TWI496505B - Light emitting device control circuit and hot-swapping detection circuit thereof and light emitting device circuit therefor - Google Patents

Description

Light-emitting element control circuit and hot plug sensing circuit and related Optical component circuit

The invention relates to a light-emitting element control circuit and a hot-swap sensing circuit thereof and related light-emitting element circuit, in particular to a light-emitting element control circuit with hot-swapping protection function and hot plug sensing thereof Circuit and related light-emitting element circuits.

1 shows a schematic diagram of a prior art light emitting diode (LED) power control circuit 100. As shown in FIG. 1, the LED power control circuit 100 is used to control the LED circuit 10. The LED power control circuit 100 includes a light-emitting element control circuit 110, a power stage circuit 120, and a feedback circuit 130. The light-emitting element control circuit 110 is connected to the feedback circuit 130 to receive the feedback signal FB, and generates a control signal GATE for operating the power switch in the power stage circuit 120, thereby converting the input voltage Vin into an output voltage Vout. An output current Iout is supplied to be supplied to the LED circuit 10. The power stage circuit 120 can be a synchronous or asynchronous step-down, step-up, back-pressure, buck-boost, or step-up power stage circuit, as shown in Figures 2A-2J.

In general, the LED power control circuit 100 adjusts the output current Iout to a fixed preset current during normal operation, and suddenly shifts the LED circuit 10 before the LED power control circuit 100 is stopped, that is, in the normal operation mode. In addition, the light-emitting element control circuit 110 is continuously operated to attempt to adjust the output current Iout to a preset current. This results in wasted power in the operation of the circuit. The LED circuit 10 is then suddenly replaced, and at a relatively high output voltage Vout, this produces an instantaneous surge current. Instantaneous inrush current can cause damage to components in the circuit and reduce the life of the circuit. In addition, if the LED circuit 10 is suddenly removed, there is no voltage drop protection between the output terminal and the input terminal, such as short circuit between the output terminal and the input terminal due to human contact, which is dangerous. Therefore, in the case where the LED circuit 10 is removed, the output voltage Vout must be controlled below the safety limit.

In view of the above, the present invention is directed to the deficiencies of the prior art described above, and provides a light-emitting element control circuit having a hot-swap protection function and a hot-swap sensing circuit and associated light-emitting element circuit therein.

In one aspect, the present invention provides a light-emitting element control circuit for generating a control signal to operate a power stage circuit in a normal mode of operation and converting an input voltage to an output voltage to supply a Outputting current to a light-emitting element circuit, the light-emitting element control circuit comprising: a hot-plug sensing circuit for generating a hot-plug determination signal according to the output voltage, so that the light-emitting element circuit is connected to the power stage circuit After being removed in the coupled state, and after reinstalling the light-emitting element circuit, the hot-plug determination signal is adjusted to determine that the light-emitting element control circuit operates in a certain voltage control mode or the normal operation. a mode, the hot plug sensing circuit includes: a sensing circuit for generating a sensing signal according to the output voltage; and a determining circuit coupled to the sensing circuit for detecting the signal according to the sensing signal And generating the hot plug determination signal; and a control signal generating circuit coupled to the power stage circuit and the hot plug sensing circuit respectively for Adjusting the control signal according to the hot plug determination signal, so that when the light emitting element circuit is removed in the normal operation mode, operating in the constant voltage control mode, and adjusting the output voltage to a preset level, And when the light-emitting element circuit is in a state of being coupled to the power stage circuit, operating in the normal operation mode.

