RETROFIT TUBULAR LAMP WITH SINGLE SWITCH DEVICE - Patent application

Abstract

The retrofit tubular lamp has a single switch device configured to selectively connect a first end and a second end of an input interface to one another. When the two ends are connected, a converter is bypassed while providing power to a light emitting device of the lamp. When the two ends are disconnected, power is provided to the light emitting device via the converter. The single switch device is further configured such that when the two ends are disconnected from one another, a creepage distance between the two ends is equal to or greater than a predetermined safety distance (i.e., a safety creepage is created).

Description

[Technical field]

[0001] The present invention relates to the field of retrofit tubular lamps, and in particular to retrofit tubular lamps that can be powered using two different types of power sources. [Background technology]

[0002] There is growing interest in retrofit tubular lamps to replace or retrofit older lighting units, such as certain fluorescent tube lamps. These retrofit tubular lamps need to be designed so that they can draw power from a power source, such as a ballast, that was originally designed to power fluorescent lamps. However, as the market grows, there is also growing business interest in new installations that do not have ballasts, meaning that the retrofit tubular lamps can draw power directly from a utility power source, such as AC mains, and / or rewired installations where the ballast (e.g., part of the ballast) has been modified, bypassed, and / or removed.

[0003] It would therefore be beneficial if a retrofit tubular lamp could be configured to draw power from two types of power sources: the first type may be a high frequency power source designed to power fluorescent lamps (i.e., including a ballast), such as an electronic ballast, and the second type may be a low frequency power source including at least an AC mains power source, and may include an electromagnetic (EM) ballast. Summary of the Invention [Problem to be solved by the invention]

[0004] There is a continuing desire to reduce the size, cost, and material requirements of the circuits used for retrofit tubular lamps. For example, there is also a desire to increase safety for installers of retrofit tubular lamps to reduce the possibility that an installer may provide an electrical current path during installation of the retrofit tubular lamp. [Means for solving the problem]

[0005] The invention is defined by the claims.

[0006] A necessary feature of a retrofit tubular lamp is, as explained above, to configure the lamp to operate from both types of power sources while ensuring sufficient safety for the lamp installer or fitter (i.e. when connecting the lamp to a power source). One problem is that there needs to be sufficient safety creepage between the two ends of the input interface of the lamp to prevent the occurrence of undesired current flow between the two ends.

[0007] Figure 1 shows an existing retrofit tubular lamp 100 that meets these requirements. The lamp 100 has a pin safety circuit 105, such as a relay with a safety creepage between the two ends 111, 112 of the input interface of the lamp. The pin safety circuit is substantially open (via an open relay, optionally allowing a maximum body-safe current to flow through a Y-capacitor) when a human body is touching one end 111 of the input interface of the lamp 100 while the other end 112 of the lamp is connected to a first type of power supply (and vice versa), and the pin safety circuit 105 is closed (via a closed relay) when both ends of the lamp are connected to the first type of power supply without a human body between them.

[0008] Another requirement of a retrofit tubular lamp (adapted for both types of power supplies) is to have a converter 150, for example to convert the mains voltage to a suitable level for the light emitting devices LEDs1 of the lamp 100. However, if a high frequency power supply supplies the retrofit tubular lamp, this converter 150 needs to be bypassed or turned off, since the high frequency power supply can already regulate the LED current and there is no need to use the converter 150 anymore. In some known examples, a MOSFET (or similar transistor-based switch) is used to bypass the converter. In FIG. 1, the MOSFET is shown as a bypass MOS M1, and the converter 150 is a switch-mode power converter, more specifically a buck converter. The buck converter 150 is formed from a controllable MOSFET switch M2, a diode D39, an inductor L1 and an output storage capacitor C7. Such an arrangement of the buck converter is conventional in the art and will not be described for the sake of brevity. It is noted that other topologies of converters are also applicable.

[0009] Other components of the existing retrofit tubular lamp 100 include rectifier circuits D33, D35, D34, D36, D37, and D38, a matching circuit 140, and a capacitor C8, whose operation follows the conventional procedure of a retrofit tubular lamp.

[0010] The present disclosure proposes an approach to consolidate the above requirements by integrating or combining the bypass switch for the converter and the pin safety circuit providing the safety creepage into a single switch device connected between the first and second ends of the input interface. This ensures that there is a safety creepage between the first and second ends when the mains or EM ballast powers the converter, improving the safety of the installation or mounting of the lamp. In particular, the risk of mains or EM ballast current being conducted through the installer or installer, for example when the first end is connected to the retrofit tubular lamp before installation is completed, is significantly reduced. Furthermore, when the lamp is not correctly connected to the HF ballast, the single switch device is also open, providing a safety creepage between the first and second ends. Again, when the lamp is correctly connected to the HF ballast, the switch device becomes closed, bypassing the converter so that the HF ballast can directly power the LEDs. All of these requirements are implemented by this single switch device.

[0011] According to an example according to an aspect of the present invention, a retrofit tubular lamp configured for use with both a first type of power source and a second type of power source is provided.

[0012] The retrofit tubular lamp comprises an input interface including a first end and a second end, both configured to be connectable to a first type of power source to receive power from the first type of power source, the first end of the input interface further configured to be connectable to a second type of power source to receive power from the second type of power source; a converter; a light emitting device; and a single switch device configured to be operable in at least a first switching state and a second switching state, wherein when operating in the first switching state and the first type of power source is connected to the input interface, the single switch device provides a first current path between the first and second ends of the input interface and supplies power to the light emitting device while isolating the converter from the light emitting device, and when operating in the second switching state and the second type of power source is connected to the first end of the input interface, the single switch device supplies power to the light emitting device via the converter and creates a safety creepage between the first and second ends of the input interface.

[0013] The proposed approach selectively uses a single switch device to connect two ends of an input interface of a retrofit tubular lamp to each other, the single switch device connecting the two ends bypassing the converter and the single switch device disconnecting the two ends providing a safety creepage between the two ends (while also allowing the converter to receive power and power the light emitting device).

[0014] Creepage is a measure or size of the (non-conductive or insulating) clearance between two electrical components (i.e. conductive components) or nodes and may be measured in mm. Creating a safety creepage may essentially involve creating a clearance (of insulating material) between two components or nodes that exceeds a predefined value. In other words, a safety creepage may be a creepage that exceeds a predefined threshold. Said safety creepage thereby provides a physical separation to prevent or reduce the possibility of electric shock. Preferably, said safety creepage is at least 1.5mm.

