TWI458387B - Illumination driver circuit - Google Patents

Description

Lighting drive circuit

The present invention relates to a lighting device, and more particularly to an illumination driving circuit on a lighting device.

In recent years, with the development of optoelectronic technology, many novel lighting devices have been developed in the industry. Among them, Light-Emitting Diode (LED) lamps have received extensive attention. The luminous efficiency of the LED lamp is superior to that of the traditional incandescent bulb, because the waste heat generated by the LED is far higher than other types of lamps, which is in line with the energy saving trend.

Conventional incandescent bulbs are often used with TRIAC dimmers for resistive loads, allowing users to adjust the required brightness to avoid wasting power. In general, the control dimmer includes a variable resistor, and the user can adjust the resistance of the variable resistor to form a different conduction angle of the dimming dimmer, thereby changing the output waveform and achieving the dimming effect.

At present, the conventional control dimmer is mainly suitable for the dimming application of a resistive load (such as a conventional bulb), and the dimming control is easy to dim the conventional conventional bulb (such as an incandescent bulb). However, the control dimmer is not directly applicable to the LED lamp. Since the characteristics of the LED lamp are not purely resistive loads, it is necessary to overcome some technical problems when dimming the LED lamp with a dimming control dimmer.

Since the LED lamp is not a purely resistive load, it has a considerable impedance before it is turned on. Under the effect of non-conducting, conducting or low-voltage operation, it is affected by the leakage current of the dimming control dimmer, and the LED lamp will be Produces flicker or instability. Especially when using a general-purpose LED driver controller on the market, the above-mentioned flicker and instability will be particularly serious. In order to cope with the trend of energy saving and the needs of users, it is necessary to develop LED lighting equipment and its driving circuit that can be used with the control dimmer.

In order to solve the above problems, the present invention provides an illumination driving circuit having a two-stage blood squirting circuit coupled between an alternating current input and a non-resistive illuminating load. One of the stages is a fixed blood-splitting circuit, which continuously draws a continuous blood-splitting current from the anode side of the non-resistive illuminating load to prevent accumulation of electric charge on the anode side of the illuminating load to form a cumulative voltage, resulting in a capacitor in the 调 control dimmer Unable to charge and discharge smoothly. The other stage is a pulse bleed circuit, which is used to generate an instantaneous pulse bleed current when the non-resistive illuminating load is initially activated, which is a transient large current to ensure stable conduction of the 矽 control dimmer. According to the above two-stage bloodletting circuit, the continuous blood-splitting current can be used to make the non-resistive illuminating load have a characteristic similar to a general resistive load, and the pulse bleeder current can be used to ensure the conduction stability of the dimmer when starting.

One aspect of the present disclosure is to provide an illumination driving circuit coupled between an AC input and a non-resistive illumination load. The illumination drive circuit includes a dimming module, a rectifier module, a fixed bloodletting circuit, and a pulse. Bloodletting circuit. The dimming module is coupled to the AC input for generating a periodic driving signal, where the periodic driving signal includes a plurality of periodic driving pulse waves. The rectifier module is coupled to the dimming module and the non-resistive illuminating load The rectifier module rectifies the periodic driving signal and transmits it to one of the anode sides of the non-resistive lighting load. The fixed blood-splitting circuit is coupled to the rectifier module, and the fixed blood-splitting circuit is connected in parallel with the non-resistive light-emitting load. During the duration of the driving pulse waves, the fixed blood-splitting circuit continuously draws a continuous bloodletting from the anode side. Current. The pulse bleed circuit is coupled to the rectifier module, and the pulse bleed circuit is connected in parallel with the non-resistive illuminating load. At the triggering time of the driving pulse waves, the pulse bleeder circuit temporarily acquires one from the anode side. Pulsed blood flow current.

According to an embodiment of the present invention, the two ends of the fixed blood-splitting circuit are electrically connected to the anode side and the system ground end, and the continuous blood-sampling current is from the anode side through the fixed blood-splitting circuit during the duration of the driving pulse waves. Flow to the ground of the system.