In another aspect, the present invention provides a hot plug sensing circuit for use in a lighting element control circuit that generates a control signal to operate a power stage circuit in a normal operating mode. An input voltage is converted into an output voltage to supply an output current to a light-emitting element circuit, wherein the hot-swap sensing circuit is configured to generate a hot-plug determination signal according to the output voltage, so that the light-emitting element circuit is After being removed from the power level circuit, and after reinstalling the light-emitting element circuit, the hot-plug determination signal is adjusted to determine that the light-emitting element control circuit operates at a certain voltage control The mode or the normal operation mode, the hot plug sensing circuit includes: a sensing circuit for generating a sensing signal according to the output voltage; and a determining circuit coupled to the sensing circuit for The sensing signal generates the hot plug determination signal; wherein the sensing circuit comprises: a voltage dividing circuit for generating the current voltage according to the output voltage And a mode locking circuit coupled to the voltage dividing circuit and the determining circuit, respectively, for removing the light emitting element circuit after being coupled to the power level circuit, and in the light emitting Before the component circuit is reinstalled, the sensing signal is locked, thereby locking the light-emitting component control circuit to operate in the constant voltage control mode; and after the light-emitting component circuit is removed and reinstalled, the light-emitting component circuit is Before the power stage circuit is coupled, the sensing signal is locked, and the light-emitting element control circuit is locked to operate in the normal operation mode.

In a preferred embodiment, the light-emitting element circuit preferably includes: at least one light-emitting element coupled to the power stage circuit, and receiving the output voltage in the normal operation mode; and a resistance setting The circuit is coupled to the light emitting device, and configured to be coupled to the sensing circuit to adjust the sensing signal to adjust the hot plug after the light emitting device circuit is restored to the state coupled to the power stage circuit. The signal is determined such that the control signal generating circuit operates in the normal operating mode after the light-emitting element circuit is restored to the state coupled to the power stage circuit.

In a preferred embodiment, the mode locking circuit preferably includes: An auxiliary voltage dividing circuit coupled to the voltage dividing circuit; and a conduction control circuit coupled to the determining circuit and the auxiliary voltage dividing circuit, the conduction control circuit being controlled by the hot plugging determination signal, and Determining whether the auxiliary voltage dividing circuit is turned on, wherein when the auxiliary voltage dividing circuit is turned on, the voltage dividing circuit and the auxiliary voltage dividing circuit jointly determine a sensing signal, and when the auxiliary voltage dividing circuit is not turned on The sensing signal is separately determined by the voltage dividing circuit.

In a preferred embodiment, the hot plug sensing circuit and the control signal generating circuit have different operating low voltages, and the determining circuit includes: a comparing circuit coupled to the sensing circuit for sensing according to the sensing The signal and a reference signal generate a comparison result signal; and an optocoupler circuit coupled to the comparison circuit for generating the hot plug determination signal according to the comparison result signal.

In a preferred embodiment, the light-emitting element control circuit further includes a high-resistance circuit coupled between the input voltage and the output voltage, and the light-emitting element circuit is uncoupled from the power stage circuit. When the power switch is not turned on, the input voltage is converted into the output voltage.

In another aspect, the present invention provides a light-emitting element circuit that is hot-swappable and coupled to an output voltage, the light-emitting element circuit is controlled by a light-emitting element control circuit, and the light-emitting element control circuit is based on the light-emitting element circuit. Whether it is coupled to the output voltage and determines to operate in a certain voltage control mode or the normal operation mode, the light-emitting element circuit includes: a plurality of light-emitting elements coupled to the output voltage; and a resistance setting circuit, and the plurality The light-emitting element is coupled to determine the output voltage according to a current flowing through the light-emitting element circuit when the light-emitting element circuit is coupled to the output voltage, wherein when the light-emitting element circuit is coupled to the output voltage, When the light emitting element circuit is not coupled to the output voltage, the output voltage is a different value.

The purpose, technical content, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments.