[0015] The embodiments provide a retrofit tubular lamp with enhanced safety (e.g., for the user during installation) by allowing the converter to operate when a second type of power source is connected to the lamp (single-ended input scenario) and at the same time preventing the converter from powering the light-emitting device when a first type of power source is connected to the lamp. The proposed approach implements these three operations using a single switch device, thereby simplifying the lamp's circuitry and minimizing the lamp's cost and material costs.

[0016] The light emitting device is preferably an LED light emitting device, ie a light emitting device comprising one or more LEDs.

[0017] The first type of power source may provide high frequency (e.g. >30kHz) power supply at the first and second ends of the input interface, and the second type of power source may provide low frequency (e.g. <100Hz or <120Hz) power supply at (only) the first end of the input interface.

[0018] In an embodiment, the retrofit tubular lamp is further configured to create a safety creepage between the second end and the first end when the single switch device operates in the second switching state, optionally when the first type of power source is connected with an external impedance or when the second type of power source is connected to the first end. The single switch device may be configured to be in the second switching state by default when the retrofit tubular lamp is not powered. In this embodiment, the single switch device also creates a safety creepage to the first type of power source when an external impedance is connected, such external impedance being typically a human body. Thus, the single switch device further achieves a fourth function of pin safety for double-ended input scenarios.

[0019] In an embodiment, the input interface may have a rectifier at the first end, the input of the rectifier configured to be connectable to the first type of power source and the second type of power source, the first end may be the end that couples to the second type of power source, while the second end should not be capable of coupling to or designed for coupling to the second type of power source.

[0020] In some examples, an input of the converter is connected to an output of the rectifier and the light emitting device is connected to the output of the converter, and the single switch device has an input node connected to the output of the rectifier and an output node connected to the light emitting device, the switch device being configured to, when operating in the first switching state, allow current to flow between the input node and the output node, thereby providing the first current path and bypassing the converter, and when operating in the second switching state, prevent current from flowing between the input node and the output node, thereby enabling the converter to draw power.

[0021] In an alternative embodiment, the single switch device may comprise a switching relay having an input terminal connected to the output of the rectifier, a first output terminal connected directly to the light emitting device, and a second output terminal connected directly to the converter, the switching relay may be configured to connect the input terminal to the first output terminal when the single switch device is operating in the first switching state, and to connect the input terminal to the second output terminal when the single switch device is operating in the second switching state.

[0022] This embodiment improves the reliability of power path selection.

[0023] The retrofit tubular lamp may further comprise a driver for generating a driving voltage from the first type of power source connected to the first end and the second end. The changeover relay may be configured such that the single switch device operates in the second switching state when no driving voltage is supplied to the changeover relay.

[0024] In at least one example, the change-over relay has a contact portion movable between a first position and a second position, where in the first position the contact portion connects the input terminal to the first output terminal and in the second position the contact portion connects the input terminal to the second output terminal, and the driver portion is configured to control the position of the contact portion and is coupled between the first end of the input interface and the second end of the input interface. The driver portion may be configured to draw sufficient power to generate the drive voltage to control the position of the contact portion when there is no external impedance connected to the input interface and to not draw sufficient power to generate the drive voltage to control the position of the contact portion when there is an external impedance connected to the input interface.

[0025] In this embodiment, when there is an external impedance to the power input at both ends, there is not enough power to drive the switch to close the path between the two ends with a low impedance, and therefore there is no large current through the external impedance / human body, thereby protecting the human.

[0026] The actuator may include a coil configured to control the position of the contact portion, and a safety capacitor arrangement connected in series with the coil, the safety capacitor having a suitable impedance sufficient to draw sufficient current from the HF ballast to limit current flow from electrocuting a human body when a human body is present, to disable actuator actuation of the coil, and to close the coil when a human body is absent.

[0027] In at least one example, the single switch device includes a switch input terminal connected to the output of the rectifier, a first switch output terminal connected directly to the light emitting device, a second switch output terminal connected directly to the converter, and a dip switch or relay connected to the switch input terminal and having a switching unit controllable between at least a first switching unit position, a second switching unit position, and a third switching unit position, where in the first switching unit position, the switching unit connects the switch input terminal to the first switch output terminal, thereby operating the single switch device in the first switching state, in the second switching unit position, the switching unit connects the switch input terminal to the second switch output terminal, thereby operating the single switch device in the second switching state, and in the third switching unit position, the switching unit is disconnected from both the first switch output terminal and the second switch output terminal. The dip switch or relay may be a center-off switch, such as a double pole, center-off switch. This embodiment provides a manual configuration method.

[0028] In an embodiment, the single switch device may be configured such that a creepage distance between the switching portion and the first switch output terminal when in the third switching portion position is greater than a predetermined threshold, optionally greater than 1.5 mm.

[0029] In some examples, the light emitting device comprises a plurality of light emitting units and a reconfiguration circuit configured to configure the light emitting units to be connected in series when the single switch device operates in the first switching state, and to configure the light emitting units to be connected in parallel when the single switch device operates in the second switching state. In other words, when the lamp is powered by the first type of power source (e.g., high frequency), the light emitting units are in parallel, otherwise, when the lamp is powered by the second type of power source (e.g., low frequency), the light emitting units are in series. There is a use case of two lamps connected in series with an AC mains power source. The inventor has realized that by having a series-connected light emitting unit in each lamp, powered by the converter, it can improve the unity of the light output of different lamps. Preferably, this is determined by the intrinsic characteristics of the converter.

[0030] The retrofit tubular lamp may further include a linear regulator connected between the converter and the light emitting unit for the second type of power source, and optionally, the linear regulator is disconnected from the first current path between the first end and the second end of the input interface for the first type of power source. Therefore, the linear regulator may only be in the power path for the second type of power source. In this way, it can reduce low frequency ripple caused by the second type of power source, while not interfering with the first type of power source at high frequency. Therefore, a double advantage can be provided.

[0031] In at least one example, the first type of power source is a high frequency power source / ballast configured to power a fluorescent lamp, and the second type of power source is a low frequency power source, optionally including a low frequency ballast or mains power source configured to power a fluorescent lamp. The high frequency may be a frequency greater than 1 kHz, e.g., greater than 10 kHz, e.g., greater than 30 kHz. The low frequency may be a frequency less than 1 kHz, e.g., less than 120 Hz / 100 Hz, e.g., the mains frequency.

[0032] In some examples, the retrofit tubular lamp is configured such that the rectifier device at the first end of the input interface has a positive rectified output node and a negative rectified output node, the tubular lamp further has a further rectifier device at the second end of the input interface including a further positive node and a further negative node, and the single switch device has first and second switching elements that are operated as a whole.

