TWI434613B - Driver for an adjustable light emitting diode - Google Patents

Description

Adjustable light-emitting diode (LED) driver

The invention relates to a driver, and more particularly to a driver of an adjustable light emitting diode (LED).

Light-emitting diodes are often used as indicators, display panels, etc. at the beginning; they are also used as illumination with the appearance of white light-emitting diodes. The light-emitting diode is a new type of light source, which has the advantages of high efficiency, long life, and is not easily damaged, and the conventional light source cannot be compared with it. However, when the light-emitting diode is used as a lighting device, it can only be turned on and off. However, the adjustment of the illumination brightness cannot be performed, thereby highlighting the defect that the light-emitting diode is insufficient in practical use as a lighting device.

To this end, a general light-emitting diode is electrically connected to a dimming unit (ie, an AC dimmer), and the illumination brightness of the LED is adjusted by the dimming unit. However, the dimming unit is only applicable. In the case of a general light bulb, once used for the light emitting diode, the light emitting diode cannot be controlled by the existing dimming unit, and can only be turned on and off because the dimming unit has a minimum holding current limit. When the minimum operating current is less than the minimum holding current, the dimming unit will be turned off or restarted, so when the output power becomes small (ie, the brightness of the LED illumination becomes dark), flashing or extinction will occur. The unstable condition is that the LED emits an abnormal condition such as flashing or extinction during the adjustment process, which not only causes the user's eye discomfort, but also reduces the life of the LED.

Therefore, how to develop a driver of an adjustable light-emitting diode (LED) can solve the above problem, that is, the motivation of the invention.

An object of the present invention is to provide a driver for an adjustable light-emitting diode (LED). When the driver adjusts the illumination brightness of the light-emitting diode, abnormal conditions such as flashing or extinction are avoided, thereby preventing the user from being prevented. Eye discomfort and increased life of the light-emitting diode.

In order to achieve the foregoing objective, an adjustable light-emitting diode (LED) driver according to the present invention is electrically connected between the light-emitting diode and an alternating current power source, and the light-emitting diode is electrically connected. There is a variable voltage driving unit, the AC power source is electrically connected to a dimming unit and a transformer rectifying unit, and the driver comprises: a detecting unit electrically connected to the variable voltage rectifying unit for detecting whether the AC power source passes The adjustment of the dimming unit and the operating current of the dimming unit are minimum operating currents. When the AC power source is adjusted by the dimming unit, a driving signal is output, when the operating current of the dimming unit is minimum. When the current is current, a start signal is output, and vice versa, a turn-off signal is output; an adjusting unit is electrically connected to the detecting unit, and the adjusting unit receives the driving signal and outputs a dimming signal after the operation, and the adjusting unit receives the signal. After the start signal, a start control signal is output, and the adjusting unit outputs a turn-off start signal after receiving the turn-off signal; a pulse width modulation (P) a signal modulation unit electrically connected to the adjustment unit, the pulse width modulation (PWM) signal modulation unit receives the dimming signal and mixes and modulates the pulse width modulation signal according to a certain ratio, and outputs one An identification signal; a pulse width modulation (PWM) control unit electrically connected between the pulse width modulation (PWM) signal modulation unit and the variable voltage drive unit, the pulse width modulation (PWM) control unit receiving The identification signal is used to limit the output power of the variable voltage driving unit; an AC load unit is electrically connected to the adjusting unit, and the AC load unit receives the starting control signal, and provides a current to the dimming And receiving, by the unit, the shutdown load signal, stopping supplying current to the dimming unit.

Preferably, when the AC power source is adjusted by the dimming unit, the dimming unit outputs a conduction phase angle compensation delay signal to the detecting unit, and the detecting unit calculates a corresponding conduction phase angle compensation delay and converts Into the drive signal.

Preferably, when the adjusting unit receives the driving signal and calculates the magnitude of the complementary phase angle, a corresponding dimming signal is output.

Preferably, when the detecting unit does not detect the adjustment of the AC power source through the dimming unit, a hold signal is output to the adjusting unit.

The present invention has been described in connection with the preferred embodiments of the present invention in accordance with the accompanying drawings.

