Operating device for a lighting device

Abstract

The invention relates to an operating device (400) for a lighting arrangement, the operating device comprising: an output terminal (407a, 407b) for supplying a lighting arrangement (408) such as for example an LED load; a control circuit (404) for controlling a power supply of the lighting arrangement (408); an NFC module (406) configured to receive an NFC signal and to output a pulse width modulated, PWM, signal with a variable duty cycle; and a conversion circuit (405) arranged for being supplied with the PWM signal and for outputting a DC voltage supplied to an input of the control circuit (404). The DC voltage is a function of the duty cycle of the PWM signal according to a set conversion rate, wherein the conversion circuit (405) is configured to be supplied with an internal control signal or an external control signal to set at least two conversion rates.

Description

Technical Field

[0001] This invention generally belongs to the field of operating devices for lighting apparatuses that can be controlled via NFC communication. Background Technology

[0002] Near Field Communication (NFC) modules can be used to configure LED drivers or other operating devices for lighting fixtures. Typically, the control circuitry of the LED driver or operating device (such as a microcontroller) can be used to communicate with the NFC module.

[0003] It is known that such NFC modules can be used to convert the configuration signal of an LED driver into a pulse-width modulated signal (e.g., representing the LED current), which can be fed to the integrated control circuitry of the LED driver without further intelligence, such as additional control circuitry or microcontrollers.

[0004] Typically, such NFC modules convert NFC signals into PWM signals via integrated circuits on the NFC module, where the duty cycle of the PWM signal reflects the wirelessly received signal.

[0005] Furthermore, it is known that the control circuitry for the operating equipment of a lighting device may include a programming input pin at which such an analog DC voltage can be supplied to allow the nominal value of the input current to be applied through the lighting device, particularly through the LED load.

[0006] Therefore, the nominal current of an LED can be programmed using NFC communication.

[0007] Furthermore, in some cases, LED current selection may be required. However, the previously mentioned solutions utilize NFC modules, which require the presence of control circuitry such as a microcontroller. This increases the complexity of the NFC module.

[0008] Furthermore, many operating devices possess so-called "DC level characteristics," which allow for the detection and differentiation between AC and DC supply voltages. However, without additional intelligence, it is difficult to implement such DC level characteristics in operating devices.

[0009] Therefore, the aim is to provide improved operating equipment for lighting devices. Summary of the Invention

[0010] The object of this invention is achieved by the solution provided in the appended independent claims. Advantageous embodiments of the invention are further defined in the dependent claims.

[0011] According to a first aspect, the present invention relates to an operating device for a lighting apparatus, the operating device comprising: an output terminal supplying the lighting apparatus, such as an LED load; a control circuit for controlling the power supply of the lighting apparatus; an NFC module configured to receive an NFC signal and output a pulse width modulation (PWM) signal having a variable duty cycle; and a conversion circuit arranged to supply the PWM signal and to output a DC voltage supplied to an input terminal of the control circuit. Furthermore, the DC voltage is a function of the duty cycle of the PWM signal according to a set slew rate, and the conversion circuit is configured to supply an internal control signal or an external control signal to set at least two slew rates.

[0012] This offers the advantage that, by using the NFC module mentioned above, no further intelligence is required within the operating device for the lighting fixture, which can be configured via the NFC module. The control circuitry can be a microcontroller. The control signals can include AC or DC voltage signals.

[0013] In an implementation of the first aspect, the control circuit is configured to map the level of the supplied DC voltage to the nominal current of the LED load and, for example, to control the operation of the lighting device by controlling the switching operation of at least one switch of a switching converter to match the actual current with the nominal current.

[0014] In the implementation of the first aspect, the conversion rate can be changed continuously or incrementally by the control signal.

[0015] In an implementation of the first aspect, the conversion circuit includes an RC low-pass filter configured to convert the PWM signal into a DC voltage.

[0016] In an implementation of the first aspect, the operating device includes a detection circuit configured to detect whether the supply voltage of the operating device is AC or DC, and a control signal that sets the conversion rate differently depending on whether an AC or DC signal is present.