[0033] The single switch device is configured to operate in the first switching state to control the first switching element to connect the positive rectified output node to the further positive node of the second end of the input interface and to control the second switching element to connect the negative rectified output node to the further negative node of the second end of the input interface when a power source of the first type is connected to the input interface, and to operate in the second switching state to control the first switching element and the second switching element to decouple the positive rectified output node and the negative rectified output node from the further positive node and the further negative node of the second end of the input interface when a power source of the second type is connected to the input interface.

[0034] The above embodiments provide detailed examples of the lamp.

[0035] As mentioned above, in order to provide uniformity of light output of different lamps connected in series with an AC mains power supply, it is desirable to set the operation of the converter to a high output voltage so that the output current of the converter is more uniform with the other lamps. To achieve this, in another aspect of the present invention, a tubular LED lamp is proposed, comprising an LED device, a first end and a second end, the first end being adapted to connect to a low frequency power supply and the first end and the second end being adapted to connect to a high frequency power supply, the tubular LED lamp having a control circuit adapted to detect whether the power supply is received at the first end or between the first end and the second end, to configure the LED device in a first mode with series LEDs when the power supply is received at the first end but not between the first end and the second end, and to configure the LED device in a second mode with parallel LEDs when the power supply is received between the first end and the second end.

[0036] Prior art EP3050399B1 detects the frequency of the input and configures LEDs in series or parallel depending on whether the detected frequency is an HF ballast frequency or an EM ballast frequency. The above aspect of the present invention differs from the prior art in that it detects whether power is coming from only the first end or from both ends and configures LEDs in series or parallel depending on whether power is coming from only the first end or from both ends.

[0037] In a detailed embodiment, the tubular LED lamp further comprises a pin safety switch in series with the LED device between the first end and the second end, and a bypass capacitor in parallel with the safety switch (this is already known and there is a lot of prior art), and together with the bypass capacitor, the control circuit is adapted to configure the LED device in the second mode when either a low-frequency or high-frequency power source is connected between the first end and the second end. In this embodiment, the control circuit is a wideband frequency driver that responds to both low-frequency and high-frequency power sources as long as they are between the first end and the second end. This makes the configuration of the tubular LED lamp not determined by the frequency of the input, but only dependent on whether the input is via the first end only or via both ends.

[0038] In a further embodiment, the control circuit is adapted to set the LED device to the first mode by default and change the LED device to the second mode in response to a power source between the first end and the second end.

[0039] In an alternative third aspect, instead of detecting whether the power source is coming in via a single end or via both ends, it is proposed to detect the amplitude of the voltage on the bus to identify whether the input is AC mains or an HF ballast. More specifically, a retrofit tubular lamp adapted for use with both a first type of power source and a second type of power source, an input interface including a first end and a second end, both configured to be connectable to a first type of power source to receive power from the first type of power source, the first end of the input interface further configured to be connectable to a second type of power source to receive power from the second type of power source; A converter; an LED device coupled to the converter; a bypass switch adapted to bypass or not bypass the converter depending on the frequency of the input, A retrofit tubular lamp is proposed, characterized in that it further comprises a voltage detector adapted to detect the voltage in front of the bypass switch and to change the LED arrangement to series LEDs or parallel LEDs depending on said voltage.

[0040] These and other aspects of the invention will be elucidated and elucidated with reference to the following embodiments. [Brief description of the drawings]

[0041] For a better understanding of the present invention, and to show more clearly how the same may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which: [Figure 1] 1 illustrates a known retrofit tubular lamp configured for a first type of power source and a second type of power source; [Diagram 2] 1 illustrates a driver for a retrofit tubular lamp. [Diagram 3] 1 illustrates a switch driver for use with a driver for the retrofit tubular lamp. [Figure 4] 1 illustrates a driver for the retrofit tubular lamp. [Diagram 5] 1 illustrates a driver for the retrofit tubular lamp. [Figure 6] 1 illustrates a light emitting device for the retrofit tubular lamp. [Figure 7] 1 illustrates a light emitting device for the retrofit tubular lamp. [Figure 8] 1 illustrates a light emitting device for the retrofit tubular lamp. [Figure 9] 2 illustrates a circuit diagram of a tubular LED lamp according to a second embodiment of the present invention, which is an improvement over the lamp shown in FIG. [Figure 10]10 illustrates an example of a control circuit for switch SW1 in the embodiment of FIG. 9. [Figure 11] 10 illustrates an example of a control circuit for switch SW2 in the embodiment of FIG. 9. [Figure 12] 2 illustrates a circuit diagram of a tubular LED lamp according to a third embodiment of the present invention, which is an improvement over the lamp shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The present invention will be described with reference to the drawings.

[0043] It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the devices, systems and methods, are for purposes of illustration only and are not intended to limit the scope of the invention. These and other features, aspects and advantages of the devices, systems and methods of the present invention will become better understood from the following description, appended claims and accompanying drawings. It should be understood that the figures are merely schematic and are not drawn to scale. It should also be understood that the same reference numerals are used throughout the figures to denote the same or similar parts.

[0044] The present invention provides a retrofit tubular lamp. The single switch device is configured to selectively connect a first end and a second end of an input interface to each other. When the two ends are connected, the converter is bypassed while power between both ends (i.e., two-end power) is supplied to a light-emitting device of the lamp. When the two ends are disconnected, power is supplied to the light-emitting device through the converter at the single end. The single switch device is further configured such that when the two ends are disconnected from each other, a creepage distance between the two ends is equal to or greater than a predetermined safety distance (i.e., a safety creepage is created). In short, both the bypass function and the safety creepage function are provided by the single switch device.

[0045] FIG. 2 illustrates a first configuration of a driver 200 for a retrofit tubular lamp according to an embodiment.

[0046] The driver 200 is configured to drive a light emitting device (not shown) formed of an LED, regardless of whether the driver is powered by a first type of power supply or a second type of power supply.

[0047] As explained above, the first type may be a high frequency power supply designed for powering fluorescent lamps (i.e. including a high frequency ballast) and the second type may be a low frequency power supply including at least an AC mains supply or a low frequency ballast. Thus, the first type of power supply may provide high frequency power (e.g. >30kHz) and the second type of power supply may provide low frequency power (e.g. <120Hz / 100Hz such as mains frequency).

[0048] The driver has an input interface including a first end 211 and a second end 212. The first end 211 has a first input node Pin1 and a second input node Pin2. The second end 212 has a third input node Pin3 and a fourth input node Pin4 that are connected together. There may be additional filament circuits at the first end 211 and the second end 212, which are for compatibility with HF ballasts. These filament circuits are not relevant to the present invention and are therefore omitted.