Referring to FIG. 1 and FIG. 2, a driver of an adjustable light-emitting diode (LED) is provided between the light-emitting diode 11 and the AC power source 12, and the light-emitting diode 11 is electrically connected. Electrically connected to a variable voltage drive unit 13 , the AC power supply 12 is electrically connected to a dimming unit 14 A transformer rectifier unit 15 is mainly composed of a detecting unit 20, an adjusting unit 30, a pulse width modulation (PWM) signal modulating unit 40, a pulse width modulation (PWM) control unit 50, and an AC load. The unit 60 is composed of an AC AC phase angle detecting module electrically connected to the transformer unit 15 for detecting whether the AC power source 12 passes the adjustment of the dimming unit 14 and the adjustment. Whether the operating current of the light unit 14 is the minimum operating current. When the detecting unit 20 detects the adjustment of the alternating current power source 12 through the dimming unit 14, it outputs a driving signal, and vice versa, outputs a holding signal, wherein the detecting unit outputs a holding signal. 20, when detecting the adjustment of the AC power source 12 through the dimming unit 14, the dimming unit 14 outputs a conduction phase angle compensation delay signal to the detecting unit 20, and the detecting unit 20 calculates a corresponding conduction phase angle compensation. Deferred and converted into the driving signal; when the detecting unit 20 detects that the operating current of the dimming unit 14 is the minimum operating current, a start signal is output, and a turn-off signal is output.

The adjusting unit 30 is electrically connected to the detecting unit 20, and when the adjusting unit 30 receives the driving signal of the detecting unit 20, calculates a magnitude of the complementary phase angle, and outputs a corresponding dimming signal; The receiving signal of the detecting unit 20 does not perform any action; the adjusting unit 30 outputs a start control signal after receiving the start signal, and the adjusting unit 30 outputs a turn-off start signal after receiving the turn-off signal.

The pulse width modulation (PWM) signal modulating unit 40 is electrically connected to the tone The node unit 30, after receiving the dimming signal of the adjusting unit 30, the pulse width modulation (PWM) signal modulating unit 40 performs mixed modulation with the pulse width modulation signal according to a certain ratio, and outputs an identification signal.

The pulse width modulation (PWM) control unit 50 is electrically connected between the pulse width modulation (PWM) signal modulation unit 40 and the variable voltage driving unit 13, and the pulse width modulation (PWM) control unit 50 receives After the identification signal of the pulse width modulation (PWM) signal modulating unit 40 is reached, the output power of the variable voltage driving unit 13 is limited to adjust the illumination brightness of the light emitting diode 11.

The AC load unit 60 is electrically connected to the adjustment unit 30. When the AC load unit 60 receives the start control signal of the adjustment unit 30, a current is supplied to the dimming unit 14 to maintain the dimming unit 14. Normal operation; when the AC load unit 60 receives the shutdown start signal of the adjustment unit 30, the supply of current to the dimming unit 14 is stopped.

The above is the main constituent unit of the embodiment of the present invention and its configuration description.

The mode of operation and the effect of the embodiment of the present invention are described below. Please refer to FIG. 2 for details.

When AC power is input from both ends of L and N in FIG. 2, it is rectified into a high-voltage DC power by the fuse 71, the dimming unit 14, the EMI filter circuit 72, and the transformer rectifier unit 15. The detection unit 20 is introduced through the resistors 73, 74 to detect whether the input AC has undergone adjustment by the dimming unit 14, and if not, a hold signal is issued to the adjustment unit 30 without performing any action.

When the detecting unit 20 detects that the user performs dimming operation on the dimming unit 14, the dimming unit 14 outputs a conduction phase angle compensation delay signal to the detecting unit 20, and the detecting unit 20 calculates corresponding The conduction phase angle compensation is delayed and converted into a driving signal, and the driving signal is transmitted to the adjusting unit 30, and the adjusting unit 30 calculates the magnitude of the complementary phase angle to be converted into a corresponding dimming signal size and sends the pulse width modulation to the pulse width adjustment. a PWM signal modulation unit 40, the pulse width modulation (PWM) signal modulation unit 40 mixes and modulates the dimming signal together with the pulse width modulation signal according to a certain ratio, and outputs an identification signal to the pulse The variable width modulation (PWM) control unit 50, the pulse width modulation (PWM) control unit 50 limits the output power of the variable voltage driving unit 13, and the light emitting diode 11 is a fixed voltage when it is used. When the output power changes, the voltage does not change, the current must decrease, and the current decreases. The illuminance of the light-emitting diode 11 changes in proportion to the magnitude of the current, so that the light-emitting diode 11 can be adjusted. Illumination.

