is familiar with the technology can make an equivalent scope without departing from the spirit and scope of the present invention. Of course, various fluctuations and hydration colors can be added. For example, the single piece machine can be another microcontroller, the temperature sensor and the light emitting diode can be grounded correspondingly in one or more sets, and so on.

1 is a circuit principle diagram of an embodiment of a light emitting diode control circuit according to the present invention; It is a circuit principle figure of the Example of the conventional light emitting diode control circuit. FIG. 3 is a circuit principle diagram of a current limiter of the light emitting diode control circuit shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting diode control circuit 10 Transformer circuit 20 Light emitting diode circuit 30 Control circuit 40 Audio control circuit Q5 Transistor tube U4 Microcontroller SW1 Manual switch Vcc Power supply U6 Transformer module TH Temperature sensor D1 Red diode D2 Green diode D3 Blue diode phone_in Audio signal collection End Q1, Q2, Q3 Field effect tube U1, U2, U3 Constant current source C1, C2, C3, C4, C5 Capacitor R1, R2, R3, R4, R5, R6, R7 Resistance

Claims (6)

A light emitting diode circuit having a light emitting diode and a field effect tube interconnected with the light emitting diode;
The microcontroller and the microcontroller are connected to each other and have a temperature sensor installed in the vicinity of the light emitting diode. The microcontroller and the field effect tube are connected to each other to control the field effect tube and the temperature The sensor senses the temperature of the light emitting diode, and then transmits a temperature signal to the microcontroller, and the microcontroller controls the on / off of the field effect tube based on the temperature signal; and
A light emitting diode control circuit. 2. The light emitting diode control circuit according to claim 1, wherein the control circuit is connected to an audio control circuit, and the audio control circuit has an audio signal collecting end. 2. The light emitting diode control circuit according to claim 1, wherein the microcontroller is connected to a manual switch. The light emitting diode control circuit according to claim 1, wherein one end of the light emitting diode is connected to a transformer circuit. The light emitting diode control circuit according to claim 1, wherein a constant current source is connected between the transformer circuit and the light emitting diode. 2. The light emitting diode control circuit according to claim 1, wherein there are three light emitting diodes, and the three light emitting diodes can emit red, green, and blue, respectively.

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