[0049] The first end 211 and the second end 212 are both configured to be connectable to a first type of power source to receive power from the first type of power source. The first end of the input interface is further configured to be connectable to a second type of power source to receive power from the second type of power source. These are two typical installations of this lamp, especially in the European region. The user needs to be instructed not to connect the second end to a second type of power source. To reduce the risk of such an incorrect connection, there needs to be a label on the lamp or the protection circuit. In any case, this is also not relevant to the present invention and therefore will not be shown in further detail.

[0050] Thus, when the driver is connected to a first type of power source, power is provided at both ends of the input interface, also referred to as a double-ended input. When the driver is connected to a second type of power source, power is provided only at the first end of the input interface, also referred to as a single-ended input.

[0051] The driver further comprises a rectifier 221 formed of a number of diodes D1, D2, D3, D4. The rectifier 221 provides a positive rectified output node V+ and a negative rectified output node V-. The rectifier is configured such that only positive voltages can flow from the first end 211 to the positive rectified output node and only negative voltages can flow from the first end 211 to the negative rectified output node. Here, the rectifier is a bridge rectifier.

[0052] The driver 200 further comprises a further rectifier 222. The further rectifier is formed of a number of diodes D5, D6. The further rectifier has a further positive node Vf+ and a further negative node Vf-. The further rectifier is configured such that only positive voltages can flow from the second end 212 to the further positive node Vf+ and only negative voltages can flow from the second end 212 to the further negative node Vf-.

[0053] The driver further comprises a converter 250. The converter may be a switched mode power supply or other form of AC / DC-DC converter and may comprise a buck converter, a boost converter and / or a buck-boost converter. In Figure 1 an example of a suitable buck converter is shown.

[0054] The converter 250 is configured to convert power Vin provided at converter input nodes Vi+, Vi- to generate DC power Vo at first voltage supply nodes Va+, Va- for powering a light emitting device. In this first configuration of the driver, the converter input nodes Vi+, Vi- are directly connected to the rectified output nodes V+, V-.

[0055] The driver 200 further comprises a single switch device SW1 (which may be a relay with integrated double contacts SW1a, SW2a). The single switch device operates to selectively bypass the converter 250 by closing the switch device. When the converter is bypassed (by the single switch device), the light-emitting device is powered by the second voltage supply nodes Vb+, Vb-. Vb+ is directly connected to Vf+ and Vb- is directly connected to Vf-. When the converter is not bypassed, the light-emitting device is powered by the first voltage supply nodes Va+, Va- provided by the converter 250.

[0056] There are therefore two sets of voltage supply nodes for the light emitting device: a first set including first voltage supply nodes Va+, Va- and a second set including second voltage supply nodes Vb+, Vb-.

[0057] The single switch device is shown diagrammatically using separate sub-switches, but in practice may be integrated into a single device such as a dual contact relay or a double pole single throw switch.

[0058] The single switch device is operable in at least a first switching state and a second switching state.

[0059] When operating in a first switching state and a first type of power source is connected to the input interface, the single switch device is configured to provide a first current path between the first end and the second end of the input interface and supply power to the light-emitting device while decoupling the converter from the light-emitting device.

[0060] In the illustrated example, a single switch device is closed to connect the positive rectified output node V+ to a further positive node Vf+ (and therefore to Vb+) and the negative rectified output node V- to a further negative node Vf- (and therefore to Vb-).

[0061] In this manner, when the single switch device is operating in a first switching state and a first type device is connected to the input interface (at the first end and the second end), if the power is positive at the first end 211, the current flows from Pin1-Pin2 through the diodes D1-D2 to Vb+ which connects to the light emitting device, then to Vb-, through D6, and finally to the second end 212, and if the power is positive at the second end, the current flows from Pin3 / Pin4 through the diodes D5 to Vb+ which connects to the light emitting device, then to Vb-, through D3-D4, and finally to the second end Pin1-Pin2. In this case, the converter 250 is in a non-operating state or condition.

[0062] In this manner, when the single switch device is operating in a first switching state, the second set of voltage supply nodes Vb+, Vb- provides a voltage supply for the light emitting device.

[0063] When operating in a second switching state and a second type of power source is connected to the first end of the input interface, the single switch device is configured to supply power to the light-emitting device through the converter and create a safety creepage surface between the first end and the second end of the input interface.

[0064] In this manner, when the single switch device is operating in a second switching state and a second type device is connected to the input interface (at a first end), if Pin1 is positive, current flows from Pin1, through diode D1, to converter 250 at node Vf+, whereby converter 250 supplies a voltage at Va+ / Va- to power the connected light-emitting device, and back to diode D4 and Pin2 at node Vf-, and vice versa if Pin2 is positive.

[0065] Thus, in this approach, when the single switch device is operating in the second switching state, the first set of voltage supply nodes Vb+, Vb- provides a voltage supply for the light emitting device.

[0066] Since the switch is open, a safe creepage is obtained when the creepage distance between the first and second ends of the input interface (i.e., between the contacts of a single switch device) is greater than a predetermined safety distance, for example 1.5 mm. This can be achieved through the use of a suitably configured switching device, for example a dual contact relay. Thus, a person touching the second end when installing the first end into a socket will be electrically connected to the power supplied at the first end and is therefore safe.

[0067] The proposed approach effectively combines the functionality of a bypass switch with pin safety by using a single switch device to provide safety creepage when operating in the second switch state, which simplifies the circuitry of retrofit tubular lamps.

[0068] The operation of the single switch device may be controlled by a switch driver (not shown). The switch driver may be configured to close the switch to connect the first and second ends of the input interface together when high frequency power is provided to the input interface (i.e., the first type of power source provides power) and to disconnect the first and second ends when there is no or insufficient high frequency power provided between the first and second ends (for safety creepage in a double-ended input scenario). More specifically, the switch driver may connect to both ends and detect whether there is sufficient AC signal flowing between both ends. If there is sufficient AC signal, meaning that the HF ballast may be connected correctly, the switch driver closes the switch to bypass the converter and allow the LED device to be powered by the first type of power source, otherwise the switch driver keeps the switch open to create a safety creepage between the two ends while allowing the converter to be powered by a potential second type of power source at the first end. Thus, the switching state of the single switch device may depend on the type of power source connected to the input interface.

[0069] FIG. 3 illustrates an example of a switch driver 300 for controlling a single switch device SW1.

[0070] Here, the single switch device SW1 is a change-over relay having two input terminals and two output terminals. The change-over relay has contacts movable between a first position in which the input terminals are disconnected from the output terminals, and a second position in which each input terminal is connected to a respective output terminal. SW1 is therefore a double-pole single-throw switch.