According to an embodiment of the present invention, the two ends of the pulse blood-splitting circuit are electrically connected to the anode side and the system ground end, and at the triggering time point of the driving pulse waves, the pulse blood-sampling current is from the anode side via the pulse The bloodletting circuit flows to the ground of the system.

According to an embodiment of the invention, the fixed bloodletting circuit includes a first switch, a first resistor, a second resistor, and a first rectifying diode. The first switch has an input pole, an output pole, and a control pole coupled to the anode side. The first resistor is coupled between the anode side and the control electrode of the first switch. The second resistor is coupled between the output of the first switch and the ground of the system. The first rectifier diode is coupled between the gate of the first switch and the ground of the system.

According to an embodiment of the invention, the pulse bleed circuit comprises a second switch, a third resistor, and a capacitor. The second switch has an input pole, An output pole and a control pole coupled to the output pole of the first switch. The third resistor is coupled between the output of the first switch and the input of the second switch. The capacitor is coupled between the third resistor and the ground of the system.

According to another embodiment of the present invention, the pulse bleeder circuit includes a second switch, a third switch, a third resistor, a capacitor, a fourth resistor, and a second rectifying diode. The second switch has an input pole, an output pole, and a control pole. The third switch has an input pole, an output pole, and a control pole. The input pole of the third switch is coupled to the anode side, and the control pole of the second switch is coupled to the output pole of the third switch. The third resistor is coupled between the output of the third switch and the input of the second switch. The capacitor is coupled between the third resistor and the ground of the system. The fourth resistor is coupled between the anode side and the control electrode of the third switch. The second rectifier diode is coupled between the gate of the third switch and the ground of the system.

According to an embodiment of the present invention, the illumination driving circuit further includes a fourth switch coupled between the second resistor and the ground of the system, and the control electrode of the fourth switch is coupled to a gate driving signal, according to the The gate drive signal operates to switch whether the fixed bloodletting circuit draws the continuous blood discharge current.

According to an embodiment of the present invention, the fixed blood-splitting circuit further includes a fifth resistor, the fifth resistor and the second resistor are connected in series to form a voltage dividing circuit, and a voltage divider between the fifth resistor and the second resistor The node voltage is used as a pulse width modulation signal, and the pulse width modulation signal is used to control a dimming driving circuit of the non-resistive lighting load.

According to an embodiment of the invention, the illumination driving circuit further includes a resistor-capacitor filter coupled to the output terminal of the first switch and the ground of the system The resistor-capacitor filter is configured to generate an analog potential dimming signal, and the analog potential dimming signal is used to control a dimming driving circuit of the non-resistive lighting load.

According to an embodiment of the present invention, the dimming module includes a dimming control, and the periodic driving signal generated by the dimming module has different conduction angles according to different brightness of the illumination to be output, and the rectifying module A bridge rectifier is included for rectifying the periodic driving signal from an alternating signal to a direct current signal.

The present invention will be described with reference to the accompanying drawings and the detailed description of the present invention, which may be modified and modified by the teachings of the present invention without departing from the invention. Spirit and scope.

Referring to FIG. 1 and FIG. 2, FIG. 1 is a functional block diagram of an illumination driving circuit 100 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing waveforms of signals on the illumination driving circuit 100 according to an embodiment of the invention. As shown in FIG. 1 , the illumination driving circuit 100 is coupled between the AC input 200 and the non-resistive lighting load 220. In practical applications, the non-resistive lighting load 220 may be a light emitting diode or other equivalent. Light-emitting element. The AC input 200 provides an AC power signal AC.

The illumination driving circuit 100 includes a dimming module 120, a rectifying module 140, a fixed bloodletting circuit 160, and a pulse bleed circuit 180. The dimming module 120 is coupled to the AC input 200 for generating a periodic driving signal, and periodically The drive signal contains a plurality of periodic drive pulses.

The rectifying module 140 is coupled between the dimming module 120 and the non-resistive illuminating load 220. The rectifying module 140 rectifies the periodic driving signal generated by the dimming module 120, and rectifies the rectified periodic driving signal. V _{DC is} delivered to the anode side 220a of the non-resistive illuminating load 220.