10‧‧‧LED circuit

100,200‧‧‧LED power control circuit

110,210‧‧‧Lighting element control circuit

111‧‧‧ resistance setting circuit

120,220‧‧‧Power level circuit

130,230‧‧‧Responsive circuit

210‧‧‧Lighting element control circuit

211‧‧‧Hot-plug sensing circuit

212‧‧‧Control signal generation circuit

213‧‧‧High resistance circuit

2111‧‧‧Sensor circuit

2111a‧‧‧voltage circuit

2111b‧‧‧Mode Locking Circuit

2111c‧‧‧ conduction control circuit

2111d‧‧‧Auxiliary voltage divider circuit

2112‧‧‧Judgement circuit

2112a‧‧‧Comparative circuit

2112b‧‧‧Optical coupling circuit

2112a‧‧‧Comparative circuit

FB‧‧‧ feedback signal

GATE‧‧‧ control signal

Iout‧‧‧Output current

Vin‧‧‧Input voltage

Vout‧‧‧ output voltage

Figure 1 shows a schematic diagram of a prior art LED power control circuit 100.

Figure 2A-2J shows a synchronous or asynchronous step-down, step-up, back-pressure, buck-boost, or step-up power stage circuit.

Figures 3A and 3B show a first embodiment of the present invention.

Figure 4 shows a second embodiment of the invention.

Fig. 5 shows a third embodiment of the present invention.

Fig. 6 shows a fourth embodiment of the present invention.

Figures 7A-7D show fifth to eighth embodiments of the present invention.

Figure 8 shows a ninth embodiment of the invention.

Figure 9 shows a tenth embodiment of the present invention.

Fig. 10 is a view showing waveforms of respective signals in the foregoing embodiments.

Referring to Figures 3A and 3B, a first embodiment of the present invention is shown. As shown in FIG. 3A, the light-emitting element power supply control circuit 200 includes a light-emitting element control circuit 210, a power stage circuit 220, and a feedback circuit 230. In the normal operation mode, the light-emitting element control circuit 210 generates a control signal according to the feedback signal FB to operate at least one power switch in the power stage circuit 220 (not shown, see FIG. 2A-2J), and then input The voltage Vin is converted into an output voltage Vout to be supplied to the light-emitting element circuit 11. The power stage circuit 220 is, for example but not limited to, a power stage circuit as shown in FIG. 2A-2J, and may also be a power stage circuit 120 as shown in FIG. 1 , such as the power stage circuit shown in FIG. 1 . 120, the connection mode of the light-emitting element circuit 11 should be matched. Light-emitting element circuit 11 for example but not The LED circuit 10 shown in FIG. 1 may be limited to a single LED string, or may be an LED array composed of a plurality of parallel LED strings. The feedback signal FB is generated, for example, but not limited to, by the feedback circuit 230. The light emitting element control circuit 210 includes a hot plug sensing circuit 211 and a control signal generating circuit 212. The hot plug sensing circuit 211 is configured to generate a hot plug determination signal according to the output voltage Vout. After the light-emitting element circuit 11 is removed by being coupled to the power stage circuit 220, and after the light-emitting element circuit 11 is removed, the hot-swap sensing circuit 211 adjusts the hot-plug determination signal. It is determined that the light-emitting element control circuit 210 operates in a constant voltage control mode or the aforementioned normal operation mode. As shown in FIG. 3B, the hot plug sensing circuit 210 includes a sensing circuit 2111 and a determining circuit 2112. The sensing circuit 2111 is configured to generate a sensing signal according to the output voltage Vout. The determining circuit 2112 is coupled to the sensing circuit 2111 for generating a hot plug determination signal according to the sensing signal. The control signal generating circuit 212 is coupled to the power stage circuit 220 and the hot plug sensing circuit 211, respectively, for adjusting the control signal according to the hot plug determination signal, so that when the light emitting element circuit 11 is removed in the normal operation mode, Operating in a constant voltage control mode, and adjusting the output voltage Vout to a preset level, which is preferably lower than the level of the output voltage Vout in the normal operation mode, and when the light-emitting element circuit 11 is responsive to the power level After the condition of the circuit coupling, the reply operates in the normal operating mode. The so-called normal operating mode is, for example but not limited to, regulating the output current Iout to a fixed preset current.