[0071] One input terminal is connected to the positive rectified output node V+ and controllably connects to an output terminal connected to Vb+, and another input terminal is connected to the negative rectified output node V− and controllably connects to an output terminal connected to Vb−.

[0072] A driver controls the position of the contacts and may include a coil configured to connect the input terminal to the output terminal (when sufficient voltage is applied) and may otherwise (i.e., in an unpowered state) disconnect the input terminal from the output terminal.

[0073] When the input and output terminals of a single switch device SW1 are separated, the creepage distance d c is configured to be equal to or greater than the (minimum) safety distance, for example, 1.5 mm or greater. Other safety distances will be described later.

[0074] Switch driver 300 controls the voltage supplied to the driver of a single switch device SW1.

[0075] The switch driver 300 is powered by high frequency AC current provided at Pin1 / Pin2, Vb-, and Pin3 / 4. This current passes through a switch rectifier (including diode D52). The rectified power is smoothed by smoothing capacitor C6 to provide DC power at switch control node Coilp. The DC power across C6 drives switch relay SW1.

[0076] Ground resistor R2 is configured to provide a path for the rectified power to ground (at Vb-). Diode D20 prevents the voltage at switch control node Coilp from falling below the voltage at Vb-.

[0077] A respective Y-capacitor Y2, Y3 is connected in series with each pin Pin1, Pin2. The capacitance of these capacitors is selected to limit the charging current. The appropriate selection of the capacitance means that the driver of the single switch device is powered only when high frequency power is provided at pins Pin1 / Pin2 and Pin3 / Pin4, optionally without any human body impedance, so that pin safety for the high frequency ballast can be obtained.

[0078] In summary, the operating principle of the single switch device SW1 and switch driver is that when a first type of power supply provides (high frequency) power at both ends, the capacitor has a low / appropriate impedance and there is enough power to drive SW2 (i.e. the circuit is closed), and when a second type of power supply provides (low frequency) power at pins Pin1, Pin2, the capacitor has a high impedance and prevents the occurrence of a short circuit between pins Pin1 and Pin2.

[0079] The improvement of pin safety can be realized by suitable setting of the (impedance of) capacitors Y2, Y3. In particular, the impedance of the human / body R is external to Pin3 / Pin4 of the second end of the input interface (connected to Vb− for example). H If there is a capacitor, R H and the combined impedance of the driver of the single switch device can be configured to be so large that the driver does not receive enough voltage (i.e., the voltage at Coilp is insufficient to operate the driver). Therefore, switch SW1 does not close, which prevents large currents from flowing through the input interface and the human body, improving human safety when touching. Of course, in the absence of human / body impedance, the combined impedance of the capacitor and the driver of the single switch device is sufficient to operate the driver of the single switch device to close switch SW1.

[0080] FIG. 4 illustrates a second configuration of a driver 400 for a retrofit tubular lamp according to an embodiment.

[0081] The driver 400 differs from the previously described driver 200 in the configuration of the single switch device SW2 and the surrounding terminal connections.

[0082] The single switch device SW2 comprises a double-pole, double-throw switch. The single switch device SW2 is formed from a first sub-switch SW2a and a second sub-switch SW2b. The first sub-switch SW2a controllably connects V+ to either Vi+ (no longer directly connected to V+) or Vb+, and the second sub-switch SW2b controllably connects V- to either Vi- (no longer directly connected to V-) or Vb-.

[0083] The operation of the driver 400 is substantially the same as that of the driver 200 described above, except that when the converter is bypassed (i.e., when V+ is connected to Vb+ and V- is connected to Vb-), the converter is no longer connected to the output of the rectifier (i.e., the converter is completely disconnected). Thus, the second switching state is modified such that, rather than simply disconnecting the first end from the second end, the first end is disconnected from the second end and connected to (the input of) the converter. Similarly, the second switching state is modified such that, rather than simply connecting the first end to the second end, the first end is connected to the second end and disconnected from the converter.

[0084] Therefore, the operating principle of the driver 400 is as follows.

[0085] When the single switch device SW2 is operating in a first switching state and a first type of device is connected to the input interface, the switches SW2a / b switch to the Vb+ / - position, and current flows between the first end and the second end through Pin1-Pin4, through the diodes D1-D6, and through Vb+ / Vb- which connects to the light emitting device. In this case, the converter 150 is disconnected from the rectifier so that the input nodes Vi+, Vi- are floating or high impedance.

[0086] When the single switch device SW2 is operating in a second switching state and a second type of device is connected to the first end of the input interface, the switches SW2a / b are in the position shown and current flows via Pin1 and Pin2 through the diodes D1-D4 to the converter 450, whereby the converter 450 provides a voltage at Va+ / Va- for powering the connected light emitting device. In this case, the converter is connected to the output of the rectifier device and the second end of the interface is disconnected from the first end of the interface.

[0087] When in the second switching state, the single switch device SW2 is configured such that the creepage distance (between the first end and the second end) is greater than a predetermined safety distance (e.g., 1.5 mm). In other words, a safety creepage is provided.

[0088] Because the converter 450 is no longer connected to the output of the rectifier when it is bypassed when the first type of power source is connected, the converter 450 is not at risk of being triggered by the non-lighting voltage of the first type of power source, and considerations regarding the converter's construction (e.g., whether to use a buck converter or a boost converter) no longer need to be considered. Thus, the configuration of the driver 400 of FIG. 4 offers more flexibility than the driver 200 of FIG. 2. However, the single switch device of the first configuration (double pole single throw) is simpler, more cost effective, and uses less material than the single switch device of the second configuration.

[0089] The configuration and operation of the switch driver for driver 400 in FIG. 4 may be the same as that shown in FIG. 3, except that the switch is configured to connect the first end of the interface to the converter 450 (rather than simply floating) when the switch is not powered to connect the first end of the interface to the second end of the interface.

[0090] The switch driver and the switch may be configured such that when the driver is not powered, the switch connects V+ to Vi+ and V- to Vi-. This increases safety for a person installing or fitting a retrofit tubular lamp, for example, since no current is allowed to flow from the first end of the input interface to the second end of the input interface during installation (e.g., when a mains power supply is connected to the first end of the input interface).

[0091] FIG. 5 illustrates a third configuration of a driver 500 for a retrofit tubular lamp according to an embodiment.

[0092] The driver 500 differs from the first and second configurations 100 and 400 in the configuration and surrounding terminal connections of the single switch device SW3.

[0093] The single switch device SW3 has a two-pole change-over switch or a two-pole center-off switch. The single switch device SW3 is formed of a first sub-switch SW3a and a second sub-switch SW3b. The first sub-switch SW3a controllably connects V+ to Vi+ (no longer directly connected to V+) or to nothing (i.e., floating). The second sub-switch SW3b controllably connects V- to Vi- (no longer directly connected to V-) or to nothing (i.e., floating).