[0017] This provides the advantage of the operating device having DC level characteristics, enabling it to detect whether the mains voltage is AC or DC. Upon detecting a DC signal, such as from a battery within the operating device, the output current of the operating device for lighting fixtures (e.g., an LED driver) can be reduced, allowing the battery to operate for a longer period, for example, in an emergency.

[0018] In the implementation of the first aspect, the detection circuit includes a voltage divider, an RC low-pass filter, or a capacitor.

[0019] In an implementation of the first aspect, the operating device includes a limiting circuit configured to limit a DC voltage when the detected control signal is a DC signal.

[0020] In the implementation of the first aspect, the limiting circuit includes a Zener diode configured to clamp a DC signal.

[0021] In the implementation of the first aspect, the limiting circuit includes a switch configured to switch if the control signal is a DC signal.

[0022] Specifically, the switch is configured to connect the detection circuit and the limiting circuit.

[0023] In the first implementation, the NFC module is configured to program the nominal current of the LED load.

[0024] According to a second aspect, the present invention relates to a system comprising an NFC transmitting handheld device and an operating device according to the first aspect or any implementation thereof.

[0025] According to a third aspect, the present invention relates to a method for operating a device for a lighting apparatus, the method comprising: supplying a lighting apparatus, such as an LED load, via an output terminal; controlling the power supply of the lighting apparatus; receiving an NFC signal; outputting a pulse width modulation (PWM) signal having a variable duty cycle; supplying the PWM signal to a conversion circuit; and outputting a DC voltage supplied to an input terminal of a control circuit, wherein the DC voltage is a function of the duty cycle of the PWM signal according to a set conversion rate, wherein the conversion circuit is configured to be supplied with an internal control signal or an external control signal to set at least two conversion rates. Attached Figure Description

[0026] The present invention will now be described in conjunction with the accompanying drawings.

[0027] Figure 1 A schematic representation of an operating device for a lighting apparatus according to one embodiment is shown;

[0028] Figure 2 A schematic representation of the NFC and NFC output signal processing section of an operating device for a lighting apparatus according to one embodiment is shown;

[0029] Figure 3 A schematic representation of the NFC and NFC output signal processing section of an operating device for a lighting apparatus according to one embodiment is shown;

[0030] Figure 4 A schematic representation of the NFC and NFC output signal processing section of an operating device for a lighting apparatus according to one embodiment is shown;

[0031] Figure 5 A schematic representation of the NFC and NFC output signal processing section of an operating device for a lighting apparatus according to one embodiment is shown;

[0032] Figure 6 A schematic representation of PWM signals and voltage signals in an operating device for a lighting fixture according to one embodiment is shown;

[0033] Figure 7 A schematic representation of PWM signals and voltage signals in an operating device for a lighting fixture according to one embodiment is shown;

[0034] Figure 8 A schematic representation of an AC / DC detection circuit for an operating device for a lighting fixture, according to one embodiment, is shown.

[0035] Figure 9 A schematic representation of an AC / DC detection circuit for an operating device for a lighting fixture, according to one embodiment, is shown.

[0036] Figure 10 A schematic representation of an AC / DC detection circuit for an operating device for a lighting fixture, according to one embodiment, is shown.

[0037] Figure 11 A schematic representation of an AC / DC detection circuit for an operating device for a lighting fixture, according to one embodiment, is shown.

[0038] Figure 12 A schematic representation of the AC / DC detection section of an operating device for a lighting fixture according to one embodiment is shown; and

[0039] Figure 13 A schematic representation of a method for operating a device for a lighting apparatus according to one embodiment is shown. Detailed Implementation

[0040] This document describes aspects of the invention in the context of operating equipment for lighting devices.

[0041] The invention is described more fully below with reference to the accompanying drawings, in which various aspects of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the aspects of the invention presented in this disclosure. Rather, these aspects are provided so that this disclosure will be comprehensive and complete, and will fully convey the scope of the invention to those skilled in the art. The aspects of the invention shown in the drawings may not be drawn to scale. Rather, the dimensions of various features may be enlarged or reduced for clarity. Furthermore, some drawings may be simplified for clarity. Therefore, the drawings may not show all components of a given device.

[0042] Various aspects of the operating apparatus for a lighting device will be presented. However, as will be readily understood by those skilled in the art, these aspects can be extended to various aspects of the operating apparatus for a lighting device without departing from the present invention.