Figure 4 shows a second embodiment of the invention. This embodiment shows a more specific embodiment of the hot plug sensing circuit 211 in the first embodiment. As shown in FIG. 4, the hot plug sensing circuit 211 includes a sensing circuit 2111 and a determining circuit 2112. The sensing circuit 2111 includes a voltage dividing circuit 2111a and a mode locking circuit 2111b. The voltage dividing circuit 2111a is configured to generate a sensing signal according to the output voltage Vout. For example, but not limited to, the voltage dividing circuit 2111a obtains a partial voltage of the output voltage Vout as a sensing signal. The mode locking circuit 2111b is coupled to the voltage dividing circuit 2111a and the determining circuit 2112, respectively, for removing the light emitting element circuit 11 after being coupled to the power stage circuit 220, and then in the light emitting element circuit 11 Prior to reinstallation, the sense signal is locked, thereby locking the light-emitting element control circuit 210 to operate in a constant voltage control mode. After the re-installation of the light-emitting element circuit 11 is removed, before the light-emitting element circuit 11 is removed from the state coupled to the power stage circuit 220, the sensing signal is locked, thereby locking the light-emitting element control circuit 210 to operate. Normal operating mode.

Fig. 5 shows a third embodiment of the present invention. This embodiment shows a more specific embodiment of the decision circuit 2112. As shown in FIG. 5, the judging circuit 2112 includes a comparing circuit 2112a and an optocoupler circuit 2112b. The comparison circuit 2112a is coupled to the sensing circuit 2111 (refer to FIG. 4) for receiving the sensing signal from the sensing circuit 2111, and comparing the sensing signal with the reference signal to generate a comparison result signal. The optocoupler circuit 2112b is coupled to the comparison circuit 2112a for generating a hot plug determination signal according to the comparison result signal. As shown in the figure, in the photocoupler circuit 2112b, the light emitting diodes receive, for example but not limited to, a supply voltage. When the comparison result signal is low, an optical signal is generated to conduct the crystal, and a hot plug determination circuit is generated. It should be noted that, in this embodiment, the hot plug sensing circuit 211 and the control signal generating circuit 212 (see FIG. 3A) have different working low voltages, and the hot plug sensing circuit 211 is, for example, connected to the power stage circuit 220 and the light emitting element. The circuit 11 is electrically connected and therefore has the same operating low voltage, for example, a ground potential; and the normal operating voltage of the control signal generating circuit 212 (the voltage difference interval between the operating high voltage and the low voltage) is much lower than the operating voltage of the light emitting element circuit 11, so When the operating voltage of the control signal generating circuit 212 is high, it is preferable to receive a working low voltage which is higher than the ground potential, for example, the reference potential (down arrow) shown in FIG. The optocoupler circuit 2112b is used to transmit signals between circuits operating at different operating low voltages. However, the above description is only one of the implementations. In other implementations, if the control signal generating circuit 212 and the light-emitting element circuit 11 can share the same operating low voltage, the signal can be transmitted without optical coupling. It can be directly connected, that is, the optocoupler circuit 2112b can be omitted.

Fig. 6 shows a fourth embodiment of the present invention. This embodiment shows a more specific embodiment of the hot plug sensing circuit 211 in the light emitting element control circuit 210. As shown in FIG. 6, the hot plug sensing circuit 211 includes a sensing circuit 2111 and a determining circuit 2112. The sensing circuit 2111 includes a voltage dividing circuit 2111a and a mode locking circuit 2111b. The mode lock circuit 2111b includes a conduction control circuit 2111c and an auxiliary voltage dividing circuit 2111d. The conduction control circuit 2111c is coupled to the determination circuit 2112, and is controlled by the hot plug determination signal to determine whether the auxiliary voltage divider circuit 2111d is turned on. The auxiliary voltage dividing circuit 2111d is coupled to the voltage dividing circuit 2111a. When the auxiliary voltage dividing circuit 2111d is turned on, the voltage dividing circuit 2111a and the auxiliary voltage dividing circuit 2111d integrally form a voltage dividing circuit to jointly determine the sensing signal. When the auxiliary voltage dividing circuit 2111d is not turned on, the sensing signal is separately determined by the voltage dividing circuit 2111a. Therefore, the conduction control circuit 2111c can adjust the sensing signal by determining whether the auxiliary voltage dividing circuit 2111d is turned on. When the level of the test signal changes, the hot plug determination signal generated by the judgment circuit 2112 changes (see FIG. 5).