[0094] Therefore, the operating principle of driver 500 is similar to driver 400. However, the single switch device is further operable in a third switching state, in which the single switch device decouples converter 550 from the input interface and decouples the first end of the input interface from the second end.

[0095] Since in the third switching state there is no electrical connection (ie no current flows) between the input and output of the driver 500, the third switching state can increase safety during installation of retrofit tubular lamps.

[0096] Thus, the single switch device SW3 has a switching portion movable between three switching positions: a first switching position (wherein the switching portion connects V+ to Vb+ and V- to Vb-), a second switching position (wherein the switching portion connects V+ to Vi+ and V- to Vi-), and a third switching position (wherein V+ is disconnected from Vb+ and Vi+ and V- is disconnected from Vb- and Vi-).

[0097] Preferably, the single switch device SW3 is configured such that when the switching section is in the third switching position, the creepage distance between the first end and the second end of the input interface is greater than or equal to a predetermined safety distance (e.g., ≧1.5 mm).

[0098] The single switch device SW3 may be a manually operated switch and may not be associated with a switch driver, for example as in the example of a single switch device in the first and second configurations of the driver.

[0099] In another example, a single switch device may be based on input detection (ie, detection of the type of power source connected to the input interface).

[0100] In all the above configurations of the retrofit tubular lamp driver, there are two sets of voltage supply nodes for the light emitting device. The switching state of a single switch device, and therefore the type of power supply, controls which set provides the voltage supply to the light emitting device. Therefore, it is easy to realize different light output devices depending on the set of voltage supply nodes used (and therefore depending on the type of power supply).

[0101] Therefore, the proposed configuration of a retrofit tubular lamp driver, each having two sets of voltage source nodes, offers new opportunities for configuring and controlling light emitting devices.

[0102] FIG. 6 illustrates a first configuration of a light emitting device 600 for a retrofit tubular lamp.

[0103] The light emitting device 600 is configured to receive power from either a first set of voltage source nodes Va+, Va- or a second set of voltage source nodes Vb+, Vb-.

[0104] The light emitting device 600 comprises two LED sets (each including one or more LEDs), a first LED set LEDs1 and a second LED set LEDs2. Each LED set may comprise (a part of) a tubular LED. The light emitting device 600 further comprises a diode arrangement, comprising diodes D8, D13, D14, D15 and D16.

[0105] The diodes are configured such that when power is received from a first set of voltage source nodes Va+, Va−, the first LED set LEDs1 and the second LED set LEDs2 are connected in series (i.e., current flows through the first set and then through the second set), and the diodes are also configured such that when power is received from a second set of voltage source nodes Vb+, Vb−, the first LED set LEDs1 and the second LED set LEDs2 are connected in parallel (i.e., current is divided between the first and second sets).

[0106] The diodes therefore act as a reconfiguration circuit to configure the set of LEDs to be connected in series or in parallel.

[0107] Therefore, the proposed driver for retrofit tubular lamps, providing two sets of voltage supply nodes for the light emitting device, eliminates the need for an additional switch in the light emitting device to define whether the LED sets are connected in series or in parallel, which makes the series-parallel connection change easier to implement, improves the reliability of said change (by avoiding the use of switches) and reduces the (material) costs.

[0108] Those skilled in the art will understand how diodes D8, D13, D14, D15, and D16 can be replaced with a suitable switch device, such that the suitable switch device can function as a reconstruction circuit.

[0109] FIG. 7 illustrates a second configuration of a light emitting device 700 for a retrofit tubular lamp.

[0110] FIG. 7 illustrates how a ripple remover 750 (e.g., including a linear regulator and / or other similar circuit) can be added to smooth the currents supplied at the first set of voltage supply nodes Va+ / - without smoothing the currents supplied at the second set of voltage supply nodes (i.e., it can be disabled or bypassed).

[0111] This method reduces the low-frequency ripple of the second type of power source, which is low in frequency. In addition, avoiding the ripple remover from being active when the first type of power source powers the retrofit tubular lamp can prevent the power loss of the first type of power source and the occurrence of conflicts between the ripple remover and the first type of power source, such as conflicts between the linear regulation of slow response and spike ignition voltage. By using the ripple remover, it is not necessary to use a large output capacitor for the second type of power source, which can help reduce the afterglow when the retrofit tubular lamp is turned off when the second type of power source is used. From another angle, since the frequency of the first type of power source is very high and cannot be sensed by humans, it is not necessary to use a large output capacitor for the first type of power source. Overall, a large output capacitor is not used and afterglow is prevented.

[0112] The use of two sets of voltage source nodes eliminates the need for additional switching circuitry or the like to control whether the ripple filter is active or not.

[0113] The concepts shown in the second configuration can be easily adapted for use in the first configuration of the light emitting device, for example through appropriate placement of a ripple eliminater (e.g. between Va- and the second set of LEDs).

[0114] FIG. 8 illustrates yet another configuration for a light emitting device 800 for a retrofit tubular lamp.

[0115] The light emitting device provides two separate LED sets (of one or more LEDs): the first LED set LEDs1 is driven when power is provided at the voltage supply nodes Va+, Va- of the first set; the second LED set LEDs2 is driven when power is provided at the voltage supply nodes Vb+, Vb- of the second set; otherwise, no LED set is driven.

[0116] Preferably, in this example, the light emitting device 800 has a creepage distance d between V+, Vb+, V−, Vb−, and between the first LED set and the second LED set. c is configured to be a predetermined safety distance, for example, 1.5 mm or more.

[0117] In some examples, a ripple eliminater may be connected in series with the first LED set LEDs1 and / or a ripple eliminater may not be connected in series with the second LED set LEDs2. This approach shortens the period of afterglow when the first power source (connected to the input interface) stops supplying power to the retrofit tubular lamp.

[0118] In any of the described embodiments, the retrofit tubular lamp may have more than two LED sets, and any reconstruction circuitry, if present, may be configured to connect the LED sets in any configuration (e.g., in series or parallel). In any of the described embodiments, the LED sets may be replaced with other forms of lighting units, for example, halogen-based lighting units.

[0119] In any of the above embodiments, the single switching device is preferably an electromechanical switch, such as a relay, etc. In a particular example, the single switching device is configured such that the creepage distance between any input terminal and any output terminal of the single switching device is equal to or greater than a predetermined safety distance (e.g., 1.5 mm).