The fixed bloodletting circuit 160 is coupled to the rectifier module 140, and the fixed bloodletting circuit 160 is connected in parallel with the non-resistive light-emitting load 220. During the duration of the driving pulse waves, the fixed blood-splitting circuit 160 continuously draws from the anode side 220a. The blood flow current I _H (as shown in Figure 2). In this embodiment, the two ends of the fixed bled circuit 160 are electrically connected to the anode side 220a and the system ground end 240. During the duration of the drive pulses in the rectified periodic drive signal V _DC , the continuous bleeder current I _H flows from the anode side 220a to the system ground terminal 240 via the fixed bleed circuit 160.

The pulse bleed circuit 180 is coupled to the rectifier module 140, and the pulse bleed circuit 180 is connected in parallel with the non-resistive illuminating load 220. The triggering time of the driving pulse waves in the rectified periodic driving signal V _DC (eg, 2nd) point of time T1 in FIG, T2, T3, T4), a pulse circuit 180 transitory bled from the anode side 220a draws the blood pulse current I _P (as shown in FIG. 2). In this embodiment, the two ends of the pulse bleed circuit 180 are electrically connected to the anode side 220a and the system ground terminal 240. At the triggering time of the driving pulse waves, the pulse bleed current I _P is pulsed from the anode side 220a via pulse bleed. Circuit 180 flows to system ground terminal 240.

The following paragraphs of the present invention provide a plurality of circuit embodiments that can be used to implement the functions and operations described above for the illumination driving circuit 100, but the present invention is not limited to the following circuit architecture.

Please refer to FIG. 3, which is a circuit diagram of a lighting driving circuit 100a according to a first embodiment of the present invention.

As shown in FIG. 3, the illumination driving circuit 100a of the first embodiment includes a dimming module 120, a rectifying module 140, a fixed bloodletting circuit 160, and a pulse bleed circuit 180.

In this example, the dimming module 120 includes a TRIAC dimmer. The periodic driving signals generated by the dimming module 120 have different conduction angles according to the brightness of the illumination to be output. The rectifier module 140 includes a bridge rectifier BD, and the rectifier module 140 is configured to rectify the periodic driving signal from the alternating signal to the direct current signal.

The fixed blood-splitting circuit 160 of the illumination driving circuit 100a includes a first switch S1, a first resistor R1, a second resistor R2, and a first rectifying diode Zd1. The first switch S1 has an input pole, an output pole and a control pole, and an input pole of the first switch S1 is coupled to the anode side 220a. The first resistor R1 is coupled between the anode side 220a and the control electrode of the first switch S1. The second resistor R2 is coupled between the output terminal of the first switch S1 and the system ground terminal 240. The first rectifier diode Zd1 is coupled between the gate of the first switch S1 and the system ground terminal 240.

During the duration of the drive pulse waves in the rectified periodic drive signal V _DC , the first switch S1 is turned on, and the fixed bled circuit 160 continuously draws the continuous discharge current I _H from the anode side 220a (as shown in FIG. 2 and 3 is shown flowing to the system ground terminal 240 via the first switch S1 and the second resistor R2. Among them, the continuous bleeder current I _H can be used to make the non-resistive illuminating load 220 have characteristics similar to a general resistive load, such as a resistive characteristic having a linear relationship between voltage and current.

In addition, the non-resistive illuminating load 220 (such as a light-emitting diode lamp) has a very high impedance before being turned on. This characteristic makes the load terminal (such as the anode side 220a) susceptible to a coupling voltage, and this coupling voltage will affect the control dimming. The capacitor C _{D in the device is} normally charged and discharged, causing the malfunctioning dimmer to operate abnormally, which may cause the non-resistive illuminating load 220 to be unlit. The fixed bleed circuit 160 can be used to eliminate the coupling voltage accumulated at the load end, so that the capacitor C _D can be normally charged and discharged.

As shown in FIG. 3, the pulse bleed circuit 180 includes a second switch S2, a third resistor R3, and a capacitor C. The second switch S2 has an input pole, an output pole and a control pole, and a control pole of the second switch S2 is coupled to the output pole of the first switch S1. The third resistor R3 is coupled between the output pole of the first switch S1 and the input pole of the second switch S2. The capacitor C is coupled between the third resistor R3 and the system ground terminal 240.