7A-7D show third to sixth embodiments of the present invention, which show a more specific embodiment of the light-emitting element circuit 11 in combination with the above-described judging mechanism. In the four embodiments, the light emitting element circuit 11 includes, for example but not limited to, the LED circuit 10 and the resistance setting circuit 111. The LED circuit 10 includes, for example but not limited to, a plurality of light-emitting elements, such as the LED string shown in the figure, and of course, other plurality of light-emitting elements may be connected in series or in an array for coupling to the output voltage Vout to receive the output current (see Figure 3A). The resistance setting circuit 111 is coupled to the LED circuit 10 for coupling to the sensing circuit 2111 after the illuminating element circuit 11 is restored to the state coupled to the power stage circuit 220 to adjust the sensing signal and adjust the hot plug. Pull out the judgment signal. As shown in FIGS. 7A-7D, the manner in which the resistance setting circuit 111 is coupled to the LED circuit 10 may be a series connection, a parallel connection, a series connection, a parallel connection, a parallel connection, and a series connection. In detail, since the light-emitting element control circuit 210 controls the output current Iout (see FIG. 3A) in the normal operation mode, if the light-emitting element circuit 11 only includes the LED circuit 10, the output voltage Vout is not determined. By means of the resistance setting circuit 111, the light-emitting element circuit 11 can be made to have a certain resistance value, so that the output voltage Vout can be a determined known value (related to the output current Iout multiplied by the resistance value). In normal operation In the mode, the output voltage Vout is related to the output current Iout multiplied by the resistance value, and can be distinguished from the output voltage Vout when the LED circuit 10 is removed.

Figure 8 shows a ninth embodiment of the invention. This embodiment shows another embodiment of the light-emitting element control circuit 210 in the first embodiment. As shown in the figure, the light-emitting element control circuit 210 further includes a high-resistance circuit 213 coupled between the input voltage and the output voltage, in addition to the hot-swap sensing circuit 211 and the control signal generating circuit 212, for coupling between the input voltage and the output voltage. The light-emitting element circuit 11 is converted into an output voltage Vout in a state where it is not coupled to the power stage circuit 220 and the power switch is not turned on. This embodiment is intended to explain a method of converting the input voltage Vin into an output voltage Vout after the light-emitting element circuit 11 is removed from the state coupled to the power stage circuit 220 and before the light-emitting element circuit 11 is reinstalled. Mode (ie the mode of operation of the constant voltage mode). Using the high resistance circuit 213, in the normal operation mode, since its resistance value with respect to the power stage circuit 220 is high, it can be regarded as an open circuit, so the circuit is converted by the power stage circuit 220 into the output voltage Vout; After the light-emitting element circuit 11 is removed from the state coupled to the power stage circuit 220, the power stage circuit 220 can be turned off by the control signal, so that the input voltage Vin is converted to the output voltage Vout via the voltage drop of the high-resistance circuit 213. . Of course, the concept of the present invention is not limited thereto, and a high-resistance circuit may not be required. In the constant voltage mode in which the light-emitting element circuit 11 is removed, for example, the control target value of the power stage circuit 220 for the output voltage Vout may be adjusted, for example, It is not limited to adjusting the output voltage Vout to a preset voltage by adjusting an overvoltage protection mechanism (not shown), adjusting a feedback signal, adjusting a reference voltage (not shown) for comparison with a feedback signal, and the like. In this way, after the light-emitting element circuit 11 is removed from the state coupled to the power stage circuit 220, the output voltage Vout can be adjusted to a lower potential to prevent the output voltage Vout from being maintained at a high potential. .