[0120] The predetermined safety distance (e.g., 1.5 mm) of the creepage distance in the above example is merely exemplary and may vary depending on (for example) best practices, industry standards, altitude or barometric pressure changes, and / or desired safety margins. Other suitable examples of the predetermined safety distance include 1 mm, 2 mm, 3 mm, 5 mm, 10 mm, etc.

[0121] In another aspect of the present invention, a tubular LED lamp is proposed that configures the LEDs in series or parallel connection depending on whether the input is received at only one end or between two ends. As mentioned above, there are use cases where it is desirable to connect the tubular LED lamps in series with AC mains to achieve uniformity of light output between the lamps. It is noted that connecting the tubular LED lamps in series with AC mains means that Pin1 and Pin2 of the two lamps are connected in series with AC mains while Pin3 and Pin4 of each lamp are still float. Converters are needed because each lamp is powered by AC mains (low frequency power). The inventors have noticed that the converters of the different lamps will regulate their output current more uniformly when the converter output voltage is high. Thus, the inventors propose to detect whether the input is coming in through a single end or both ends and configure the LEDs in series if the input is coming in through a single end and configure the LEDs in parallel if the input is coming in through both ends.

[0122] Figure 9 shows an implementation of the above embodiment on top of the known circuit shown in Figure 1. Components that are similar between Figure 9 and Figure 1 will not be described again.

[0123] Most importantly, a tubular LED lamp is proposed, comprising an LED device, a first end 111 and a second end 112, the first end 111 being adapted for connection to a low frequency power source and the first end 111 and the second end 112 being adapted for connection to a high frequency power source, the tubular LED lamp having a control circuit adapted to detect whether power is received at the first end 111 or between the first end 111 and the second end 112, and to configure the LED device in a first mode having series LEDs when the power is received at the first end 111 but not between the first end 111 and the second end 112, and to configure the LED device in a second mode having parallel LEDs when the power is received between the first end 111 and the second end 112.

[0124] The control circuit has two switches SW1 and SW2 and respective drive circuits, as shown in Fig. 9. When the input is detected to be via the first end only, the switches SW1 and SW2 are open, and the LEDs1 and LEDs2 are connected in series and driven by a buck converter including the switch M1, the inductor L1 and the diode D32; when the input is detected to be via the first end 111 and the second end 112, the switches SW1 and SW2 are closed, and the LEDs1 and LEDs2 are connected in parallel, and optionally the buck converter is bypassed by a MOSFET Bypass so that the input directly powers the parallel LEDs1 and LEDs2.

[0125] Figure 10 shows a control circuit including a switch SW1 and its driver. The detection of whether the input comes through both ends is via terminals V+ and X1, which are also shown in Figure 9. Terminal V+ is substantially connected to the first end via a rectifier diode, and terminal X1 is substantially connected to the second end via a Y capacitor.

[0126] When only the first end 111 is connected to the power supply, there is no electrical path from the terminal V+ to the terminal X1, therefore the capacitor C12 is not charged and the switch SW1 is not driven to close, therefore the switch SW1 is open.

[0127] When the power supply is connected to both the first end 111 and the second end 112, the power supply is an AC power supply and there is current flowing from the first end 111, terminal V+, diode D18, capacitor C11, resistor R12, terminal X1, the Y capacitor to the second end 112 to charge the capacitor C12. Preferably, the capacitance of the Y capacitor and capacitor C11 allows the HF ballast frequency and the AC mains / EM ballast frequency to pass through and charge the capacitor C12. The switch SW1 is a PMOS, so the source-to-gate bias voltage provided by the capacitor C11 can close the switch SW1.

[0128] Figure 11 shows a control circuit including the switch SW2 and its driver. The detection of whether the input comes through both ends is through terminals V- and X1, which are also shown in Figure 9. Terminal V- is substantially connected to the first end through a rectifier diode, and terminal X1 is substantially connected to the second end through a Y capacitor.

[0129] When only the first end 111 is connected to the power supply, there is no electrical path from the terminal V- to the terminal X1, therefore the capacitor C12 is not charged and the switch SW2 is not driven to close, therefore the switch SW2 is open.

[0130] When a power source is connected to both the first end 111 and the second end 112, the power source is an AC source and there is current flowing from the second end 112, the Y capacitor, terminal X1, resistor R7, capacitor C2, diode D16, terminal V- to the first end 111 to charge capacitor C10. Preferably, the capacitance of the Y capacitor and capacitor C10 allows the HF ballast frequency and the AC mains / EM ballast frequency to pass through and charge capacitor C12. Switch SW2 is an NMOS, so the gate-to-source bias voltage provided by capacitor C10 can close switch SW2.

[0131] When the switches SW1 and SW2 are open, the LEDs1 and LEDs2 are connected in series, and when the switches SW1 and SW2 are closed, the LEDs1 and LEDs2 are connected in parallel.

[0132] When the pin safety circuit is closed with a sufficient signal from the HF ballasts connected to both ends, the Y capacitor is bypassed and current is still present to charge capacitors C10 and C11 to keep switches SW1 and SW2 closed.

[0133] In an alternative third embodiment, as shown in FIG. 12, there is provided a retrofit tubular lamp configured for use with both a first type of power source and a second type of power source, an input interface including a first end and a second end, both configured to be connectable to a first type of power source to receive power from the first type of power source, the first end of the input interface further configured to be connectable to a second type of power source to receive power from the second type of power source; A converter; an LED device coupled to the converter; a bypass switch adapted to bypass or not bypass the converter depending on the frequency of the input, A retrofit tubular lamp is proposed, characterized in that it further comprises a voltage detector adapted to detect the voltage before the bypass switch and to change the LED arrangement to series LEDs or parallel LEDs depending on the voltage.

[0134] More specifically, when an HF ballast is connected, the bypass switch is closed (via high frequency selection between the two ends), bypassing the buck converter, and the HF ballast signal flows directly to the LED, with the voltage amplitude before the bypass switch Bypass being equal to the relatively low LED forward voltage.

[0135] When the AC mains is connected, the bypass switch is open and the buck converter connects to the AC mains, and the voltage before the bypass switch Bypass is substantially the input voltage, i.e., the peak is 230*1.414 volts for a single lamp installation and 115*1.414 volts for a series lamp installation, both of which are significantly higher than the LED forward voltage in the HF case.

[0136] Then, if the detected voltage is low, the LED devices are set to parallel connection, and if the detected voltage is high, the LED devices are set to series connection.

[0137] Those skilled in the art can understand and effect variations to the disclosed embodiments in the practice of the claimed invention from a study of the drawings, the specification and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the singular does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. It should be noted that when the term "adapted to" is used in the claims or the description, the term "adapted to" is intended to be equivalent to the term "configured to". Any reference signs in the claims should not be interpreted as limiting the scope.