In this embodiment, the output of the first switch S1 generates a control signal V _LDO (please refer to FIG. 2 together) for controlling the gate of the second switch S2.

The triggering time point of the driving pulse waves in the rectified periodic driving signal V _DC (as time points T1, T2, T3, T4 in FIG. 2), the second switch S2 is turned on, and the pulse bleeder circuit 180 is transient. The pulse bleed current I _P (as shown in FIG. 2) is drawn from the anode side 220a through the third resistor R3 and the second switch S2 to the system ground terminal 240.

Thereafter, the capacitor C in the pulse bleed circuit 180 is charged with the pulse bleed current I _P , so that the input terminal of the second switch S2 rises (the voltage difference between the input terminal and the control terminal decreases), and then the second switch S2 is gradually turned off. And gradually reduce the magnitude of the current of the pulse bleed current I _P .

In this way, the pulse bleed circuit 180 composed of the resistor, the capacitor and the switching element generates a large pulse bleed current I _P at the triggering moment of the driving pulse wave, wherein the resistance of the third resistor R3 can be designed to be smaller than the second The resistance of the resistor R2 causes the pulse bleeder current I _{P to be} significantly larger than the continuous bleeder current I _H . When the pilot dimmer in the dimming module 120 is turned off (that is, during the driving pulse low level), it is reset by the transistor (ie, the second switch S2), so that the pulse can be normally operated in the next cycle. The bloodletting circuit 180 is used to ensure that the control dimmer in the dimming module 120 can be stably turned on.

In the illumination driving circuit 100a of the first embodiment shown in FIG. 3, the control electrode V _LDO is generated by the output terminal of the first switch S1 to control the control electrode of the second switch S2, but the present invention does not think that limit.

Please refer to FIG. 4, which is a circuit diagram of the illumination driving circuit 100b according to the second embodiment of the present invention. In the illumination driving circuit 100b, the pulse bleed circuit 180 includes a second switch S2, a third resistor R3, and a capacitor C. In addition, compared with the first embodiment, the pulse bleed circuit 180 further includes a third switch S3, a fourth resistor R4, and a second rectifying diode Zd2.

The second switch S2 has an input pole, an output pole, and a control pole. The third switch S3 has an input pole, an output pole and a control pole. The input pole of the third switch S3 is coupled to the anode side 220a, and the control pole of the second switch S2 is coupled to the output pole of the third switch S3. The third resistor R3 is coupled between the output terminal of the third switch S3 and the input terminal of the second switch S2. The capacitor C is coupled between the third resistor R3 and the system ground terminal 240. The fourth resistor R4 is coupled between the anode side 220a and the control electrode of the third switch S3. The second rectifying diode Zd2 is coupled between the control electrode of the third switch S3 and the system ground terminal 240.

The illumination driving circuit 100b in FIG. 4 is different from the embodiment of FIG. 3 in that the control signal V _LDO on the control electrode of the second switch S2 is the third switch S3 and the fourth resistor R4 of the pulse bloodletting circuit 180 itself. The second rectifier diode Zd2 is generated without being integrated with the fixed bloodletting circuit 160. In addition, other circuit architectures and actuation principles are substantially similar to those of the first embodiment described above.

Moreover, as the fixed bleed circuit 160 will result in sustained power consumption, the present invention further discloses embodiments that reduce the power consumption of the fixed bleed circuit 160. Please refer to FIG. 5, which is a circuit diagram of a lighting driving circuit 100c according to a third embodiment of the present invention. The illumination driving circuit 100c in the third embodiment can be used in conjunction with a switching type light emitting diode driver.

In the third embodiment, the illumination driving circuit 100c further includes a fourth switch S4, the fourth switch S4 is coupled between the second resistor R2 and the system ground terminal 240, and the fourth switch S4. The control electrode is coupled to the gate driver signal GDRV, and the fourth switch S4 switches according to the operation of the gate drive signal GDRV to switch whether the fixed bloodletting circuit 160 draws the continuous blood discharge current I _H .

When the illumination driving circuit 100 in the present case is used with the switching type LED driver, the operation of the fixed bloodletting circuit 160 can be controlled by the gate driver in the LED driver, thereby reducing the power consumption. .