Figure 9 shows a tenth embodiment of the present invention. This embodiment is intended to explain a specific embodiment of the voltage dividing circuit 2111a, the mode locking circuit 2111b, and the conduction control circuit 2111c and the auxiliary voltage dividing circuit 2111d in the mode locking circuit 2111b. In addition, this is The embodiments also illustrate the application of the concepts of the present invention, and it is also within the scope of the present invention to combine the elements of all of the foregoing embodiments. As shown, the voltage dividing circuit 2111a is coupled to the output voltage Vout and is divided into a sensing signal to input the comparison circuit 2112a, for example, but not limited to, a resistor connected in series. The comparison circuit 2112a compares the sensing signal with the reference signal. For example, in the normal operation mode, the reference signal is higher than the sensing signal, and the comparison result output of the comparison circuit is maintained at a high level, and the hot plug determination signal is maintained at a high level, for example. The representative light-emitting element circuit 11 is still coupled to the power stage circuit 220. In the normal operation mode, the conduction control circuit 2111c in the mode lock circuit 2111b is turned on to constitute a bypass short circuit so that the auxiliary voltage dividing circuit 2111d is equal to non-conduction, so that the sensing signal remains lower than the reference signal.

On the other hand, when the light-emitting element circuit 11 is removed, that is, the state coupled to the power stage circuit 220 becomes uncoupled, the output voltage Vout suddenly rises abruptly, the sensing signal is higher than the reference signal, and the comparison circuit outputs The comparison result signal is lowered from a high potential to a low potential, and the hot plug determination signal is also changed from a high potential to a low potential, for example. At this time, the conduction control circuit 2111c in the mode locking circuit 2111b is not turned on, so the auxiliary voltage dividing circuit 2111d is turned on to function, and the voltage dividing circuit 2111a determines the sensing signal together, and the sensing signal is higher than the reference signal. According to the hot plug determination signal, the control signal generated by the control signal generating circuit 212 causes the power stage circuit 220 to be non-conducting. Therefore, the input voltage Vin is converted to the output voltage Vout via the voltage drop of the high resistance circuit 213, and the output voltage Vout is instantaneous. The elevated state drops and remains at a lower preset level, entering the constant voltage control mode. Although the output voltage is lowered in the constant voltage control mode, since the conduction control circuit 2111c is not turned on, the auxiliary voltage dividing circuit 2111d and the voltage dividing circuit 2111a jointly determine the sensing signal, so the sensing signal can still be locked higher than Reference signal. After the light-emitting element circuit 11 is replaced, the output voltage Vout is changed by the resistance setting circuit in the light-emitting element circuit 11, and the sensing signal is correspondingly lowered below the reference signal, so that the operation mode returns to the normal operation mode.

Fig. 10 is a view showing waveforms of respective signals in the foregoing embodiments. As shown As shown, after the circuit is started, the input voltage Vin and the output voltage Vout rise, and the LED power control circuit adjusts Iout to a fixed preset current. When the LED circuit is removed in the normal operation mode, the output current Iout drops to zero current, and the output voltage Vout rises instantaneously, and the output voltage Vout related signal or the output current Iout related signal can be sensed, and the hot plug sensing is adjusted. The signal enters the constant voltage control mode to adjust the output voltage Vout to a lower preset level when the target is removed.

When the LED circuit is replaced, the output voltage Vout is instantaneously reduced. At this time, the hot plug sensing signal can be adjusted to return to the normal operation mode, and the output current Iout is adjusted to a fixed preset current when the target is replaced.