[0043] The term "LED luminaire" should refer to a luminaire having a light source including one or more LEDs or OLEDs. LEDs are well known in the art, and therefore will only be briefly discussed to provide a complete description of the invention.

[0044] It should also be understood that aspects of the invention may include integrated circuits that are easily manufactured using conventional semiconductor technologies, such as complementary metal-oxide-semiconductor technology, or simply "CMOS". Furthermore, aspects of the invention may be implemented using other manufacturing processes used for manufacturing optical and electrical devices. Specific embodiments of exemplary aspects, as illustrated in the accompanying drawings, will now be described in detail. The same reference numerals will be used throughout the drawings and in the following detailed description to refer to the same or similar parts.

[0045] Figure 1 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0046] The operating device 400 for the lighting device 408 can be fed AC or DC voltage at input terminals 401a and 401b. Furthermore, the operating device 400 for the lighting device 408 includes: output terminals 407a and 407b for supplying the lighting device 408 with a load such as an LED; a control circuit 404 for controlling the power supply of the lighting device 408; an NFC module 406 configured to receive NFC signals and output a pulse width modulation (PWM) signal with a variable duty cycle; and a conversion circuit 405 arranged to supply the PWM signal and to output the DC voltage supplied to the input terminal of the control circuit 404. The DC voltage is a function of the duty cycle of the PWM signal according to a set slew rate, and the conversion circuit 405 is configured to supply an internal control signal or an external control signal to set at least two slew rates.

[0047] Internal or external control signals may include AC voltage signals or DC voltage signals.

[0048] In addition, the operating device 400 may include a detection circuit 402 configured to detect whether the power supply voltage of the operating device is AC or DC and to set the conversion rate in different ways depending on whether an AC signal or a DC signal is present.

[0049] In addition, the operating device 400 may include a limiting circuit 403 configured to limit the DC voltage when the detected control signal is a DC signal.

[0050] The NFC module 406 can be configured to convert the current configuration into a pulse width modulation (PWM) signal, which can then be filtered and used as current selection information for the LED control integrated circuit or control circuit 404.

[0051] Advantageously, with DC voltage at input terminals 401a and 401b, the output current of the LED driver or operating device 400 can be reduced, allowing the battery inside the LED driver or operating device 400 to operate for a longer period of time, for example, in an emergency.

[0052] Figure 2 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0053] Figure 2 An NFC module 406 (antenna and processing circuitry) is shown connected to a voltage divider 500, which in turn connects to a low-pass RC filter 501. In this embodiment, the RC filter 501 forms a conversion circuit 405. Specifically, it can be shown that the dimming voltage Vdim at the output of the RC filter 501 can depend on the duty cycle of the PWM signal. Furthermore, it can be shown that the pulse width modulation (PWM) of the input signal to the NFC module 406 is linearly related to a set LED current. The frequency of the PWM signal can be in the range of 1 kHz to 30 kHz, while the PWM voltage level can be in the range of 0 V to 2.8 V. Additionally, an analog signal can be obtained via the RC low-pass filter 501.

[0054] In addition, Figure 2 In this circuit, an AC / DC signal is provided as input to the limiting circuit 403, and a voltage divider 500, including two resistors, is connected to the NFC module 406 and the RC filter 501. The module 502 of the operating device 400 may include a control circuit 404. Figure 2 (Not shown in the image).

[0055] Generally, the operating device 400 can be adapted to operate in different configurations: the high level of the PWM signal at the output of the NFC module 406 can be adapted according to the power supply signal (configuration options 1a and 1b), or the filtered analog signal at the output of the RC low-pass filter 501 can be adapted according to the power supply signal (configuration options 2a and 2b). Here, the power supply signal can refer to the power supply voltage of the operating device 400.

[0056] For example, according to configuration option 1a, the high level of the PWM signal at the output of the NFC module 406 is adapted via a voltage divider 500, which divides the voltage in the case of a DC power supply signal. In the case of an AC power supply signal, no voltage division is performed.

[0057] Figure 3 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0058] Figure 3 It shows something similar to Figure 2 The circuit shown is a circuit where, instead of voltage divider 500, a Zener diode 600 is added to the circuit, and an AC / DC voltage is supplied as input to the Zener diode 600.

