An improved LED dimmer

Abstract

A lighting dimmer control unit 10 with an oblong casing 12 and at least one surface indent 20. Multiple indents 20 may be provided opposite to one another on two side faces of the casing 12. The light

Description

Field of the invention The present disclosure relates to an improved dimmer for controlling light emitting diode (LED) lights. Background to the invention As LED lighting has become mainstream in recent years, the technology of controlling LED lighting has been developed alongside. Especially, the technology relating to the control of dimming of LED lighting has developed. Legacy lighting systems, such as incandescent and halogen bulbs, were relatively straightforward to control the dimming of. Typically, where legacy lighting systems were powered by AC current, dimming has been performed by leading edge dimming via a relatively straightforward transistor circuit. Leading edge dimming is where the leading edge of an AC current cycle is curtailed to reduce the overall power transmission to a bulb or the like. Due to the way LED lights function, which is clearly different from legacy lighting as described, many LED lights perform better with trailing edge dimming. Trailing edge dimming is where the trailing edge of an AC current cycle is curtailed. The overall power output provided by each type of dimming can be similar, but trailing edge dimming can provide for a more pleasing optical appearance and longer life of the lighting unit. Existing dimmers already installed-for example in domestic or commercial settings -may be replaced to improve the performance of connected LED lighting. Examples may include existing wall-mounted dimmers. Alternatively, existing binary switches already installed may be replaced to improve functionality. Summary of invention A first aspect of the present disclosure provides a lighting dimmer control unit, having a housing comprising a generally oblong casing portion having a front face, a back face and two side faces, wherein the casing portion comprises at least one indent formed in the surface thereof. An indent is designed to provide an overall form factor which aids the fitting of the lighting dimmer control unit in an electrical back box. A key object of the present disclosure is to provide a lighting dimmer control unit which can fit within a wide range of back boxes - whether traditional back boxes or contemporary arrangements which might, for example, include grid adaptors. An indent may be formed on any face of the casing portion. An indent is preferably shaped and located to avoid another component which may be present. Such potential components may be, for example, lugs, support elements, support vanes, grid adaptor components or the like which might be located within a back box. A back box or other space into which a lighting dimmer control unit might be located can be understood as being cramped and somewhat uncertain because of the number of possible components that might also be needed to be present. Thus, by providing one or more indents of suitable shape and location, a lighting dimmer control unit can be fitted into a wide range of potential settings. An indent may be formed on one of the two side faces of the casing portion. An indent may be formed on each of the two side faces of the casing portion. Two indents formed on the two side faces of the casing portion may be located approximately opposite one another. This arrangement provides for improved fitting of a lighting dimmer control unit to an existing lighting fitting such as a back box or other space. It also provides for improved compatibility and versatility - in that the control unit can be fitted into a wide range of possible spaces where perhaps a lighting dimmer control unit could not be fitted previously. For example only, it might be possible to fit more lighting dimmer control units as described safely into a back box than previously would have fitted due to the constraints of said back box. Thus the present disclosure provides for more possibilities and versatility. One or more indents may have an arc-shaped cross-section. This shape might also be described as a half-moon shape. The radius of an arc of such an arc-shaped cross section may be approximately 5 to 15 mm. One or more indents may extend substantially from the front face to the back face in the respective side of the housing. Alternatively or in addition, an indent may form a step in the casing portion. The lighting dimmer control unit may further comprise a dimmer rod extending from the front face of the housing. The housing may further comprise electrical connections with openings on the back face of the housing. The lighting dimmer control unit may be adapted to provide for a rotational movement around an axis of said dimmer rod. The rotational movement may be limited to provide a maximum clockwise rotation and a maximum anti-clockwise rotation. For ease of labelling, the maximum clockwise rotation position will be referred to as a "max" setting and the maximum anti-clockwise rotation will be referred to as a "min" setting. The lighting dimmer control unit may be adapted to provide for an axial movement of said dimmer rod. Thus, the dimmer rod may be pressed axially into the housing. The lighting dimmer control unit may further comprise a sprung actuator adapted to return said dimmer rod to an axial starting position after having been pressed axially into the housing and then released. In use, a user may press in the dimmer rod and release it to switch on or off the dimmer control unit. In other words, if the dimmer control unit is off and the user presses and releases the dimmer rod, the dimmer control unit will be switched on; if the dimmer control unit is on and the user presses and releases the dimmer rod then the dimmer control unit will be switched off. The user may rotate the dimmer rod around its axis between the max and min settings. The lighting dimmer control unit may further com prise a press button on the back face of the housing. The lighting dimmer control unit may further comprise a self-resettable thermal fuse. The lighting dimmer control unit may further comprise a short-circuit cut-out. A second aspect of the present disclosure provides a lighting dimmer control unit, wherein the lighting dimmer control unit comprises a programmable control circuit connected to electrical connections and a dimmer rod, and adapted to provide an alternating current power output to at least one of the electrical connections. The lighting dimmer control unit may be adapted to switch on or off the alternating current power output to at least one of the electrical connections by pressing the dimmer rod. The control circuit may be further adapted to modify the waveform shape of the alternating current