The present invention has been described with reference to the preferred embodiments thereof, and the present invention is not intended to limit the scope of the present invention. In the same spirit of the invention, various equivalent changes can be conceived by those skilled in the art. For example, in the embodiments, the two circuits or components directly connected may be inserted with other circuits or components that do not affect the main function; for example, the light-emitting elements are not limited to the LEDs shown in the respective embodiments. It can also be extended to all components driven by current; for example, the meaning of the digital signal level can be interchanged, only need to modify the circuit to deal with the signal; for example, the input of the amplifier circuit and the comparison circuit are positive and negative Can be interchanged, only need to correspond to the signal processing method of the correction circuit. All such modifications may be made in accordance with the teachings of the present invention, and the scope of the present invention should be construed to cover the above and other equivalents.

11‧‧‧Lighting element circuit

200‧‧‧Lighting element power control circuit

210‧‧‧Lighting element control circuit

211‧‧‧Hot-plug sensing circuit

212‧‧‧Control signal generation circuit

220‧‧‧Power level circuit

Vin‧‧‧Input voltage

Vout‧‧‧ output voltage

Claims (11)

A light-emitting element control circuit for generating a control signal to operate a power stage circuit in a normal operation mode, and converting an input voltage to an output voltage for supplying an output current to a light-emitting element circuit The illuminating element control circuit includes: a hot plug sensing circuit, configured to generate a hot plug determination signal according to the output voltage, so that after the illuminating element circuit is removed from being coupled to the power stage circuit, And after the re-installation of the light-emitting element circuit, the hot-plug determination signal is adjusted to determine that the light-emitting element control circuit operates in a certain voltage control mode or the normal operation mode; and a control signal generation circuit, respectively The control circuit is coupled to the power stage circuit and the hot plug sensing circuit to adjust the control signal according to the hot plug determination signal, so that when the light emitting element circuit is removed in the normal operation mode, the operation is performed. a voltage control mode, and adjusting the output voltage to a predetermined level, and when the light-emitting element circuit is coupled to the power stage circuit After the condition, the operation in the normal operation mode. The illuminating device control circuit of claim 1, wherein the hot plug sensing circuit comprises: a sensing circuit for generating a sensing signal according to the output voltage; and a determining circuit, The sensing circuit is coupled to generate the hot plug determination signal according to the sensing signal. The illuminating device control circuit of claim 2, wherein the sensing circuit comprises: a voltage dividing circuit for generating the sensing signal according to the output voltage; and a mode locking circuit respectively The voltage dividing circuit and the determining circuit are coupled to be used after the light emitting element circuit is removed from being coupled to the power stage circuit, and Before the light-emitting element circuit is reinstalled, the sensing signal is locked, thereby locking the light-emitting element control circuit to operate in the constant voltage control mode; and after the light-emitting element circuit is removed and reinstalled, the light-emitting element circuit is The sensing signal is locked before being removed from the condition coupled to the power stage circuit, thereby locking the light emitting element control circuit to operate in the normal operating mode. The light-emitting element control circuit of claim 3, wherein the light-emitting element circuit comprises: at least one light-emitting element coupled to the power stage circuit, and receiving the output current in the normal operation mode; And a resistance setting circuit coupled to the illuminating element for coupling to the sensing circuit after the illuminating element circuit is restored to the state coupled to the power stage circuit to adjust the sensing signal, and further Adjust the hot plug determination signal. The illuminating device control circuit of claim 3, wherein the mode locking circuit comprises: an auxiliary voltage dividing circuit coupled to the voltage dividing circuit; and a conduction control circuit, and the determining circuit and the The auxiliary voltage dividing circuit is coupled, and the conduction control circuit is controlled by the hot plug determination signal to determine whether the auxiliary voltage dividing circuit is turned on, wherein the voltage dividing circuit and the auxiliary voltage dividing circuit are turned on The auxiliary voltage dividing circuit jointly determines the sensing signal, and when the auxiliary