[0059] In configuration option 1b, the high level of the PWM signal at the output of the NFC module 406 is adapted via a Zener diode 600. Under DC voltage, the voltage is clamped by the Zener diode 600, while under AC voltage, the voltage is not clamped.

[0060] Figure 4 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0061] Figure 4 It shows something similar to Figure 2 The circuit incorporates a voltage divider 500 at the output of the RC low-pass filter 501, instead of at the output of the NFC module 406. In this manner, the analog signal at the output of the RC filter is adapted by the voltage divider 500, according to configuration option 2a. With a DC input voltage, the voltage is divided, while with an AC input voltage, the voltage is not divided.

[0062] Figure 5 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0063] Specifically, Figure 5 It shows something similar to Figure 2The circuit is configured such that a Zener diode 600 is added to the output of the RC low-pass filter 501. In this case, according to configuration option 2b, the filtered analog signal at the output of the RC low-pass filter is adapted via the Zener diode 600. With a DC input voltage, the voltage is clamped, while with an AC input voltage, the voltage is not clamped.

[0064] Figure 6 A schematic representation of PWM signals and voltage signals in an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0065] Figure 6 The effect of the DC level characteristics of the operating device 400 on the AC power supply signal is shown.

[0066] Specifically, in the case of configuration options 1a, 1b, 2a and 2b, the PWM NFC signal at the output of NFC module 406 is shown on the upper panel (case “PWM NFC chip output”).

[0067] In addition, for configuration options 1a, 1b, 2a and 2b, the PWM signal at the input of the RC filter is shown on the middle panel (case “PWM RC filter input”).

[0068] Finally, for configuration options 1a, 1b, 2a, and 2b, the dimming voltage Vdim or DC voltage (i.e., the voltage at the output of the RC low-pass filter 501) is shown as a function of the duty cycle of the PWM signal on the lower panel (case “Vdim and Duty Cycle”).

[0069] from Figure 6 As can be seen, in the case of an AC signal, the voltage Vdim or DC voltage will not change in any configuration option.

[0070] In some operating devices 400 used for lighting fixtures 408, the DC level or slew rate can be set in the range of 0% to 100% dimming level, while in other devices it can be fixed at, for example, 70% of the dimming level.

[0071] Figure 7 A schematic representation of PWM signals and voltage signals in an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0072] Figure 7 The effect of the DC level characteristics of the operating device 400 on a DC power supply signal is shown.

[0073] Specifically, for all configuration options 1a, 1b, 2a and 2b, the PWM NFC signal at the output of the NFC module 406 is shown on the upper panel (case “PWM NFC chip output”).

[0074] Furthermore, for all configuration options 1a, 1b, 2a, and 2b, the PWM signal at the input of the RC filter 501 is shown on the middle panel (case “PWM RC Filter Input”). From Figure 7 As can be seen, in this case, for configuration options 1a and 1b, the DC voltage level is reduced at the input of the PWM RC filter 501.

[0075] Finally, for configuration options 1a, 1b, 2a, and 2b, the dimming voltage Vdim or DC voltage (i.e., the voltage at the output of the RC low-pass filter 501) is shown as a function of the duty cycle of the PWM signal on the lower panel (case “Vdim vs. Duty Cycle”). In all cases, the dimming voltage or DC voltage as a function of the duty cycle of the PWM signal reaches its maximum value, i.e., the DC voltage level.

[0076] Specifically, if, for example, a DC trunk voltage is applied, the voltage Vdim is affected by the switching connection voltage divider 500 or the Zener diode 600. Thus, a circuit can be implemented to switch in the case of a DC trunk, as will be described with reference to the following figures.

[0077] Figure 8 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0078] exist Figure 8 In the illustrated embodiment, the operating device 400 for the lighting device 408 includes a detection circuit 402, a limiting circuit 403, and a rectifier bridge 1105.

[0079] Specifically, the detection circuit 402 includes two rectifier diodes 1101, a voltage divider 1100, an RC filter 1102, and a capacitor 1103. The input voltage comes from the L line and N line, where the input voltage is rectified by the rectifier bridge 1105. Furthermore, the limiting circuit 403 includes a switch 1104.