In addition, when the dimming unit 14 receives the activation control signal of the adjustment unit 30 during the adjustment process, a current is supplied to the dimming unit 14 to maintain the dimming unit 14 to work normally. The light-emitting diode 11 will work normally when it is darkened.

Therefore, in addition to adjusting the illumination brightness of the LED 11 by the electrical connection of the driver, it is possible to avoid an abnormal situation such as flashing or extinction, thereby preventing the user from discomfort and increasing the brightness. The purpose of the life of the light-emitting diode 11 is.

In addition, the driver of the present invention can share the traditional AC dimmer, and the dimmer is not replaced when the LED is replaced, thereby saving unnecessary loss and achieving real energy saving.

In the above, the embodiments and the drawings are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equal changes and modifications made by the scope of the patent application of the present invention should be It is within the scope of the patent of the present invention.

11. . . Light-emitting diode

12. . . AC power

13. . . Transformer drive unit

14. . . Dimming unit

15. . . Transformer rectifier unit

20. . . Detection unit

30. . . Adjustment unit

40. . . Pulse width modulation (PWM) signal modulation unit

50. . . Pulse width modulation (PWM) control unit

60. . . AC load unit

71. . . fuse

72. . . EMI filter circuit

73. . . resistance

Figure 1 is a block diagram of the present invention.

Figure 2 is a schematic diagram of a circuit diagram of the present invention.

11. . . Light-emitting diode

12. . . AC power

13. . . Transformer drive unit

14. . . Dimming unit

15. . . Transformer rectifier unit

20. . . Detection unit

30. . . Adjustment unit

40. . . Pulse width modulation (PWM) signal modulation unit

50. . . Pulse width modulation (PWM) control unit

60. . . AC load unit

Claims (4)

The utility model relates to an adjustable light-emitting diode (LED) driver, which is electrically connected between the light-emitting diode and an alternating current power source, wherein the light-emitting diode is electrically connected to a variable-voltage driving unit, and the alternating current power source is electrically connected The light unit and a transformer rectifier unit, the driver includes: a detecting unit electrically connected to the transformer unit, configured to detect whether the AC power source passes the adjustment of the dimming unit and the operating current of the dimming unit Whether it is the minimum working current, when the AC power supply passes the adjustment of the dimming unit, a driving signal is output, and when the operating current of the dimming unit is the minimum working current, a start signal is output, otherwise the output is turned off. a signal, an adjusting unit electrically connected to the detecting unit, the adjusting unit receiving the driving signal and outputting a dimming signal after the operation, the adjusting unit receiving the start signal and outputting a start control signal, the adjusting unit receiving Outputting a turn-off enable signal after the off signal; a pulse width modulation (PWM) signal modulation unit electrically connected to the adjustment unit, the pulse The wide modulation (PWM) signal modulation unit receives the dimming signal and mixes and modulates the pulse width modulation signal according to a certain ratio, and outputs an identification signal; a pulse width modulation (PWM) control unit, which is electrically Between the pulse width modulation (PWM) signal modulation unit and the variable voltage driving unit, the pulse width modulation (PWM) control unit receives the identification signal to limit the output power of the variable voltage driving unit. An AC load unit electrically connected to the adjustment unit, the AC load unit receiving the start control signal, and providing a current to the dimming unit, the intersection When the flow load unit receives the shutdown enable signal, the supply of current to the dimming unit is stopped. The driver of the adjustable light-emitting diode (LED) according to claim 1, wherein the dimming unit outputs a conduction phase angle compensation delay signal when the AC power source is adjusted by the dimming unit. The detecting unit calculates the corresponding conduction phase angle compensation delay and converts into the driving signal. The driver of the adjustable light-emitting diode (LED) according to claim 1, wherein the adjusting unit outputs a corresponding dimming signal after receiving the driving signal to calculate a complementary phase angle. The actuator of the adjustable light-emitting diode (LED) according to claim 1, wherein when the detecting unit does not detect the adjustment of the alternating current power source through the dimming unit, a hold signal is output to the adjusting unit.