voltage dividing circuit is not turned on, the sensing signal is separately determined by the voltage dividing circuit. The illuminating element control circuit of claim 2, wherein the hot plug sensing circuit and the control signal generating circuit have different operating low voltages, and the determining circuit comprises: a comparison circuit coupled to the sensing circuit for generating a comparison result signal according to the sensing signal and a reference signal; and an optocoupler circuit coupled to the comparison circuit for determining the comparison result according to the comparison The signal generates the hot plug determination signal. The illuminating element control circuit of claim 1, further comprising a high resistance circuit coupled between the input voltage and the output voltage, wherein the illuminating element circuit is uncoupled from the power stage circuit When the power switch is not turned on, the input voltage is step-down converted to the output voltage. A hot plug sensing circuit for a light emitting element control circuit, wherein the light emitting element control circuit generates a control signal to operate a power stage circuit in a normal operation mode, and converts an input voltage into an output voltage to Supplying an output current to a light-emitting element circuit, wherein the hot-plug sensing circuit is configured to generate a hot-plug determination signal according to the output voltage, so that the light-emitting element circuit is coupled to the power stage circuit After being removed, and after reinstalling the light-emitting element circuit, the hot-plug determination signal is adjusted to determine that the light-emitting element control circuit operates in a certain voltage control mode or the normal operation mode, the hot plug The sensing circuit includes: a sensing circuit for generating a sensing signal according to the output voltage; and a determining circuit coupled to the sensing circuit for generating the hot plug according to the sensing signal a sensing circuit, wherein the sensing circuit comprises: a voltage dividing circuit for generating the sensing signal according to the output voltage; and a mode locking circuit, And the voltage dividing circuit and the determining circuit are coupled to be used after the light emitting element circuit is removed from being coupled to the power stage circuit, and before the light emitting element circuit is reinstalled, Sense signal, and further Locking the light-emitting element control circuit to operate in the constant voltage control mode; and after reinstalling the light-emitting element circuit after removal, before the light-emitting element circuit is removed from the state coupled to the power stage circuit, The sensing signal is locked, thereby locking the lighting element control circuit to operate in the normal operating mode. The hot plug sensing circuit for use in a light emitting device control circuit according to claim 8, wherein the mode locking circuit comprises: an auxiliary voltage dividing circuit coupled to the voltage dividing circuit; and a conductive a control circuit coupled to the determination circuit and the auxiliary voltage dividing circuit, wherein the conduction control circuit is controlled by the hot plug determination signal to determine whether the auxiliary voltage dividing circuit is turned on, wherein the auxiliary voltage dividing circuit is turned on The voltage dividing circuit and the auxiliary voltage dividing circuit jointly determine the sensing signal, and when the auxiliary voltage dividing circuit is not turned on, the sensing signal is separately determined by the voltage dividing circuit. The hot plug sensing circuit for the light emitting device control circuit of claim 8, wherein the hot plug sensing circuit and the control signal generating circuit have different operating low voltages, and the determining circuit comprises: a comparison The circuit is coupled to the sensing circuit for generating a comparison result signal according to the sensing signal and a reference signal; and an optocoupler circuit coupled to the comparison circuit for detecting the comparison result signal, The hot plug determination signal is generated. A light-emitting element circuit is hot-swappable and coupled to an output voltage, and the light-emitting element circuit is controlled by a light-emitting element control circuit, and the light-emitting element control circuit determines the operation according to whether the light-emitting element circuit is coupled to the output voltage In a certain voltage control mode or a normal operation mode, the light emitting element circuit includes: a plurality of light emitting elements for coupling with the output voltage; a resistance setting circuit coupled to the plurality of light emitting elements for determining the output voltage according to a current flowing through the light emitting element circuit when the light emitting element circuit is coupled to the output voltage, wherein the light emitting element circuit When the output voltage is coupled to the output voltage, the output voltage is different.