[0080] With AC voltage, for example at a frequency f = 100 Hz, the time constant of the RC filter is much longer than 10 ms and the switch 1104 (e.g., FET) will not switch. This can also be seen in the graph of the threshold th 1106, which is higher than the voltage value that allows the switch 1104 to switch.

[0081] Figure 9A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0082] Figure 9 It shows something similar to Figure 8 The circuit shown differs in that, in this case, the input voltage is a DC voltage, i.e., the frequency f = 0 Hz. In this case, capacitor 1103 charges according to the time constant of the RC low-pass filter, and switch 1104 (FET) switches. This can also be seen in the graph of threshold th 1106, which is below the voltage value that allows switch 1104 to switch.

[0083] Figure 10 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0084] Figure 10 It shows something similar to Figure 8 and Figure 9 The circuit is similar to the one described above, except that the detection circuit 402 does not include the rectifier diode 1101. Furthermore, in this embodiment, only the L line is sensed. This provides an advantage, as sensing only the L line is cheaper.

[0085] With AC supply voltage, for example at a frequency f = 50Hz, the time constant of the RC low-pass filter 1102 is much longer than 20ms and the switch 1104 FET will not switch. This can also be seen in the graph of the threshold th 1106, which is higher than the voltage value that allows switch 1104 to switch.

[0086] Figure 11 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0087] Figure 11 It shows something similar to Figure 10 The circuit shown is a DC voltage signal, i.e., frequency f = 0Hz. Capacitor 1103 charges according to the time constant of the RC low-pass filter 1102, and switch 1104 (FET) switches. This can also be seen in the graph of threshold th 1106, which is below the voltage value that allows switch 1104 to switch.

[0088] Figure 12 A schematic representation of an operating device 400 for a lighting device 408 according to one embodiment is shown.

[0089] Specifically, Figure 12 The selection of some elements that may be included in the operating device 400 for the lighting device 408 according to one embodiment is shown.

[0090] Specifically, Figure 12 The operating device 400 includes a detection circuit 402, a limiting circuit 403, a conversion circuit 405, an NFC module 406, and a rectifier bridge 1105. Signals from the L line and N line are given as inputs to the detection circuit 402.

[0091] The detection circuit 402 may include two rectifier diodes 1101, a voltage divider 1100, an RC low-pass filter 1102, and a capacitor 1103.

[0092] In addition, the limiting circuit 403 may include a switch 1104 and a Zener diode 600. The switch 600 is configured to switch if the input signal or control signal is a DC signal.

[0093] NFC module 406 includes an NFC antenna that transmits signals to unit 406a, which then converts the received signals into a PWM signal. The PWM signal is given as an input signal to conversion circuit 405. In this embodiment, conversion circuit 405 includes an RC low-pass filter 501. The output signal of RC filter 501 is given as an input to control circuit 404 (…). Figure 12 Module 502 (not shown in the image).

[0094] Specifically, Figure 12 An example of a limiting circuit 403 for 70% of DC level or slew rate is shown.

[0095] In this implementation, configuration option 2b is used to influence the Vdim signal or DC voltage at the output of the RC low-pass filter 501 via Zener 600, and configuration options 1a and 1b are used to detect the DC voltage and switch via sensing L and N.

[0096] Therefore, by utilizing the detection circuit 402 to detect the DC trunk voltage, the high level of the PWM signal output of the NFC module 406 is affected in such a way that the resulting analog signal at the output of the RC low-pass filter 501 is related to the DC dimming level relative to the selected LED current or the current of the operating device 400 via the NFC module 406.

[0097] Figure 13 A schematic representation of a method 1600 for operating a device 400 for a lighting device 408 is shown according to one embodiment.

[0098] Method 1600 includes the following steps:

[0099] -Supply the 1601 lighting device 408, such as an LED load, via output terminals 407a and 407b;

[0100] - Control the power supply of lighting device 408 1602;

[0101] - Receives 1603 NFC signals;

[0102] - Outputs a 1604-pulse-width modulation (PWM) signal with a variable duty cycle;

[0103] - Supply a 1605 PWM signal to the conversion circuit 405;

[0104] - Output 1606 supplies DC voltage to the input terminal of control circuit 404, wherein the DC voltage is a function of the duty cycle of the PWM signal according to the set conversion rate, wherein conversion circuit 405 is configured to be supplied with internal control signal or external control signal to set at least two conversion rates.