output provided to at least one of the electrical connections. The programmable control circuit may be pre-programmed with waveform settings suitable for a selection of light emitting diode (LED) types. Different types of LEDs have different performance characteristics with different shapes of waveform of alternating current. Thus, with a programmable control circuit programmed accordingly, the lighting dimmer control unit can be adapted for use with many different LEDs. The programmable control circuit may comprise a database of waveform settings stored within a ROM, RAM, or re-programmable ROM such as an EPROM, EEPROM or EAROM. When new types of LEDs become available, the database may be updated either on manufacture or via updating in situ. Effecting appropriate waveform settings for a particular type of LED can provide for shorter startup time, greater energy efficiency, improve the operational lifetime of the LED, reduce heat losses. Suitable waveform settings may also include leading edge and trailing edge waveform shapes. Suitable waveform settings may also include maximum and minimum brightness settings. Brightness settings ultimately relate to the overall power output as determined by the degree of waveform curtailment as described above. Thus the suitable waveform settings may include maximum and minimum curtailment settings. The programmable control circuit may be pre-programmed with a non-zero minimum brightness setting - i.e. a minimum power output when the dimmer rod is at a min setting. In other words, if the lighting dimmer control unit is switched on and the dimmer rod is in at the min setting the power output is not zero. This means that a user has visual confirmation that the lighting dimmer control unit is switched on if an LED is connected to the unit. The programmable control circuit may be further adapted to be connected to the press button. The programmable control circuit may be further adapted to receive an electrical signal from the press button to actuate a setup mode. The electrical signal from the press button may comprise a series of press signals received within a pre-determined time period. A series of press signals may comprise, for example, a sequence of presses having a number of presses received over a certain time period. The number of presses and time period can be tracked by the programmable control circuit, and can act as an identification to provide an instruction to the programmable control circuit to enter a desired setup mode. Some examples of potential setup modes and their actuation will now be described. On receipt of three press signals within two seconds, a setup mode may be entered wherein the position of the dimmer rod is recorded to set a minimum brightness setting. On receipt of five press signals within three seconds, a setup mode may be entered wherein the position of the dimmer rod is recorded to set a maximum brightness setting. On receipt of seven press signals within five seconds, a setup mode may be entered wherein the minimum brightness setting and the maximum brightness setting are set back to pre-programmed settings. On receipt of nine press signals within five seconds, a setup mode may be entered wherein the waveform setting switches between leading edge or trailing edge waveform shapes. In other words, on receipt of nine press signals within five seconds, the waveform setting switches between leading edge to trailing edge or vice versa. Other sequences of press signals and time periods can be envisaged which will have a substantially similar technical effect. The programmable control circuit may be pre-programmed with a startup mode and an operational mode, wherein during startup mode one set of waveform settings are used and during operational mode another set of waveform settings are used. A startup mode can reduce start up time for LEDs, improve energy efficiency and operational lifetime of an LED. A startup mode may include a ramp-up mode during which over time the waveform shape varies to increase overall power output from a starting level to a level as set by the dimmer rod. A startup mode may be entered by switching the lighting dimmer control unit on. In other words, the startup mode may be entered by a user pressing the dimmer rod when the lighting dimmer control unit is switched off. The skilled reader will appreciate that the first and second aspects are complementary and can be implemented together. Detailed description of the invention An exemplary embodiment of the present disclosure will now be described in detail, in which: Figure 1 shows a rear elevation of an exemplary lighting dimmer control unit; Figure 2 shows a front elevation of the same lighting dimmer control unit; Figure 3 shows a side elevation of the same lighting dimmer control unit; and Figure 4 shows a perspective view of the rear of the same lighting dimmer control unit showing a user engaging with it. Turning to Figure 1, the exemplary lighting dimmer control unit 10 has a housing having a generally oblong casing portion 12, having a front face (not shown in Figure 1), a back face 16, and two side faces 18. In each of the two side faces 18 is formed an indent 20 which in this embodiment has an arc-shaped cross-section, and the indents 20 extend from the front face to the back face 16 in the respective sides of the housing. Openings 22 of electrical connections are provided on the back face 16 of the casing portion 12. A press button 24 is provided on the back face 16 of the casing portion 12. In Figure 2, the same exemplary lighting dimmer control unit 10 can be seen with a front face 14. Again, the indents 20 can be seen in each of the two side faces 18. Extending from the front face 14 is a dimmer rod 26. The front face 14 also has a step indent 21 formed within it. In Figure 3, the same exemplary lighting dimmer control unit 10 can be seen with a front face 14 and a back face 16 and one of two side faces 18. In the side face 18 shown, an indent 20 is formed as described above. The step indent 21 is also shown, formed in the front face 14. One of the openings 22 of electrical connections can also be seen in Figure 3. A press button 24 is provided on the back face 16. Extending from the front 14 is a dimmer rod 26. In Figure 4, the same exemplary lighting dimmer control unit 10 can be seen in perspective with back face 16 of the casing portion 12 prominent, and having the features as described above and similarly labelled in Figure 4. In Figure 4, the press button 24 is being pressed by a user U. The skilled reader will also appreciate that there are other aspects of the form of the casing which can also be described as indents, which are not specifically labelled or referred to, but which can contribute to the overall form factor of the lighting dimmer control unit.