In another aspect, the present invention further discloses an embodiment of generating a pulse width modulation (PWM) signal using the two-stage bloodletting line of the present invention. Please refer to FIG. 6 , which is a circuit diagram of the illumination driving circuit 100 d according to the fourth embodiment of the present invention.

In the fourth embodiment, the illumination driving circuit 100d further includes a fifth resistor R5, the fifth resistor R5 and the second resistor R2 are connected in series to form a voltage dividing circuit, and the fifth resistor R5 and the second. The voltage dividing node voltage V _PWM between the resistors R2 is used as a pulse width modulation signal, and the pulse width modulation signal is used to control the dimming driving circuit (not shown) of the non-resistive lighting load 220 or to supply pulse width modulation. Other dimming circuits for signals.

In addition, please refer to FIG. 7 , which is a circuit diagram of the illumination driving circuit 100 e according to the fifth embodiment of the present invention. The illuminating capacitor circuit 190 of the fifth embodiment further includes a RC filter 190 coupled between the output terminal of the first switch S1 and the system ground terminal 240, and the RC filter. The 190 is used to generate the analog potential dimming signal ADIM, and the analog potential dimming signal ADIM is used to control the dimming driving circuit (not shown) of the non-resistive lighting load 220. Thereby, the desired analog dimming potential can be obtained through the resistor-capacitor filter 190. Moreover, the resistor-capacitor value design can effectively solve the voltage mismatch generated by the bridge-type rectification of the periodic driving signal V _DC generated by the dimming module 120.

Compared with the prior art, the present invention provides an illumination driving circuit having a two-stage blood-splitting circuit coupled between an alternating current input and a non-resistive light-emitting load. One of the stages is a fixed blood-splitting circuit, which continuously draws a continuous blood-splitting current from the anode side of the non-resistive illuminating load to prevent accumulation of electric charge on the anode side of the illuminating load to form a cumulative voltage, resulting in a capacitor in the 调 control dimmer Unable to charge and discharge smoothly. The other stage is a pulse bleed circuit, which is used to generate an instantaneous pulse bleed current when the non-resistive illuminating load is initially activated, which is a transient large current to ensure 矽 control The light device can be stably turned on. According to the above two-stage bloodletting circuit, the continuous blood-splitting current can be used to make the non-resistive illuminating load have a characteristic similar to a general resistive load, and the pulse bleeder current can be used to ensure the conduction stability of the dimmer when starting.

While the present invention has been described above in terms of several embodiments, it is not intended to limit the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

100, 100a, 100b, 100c, 100d, 100e‧‧‧ illumination drive circuit

120‧‧‧ dimming module

140‧‧‧Rectifier Module

160‧‧‧Fixed bloodletting circuit

180‧‧‧pulse bloodletting circuit

190‧‧‧resistive capacitor filter

200‧‧‧AC input

220‧‧‧ non-resistive luminous load

220a‧‧‧Anode side

240‧‧‧System ground

AC‧‧‧AC power signal

V _DC ‧‧‧Rectified periodic drive signal

I _H ‧‧‧Continuous bloodletting current

I _P ‧‧‧pulse bloodletting current

The above and other objects, features, advantages and embodiments of the present invention will become more apparent and understood. 2 is a schematic diagram showing waveforms of respective signals on an illumination driving circuit according to an embodiment of the present invention; FIG. 3 is a circuit diagram of a lighting driving circuit according to a first embodiment of the present invention; 4 is a circuit architecture diagram of a lighting driving circuit according to a second embodiment of the present invention; FIG. 5 is a circuit diagram of a lighting driving circuit according to a third embodiment of the present invention; A circuit architecture diagram of a lighting driving circuit according to a fourth embodiment of the present invention is shown; and FIG. 7 illustrates a lighting driver according to a fifth embodiment of the present invention. Circuit diagram of the dynamic circuit.