[0105] All features of all embodiments described, shown, and / or protected by the claims herein may be combined with each other.

[0106] While various embodiments of the invention have been described above, it should be understood that these embodiments are given by way of example only and not by way of limitation. Various modifications may be made to the embodiments disclosed herein without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention should not be limited by any of the above embodiments. Rather, the scope of the invention should be defined by the following claims and their equivalents.

[0107] While the invention has been shown and described with respect to one or more specific embodiments, equivalent alternatives and modifications will arise to those skilled in the art upon reading this specification and the accompanying drawings. Furthermore, although specific features of the invention may be disclosed only with respect to a few specific embodiments, such features may be combined with one or more other features of other embodiments to meet the expectations and advantages of any given or particular application.

Claims

1. An operating device (400) for a lighting device, the operating device comprising: - Output terminals (407a, 407b) supplying power to a lighting device (408), the lighting device (408) including an LED load. - Control circuit (404), the control circuit being used to control the power supply of the lighting device (408); - NFC module (406), the NFC module being configured to receive NFC signals and output pulse width modulation (PWM) signals with variable duty cycles; - A conversion circuit (405) is arranged to supply the PWM signal and to output a DC voltage supplied to the input of the control circuit (404). Wherein, the DC voltage is a function of the duty cycle of the PWM signal according to the set conversion rate. The conversion circuit (405) is configured to be supplied with an internal control signal or an external control signal to set at least two conversion rates. The operating device (400) includes a detection circuit (402) configured to detect whether the power supply voltage of the operating device is AC or DC and to set the conversion rate in different ways depending on whether an AC or DC signal is present.

2. The operating device (400) according to claim 1, wherein, The control circuit (404) is configured to map the level of the supplied DC voltage to the nominal current of the LED load and to control the operation of the lighting device (408).

3. The operating device (400) according to claim 1 or 2, wherein, The conversion rate can be changed continuously or gradually by means of the control signal.

4. The operating device (400) according to claim 1, wherein, The conversion circuit (405) includes an RC low-pass filter (501) configured to convert the PWM signal into the DC voltage.

5. The operating device (400) according to claim 1, wherein, The detection circuit (402) includes a voltage divider (1100) or an RC low-pass filter (1102) or a capacitor (1103).

6. The operating device (400) according to claim 1, wherein, The operating device (400) includes a limiting circuit (403) configured to limit the DC voltage when the detected control signal is a DC signal.

7. The operating device (400) according to claim 6, wherein, The limiting circuit (403) includes a Zener diode (600) configured to clamp the DC signal.

8. The operating device (400) according to claim 6, wherein, The limiting circuit (403) includes a switch (1104) configured to switch if the control signal is a DC signal.

9. The operating device (400) according to claim 1, wherein, The NFC module (406) is configured to program the nominal current of the LED load.

10. The operating device (400) according to claim 2, wherein, The operation of the lighting device (408) is controlled by controlling the switching operation of at least one switch of the switching converter so that the actual current matches the nominal current.

11. A system comprising an NFC transmitting handheld device and an operating device (400) according to any one of claims 1 to 10.

12. A method (1600) for operating an operating device (400) for a lighting device (408), the method comprising - The lighting device (408) is supplied (1601) via the output terminals (407a, 407b); - Control the power supply of the lighting device (408) (1602); - Receive (1603) NFC signal; - Output (1604) a pulse width modulation (PWM) signal with a variable duty cycle; - Supply the PWM signal (1605) to the conversion circuit (405); - The output (1606) supplies the DC voltage to the input terminal of the control circuit (404), wherein, The DC voltage is a function of the duty cycle of the PWM signal according to a set slew rate, wherein the conversion circuit (405) is configured to be supplied with an internal control signal or an external control signal to set at least two slew rates. The operating device (400) includes a detection circuit (402) configured to detect whether the power supply voltage of the operating device is AC or DC and to set the conversion rate in different ways depending on whether an AC or DC signal is present.

Images