Claims

1. A lighting dimmer control unit, having a housing comprising a generally oblong casing portion having a front face, a back face and two side faces, wherein the casing portion comprises at least one indent formed in the surface thereof.

2. A lighting dimmer control unit according to claim 1, wherein indents are formed on each of the two side faces of the casing portion approximately opposite one another.

3. A lighting dimmer control unit according to claim 1 or claim 2, wherein one or more indents may have an arc-shaped cross-section.

4. A lighting dimmer control unit, wherein the lighting dimmer control unit comprises a programmable control circuit connected to electrical connections and a dimmer rod, and adapted to provide an alternating current power output to at least one of the electrical connections.

5. A lighting dimmer control unit according to claim 4, wherein the control circuit is further adapted to modify the waveform shape of the alternating current output provided to at least one of the electrical connections.

6. A lighting dimmer control unit according to claim 5, wherein the programmable control circuit is pre-programmed with a non-zero minimum brightness setting.

7. A lighting dimmer control unit, having a housing comprising a generally oblong casing portion having a front face, a back face and two side faces, wherein the casing portion comprises at least one indent formed in the surface thereof, the lighting dimmer control unit further comprising a programmable control circuit connected to electrical connections and a dimmer rod, and adapted to provide an alternating current power output to at least one of the electrical connections.

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