Claims

Claim 1: A retrofit tubular lamp configured to be used with either a first type of power supply or a second type of power supply at a time, An input interface including a first end and a second end, the retrofit tubular lamp being adapted to be connected to the first type of power supply through both the first end and the second end, and the retrofit tubular lamp being adapted to be connected to the second type of power supply through only the first end; an input interface, A converter coupled to the first end, The converter and a light emitting device coupled to the first end and the second end, A single switch device connected between the first end, the light emitting device and the second end, the single switch device being configured to be operable in at least a first switching state and a second switching state, Operating in the first switching state, when the first type of power supply is connected to the input interface, the single switch device provides a first current path between the first end and the second end of the input interface, and is configured to supply power to the light emitting device while disconnecting the converter from the light emitting device, and Operating in the second switching state, when the second type of power supply is connected to only the first end of the input interface, the single switch device supplies power to the light emitting device through the converter, and creates a safety creepage surface between the first end and the second end of the input interface such that the first end and the second end of the input interface are electrically disconnected. A retrofit tubular lamp having a single switch device.

2. Furthermore, when the single switch device is operating in the second switching state, optionally, when the first type of power supply is connected to an external impedance, or when the second type of power supply is connected to the first end, the retrofit tubular lamp according to claim 1, configured to create a safety creepage surface between the second end and the first end.

3. The input interface has a rectifier at the first end, and the input of the rectifier is configured to be connectable to the first type of power supply and the second type of power supply. The single switch device is adapted to disconnect the converter from the second end in the second switching state. The retrofit tubular lamp according to claim 1 or 2.

4. The tubular lamp further has a further rectifier at the second end of the input interface. The input of the converter is adapted to be connected to the output of the rectifier at the first end. The light emitting device is connected to the output of the converter. The single switch device has an input node connected to the output of the rectifier and an output node connected to the light emitting device. The light emitting device is connected to the further rectifier. The switch device. When operating in the first switching state, it allows current to flow between the input node and the output node, and thus allows current to flow between the first end and the second end, thereby providing the first current path, bypassing the converter, and When operating in the second switching state, it electrically disconnects the first end and the second end, preventing current from flowing between the input node and the output node, and thus preventing current from flowing between the first end and the second end, thereby enabling the converter to draw power. The retrofit tubular lamp according to claim 3.

5. The rectifier at the first end of the input interface has a positive rectified output node and a negative rectified output node. The tubular lamp further has a further rectifier at the second end of the input interface including a further positive node and a further negative node. The single switch device is a coil-operated relay and has a first switching element and a second switching element that are operated as a whole. The single switch device. When operating in the first switching state and when the first type of power supply is connected to the input interface, control the first switching element to connect the positive rectified output node to the further positive node at the second end of the input interface, control the second switching element to connect the negative rectified output node to the further negative node at the second end of the input interface, and When operating in the second switching state and when the second type of power supply is connected to the input interface, the retrofit tubular lamp according to claim 3, wherein the first switching element and the second switching element are configured to disconnect the positive rectified output node and the negative rectified output node from the further positive node and the further negative node at the second end of the input interface.

6. The single switch device has a switching relay having an input terminal connected to the output of the rectifier device, a first output terminal directly connected to the light emitting device, and a second output terminal directly connected to the converter, The switching relay is When the single switch device is operating in the first switching state, connect the input terminal to the first output terminal, and The retrofit tubular lamp according to claim 3, wherein when the single switch device is operating in the second switching state, the input terminal is connected to the second output terminal.

7. The switching relay has a driving part connected between the first end part and the second end part to generate a driving voltage from the first type of power supply connected to the first end part and the second end part. When the driving voltage is supplied to the switching relay, the single switch device operates in the first switching state. The retrofit tubular lamp according to claim 6.

8. The switching relay is configured such that when the driving part cannot generate the driving voltage from the first type of power supply connected to the first end part and when the driving voltage is not supplied to the switching relay, the single switch device operates in the second switching state. The retrofit tubular lamp according to claim 7.

9. The switching relay has a contact part movable between a first position and a second position. In the first position, the contact part connects the input terminal to the first output terminal, and in the second position, the contact part connects the input terminal to the second output terminal. The driving part is configured to control the position of the contact part, is coupled between the first end part and the second end part of the input interface, and the driving part extracts sufficient power to generate the driving voltage to control the position of the contact part when there is no external impedance connected to the input interface, and is configured such that when there is an external impedance connected to the input interface, it cannot extract sufficient power to generate the driving voltage to control the position of the contact part. The retrofit tubular lamp according to claim 7.

10. The retrofit tubular lamp according to claim 9, wherein the driving part has a coil configured to control the position of the contact part and a safety capacitor device connected in series with the coil.

11. The single switch device has a switch input terminal connected to the output of the rectifying device, a first switch output terminal directly connected to the light emitting device, a second switch output terminal directly connected to the converter, and a switching part connected to the switch input terminal and controllable manually at least between a first switching part position, a second switching part position, and a third switching part position, and has a dip switch or a relay. In the first switching part position, the switching part connects the switch input terminal to the first switch output terminal, thereby operating the single switch device in the first switching state. In the second switching part position, the switching part connects the switch input terminal to the second switch output terminal, thereby operating the single switch device in the second switching state. In the third switching part position, the switching part is disconnected from both the first switch output terminal and the second switch output terminal. The retrofit tubular lamp according to claim 3.

12. The creepage distance between the switching part and the first switch output terminal when the switching part is in the position of the third switching part is greater than a predetermined threshold value, optionally greater than 1.5 mm. The retrofit tubular lamp according to claim 11.

13. The retrofit tubular lamp according to claim 1, wherein the single switch device is in the second switching state by default when the retrofit tubular lamp is not powered.

14. The light emitting device is a plurality of light emitting units, and a reconfiguration circuit, when the single switch device is operating in the first switching state, the light emitting units are configured to be connected in series, and when the single switch device is operating in the second switching state, the light emitting units are configured to be connected in parallel. The retrofit tubular lamp according to claim 1, comprising a reconfiguration circuit configured as such.

15. The retrofit tubular lamp according to claim 1, further comprising a linear regulator connected between the converter and the light emitting unit for the second type of power supply, and optionally, the linear regulator is disconnected from the first current path between the first end and the second end of the input interface for the first type of power supply.

16. The first type of power supply is a high-frequency power supply / stabilizer configured to power a fluorescent lamp, The second type of power supply is a low-frequency power supply, optionally including a low-frequency stabilizer or a main power supply configured to power a fluorescent lamp. The retrofit tubular lamp according to claim 1.

Images