100‧‧‧Lighting drive circuit

120‧‧‧ dimming module

140‧‧‧Rectifier Module

160‧‧‧Fixed bloodletting circuit

180‧‧‧pulse bloodletting circuit

200‧‧‧AC input

220‧‧‧ non-resistive luminous load

220a‧‧‧Anode side

240‧‧‧System ground

AC‧‧‧AC power signal

V _DC ‧‧‧Rectified periodic drive signal

I _H ‧‧‧Continuous bloodletting current

I _P ‧‧‧pulse bloodletting current

Claims (10)

An illumination driving circuit is coupled between an AC input and a non-resistive light-emitting load. The illumination driving circuit includes: a dimming module coupled to the AC input for generating a periodic driving signal. The periodic driving signal includes a plurality of periodic driving pulse waves; a rectifying module is coupled between the dimming module and the non-resistive lighting load, and the rectifying module rectifies and transmits the periodic driving signal Up to one anode side of the non-resistive illuminating load; a fixed bleed circuit coupled to the rectifying module, and the fixed bleed circuit is connected in parallel with the non-resistive illuminating load, during the duration of the driving pulse waves, the fixing The bloodletting circuit continuously draws a continuous blood discharge current from the anode side; and a pulse bloodletting circuit coupled to the rectifier module, and the pulse bloodletting circuit is connected in parallel with the non-resistive light emitting load to trigger the driving pulse waves At the time point, the pulse bleed circuit transiently draws a pulse of bleed current from the anode side. The illumination driving circuit of claim 1, wherein both ends of the fixed blood-splitting circuit are electrically connected to the anode side and a system ground end, and the continuous blood-sampling current is from the anode side during the duration of the driving pulse waves. The fixed bloodletting circuit flows to the ground of the system. The illumination driving circuit of claim 1, wherein the pulse is bled The two ends of the circuit are electrically connected to the anode side and a system ground end. At the triggering time point of the driving pulse waves, the pulse bleed current flows from the anode side to the system ground via the pulse bleed circuit. The illumination driving circuit of claim 1, wherein the fixed bleed circuit comprises: a first switch having an input pole, an output pole and a control pole, the input pole being coupled to the anode side; a first resistor The second resistor is coupled between the output end of the first switch and a system ground; and a first rectifying diode is coupled to the anode and the control electrode of the first switch; The control pole of the first switch is coupled to the ground of the system. The illumination driving circuit of claim 4, wherein the pulse bleeder circuit comprises: a second switch having an input pole, an output pole and a control pole, the control pole being coupled to the output pole of the first switch; a third resistor coupled between the output of the first switch and the input of the second switch; and a capacitor coupled between the third resistor and the ground of the system. The illumination driving circuit of claim 4, wherein the pulse is bled The circuit includes: a second switch having an input pole, an output pole, and a control pole; a third switch having an input pole, an output pole, and a control pole, the input pole of the third switch being coupled to the On the anode side, the control electrode of the second switch is coupled to the output terminal of the third switch; a third resistor is coupled between the output terminal of the third switch and the input terminal of the second switch; The second resistor is coupled between the anode and the control terminal of the third switch; and a second rectifier diode coupled to the third resistor The control pole of the third switch is between the ground of the system. The illumination driving circuit of claim 4, further comprising a fourth switch coupled between the second resistor and the ground of the system, the control electrode of the fourth switch being coupled to a gate driving signal, according to The operation of the gate drive signal further switches whether the fixed bloodletting circuit draws the continuous blood discharge current. The illumination driving circuit of claim 4, wherein the fixed blood-splitting circuit further comprises a fifth resistor, the fifth resistor and the second resistor are connected in series to form a voltage dividing circuit, the fifth resistor and the second resistor The voltage divider voltage is used as a pulse width modulation signal, and the pulse width modulation signal is used to control a dimming driving circuit of the non-resistive lighting load. The illumination driving circuit of claim 4, further comprising a resistor-capacitor filter coupled between the output of the first switch and the ground of the system, wherein the resistor-capacitor filter generates a type of potential dimming signal The analog potential dimming signal is used to control a dimming driving circuit of the non-resistive lighting load. The illumination driving circuit of claim 1, wherein the dimming module comprises a dimming control, and the periodic driving signal generated by the dimming module has different conduction according to different brightness of the illumination to be outputted. The rectifier module includes a bridge rectifier for rectifying the periodic driving signal from an alternating current signal to a direct current signal.