FI127140B

FI127140B - Ballast for light source and combination of ballast and sensor

Info

Publication number: FI127140B
Application number: FI20155442A
Authority: FI
Inventors: Henri Juslén
Original assignee: Helvar Oy Ab
Priority date: 2015-06-10
Filing date: 2015-06-10
Publication date: 2017-12-15
Also published as: FI20155442A

Description

DRIVER FOR A LIGHT SOURCE, AND A COMBINATION OF A DRIVER AND A SENSOR

FIELD OF THE INVENTION

The invention concerns the field of equipping a driver of a light source with a sensor to control its operation. Especially the invention concerns a structure with which the driver can be equipped with either an internal or an external sensor.

BACKGROUND A driver device of light-emitting means is typically built by assembling discrete components and integrated circuits onto a circuit board and enclosing the assembled entity in a metal or plastic casing. Safety regulations and standards may place some requirements to the structure, material, and/or outline of the casing: for example components and conductive tracks with dangerously high voltages must not be directly accessible. Connectors for external wires are among the discrete components on the circuit board, and they (or at least access to them) remain visible and accessible also from outside the casing in the completed product.

One or more of the connectors may be designated for coupling an external sensor, such as a PIR (passive infrared) sensor for presence detection or a light detector for daylight harvesting, to the driver device. Conventionally it has been thought that the sensor is an independent component that is installed somewhere else in the luminaire or even as a standalone device outside the luminaire and wired to the driver device. Another approach is to solder the sensor onto the same circuit board with the other components of the driver device and to make a hole in the casing for the sensor to see through.

Luminaire manufacturers want the functional components to place as few requirements as possible to their freedom to design the structure and appearance of the luminaire. For this purpose it would be advantageous if functional components like the driver device and the possible sensor would allow different approaches to their installation. At the same time the manufacturers of driver devices and sensors would like to keep the number of different models and structural solutions as small as possible, in order not to make the manufacturing logistics too complicated.

SUMMARY

It is an objective of the present invention to provide a structural solution that allows the manufacturer of a luminaire or lighting system to place driver devices and sensors flexibly, while simultaneously allowing the manufacturers of driver devices and sensors to optimize their part of the production process.

The objectives of the invention are reached with a driver device, and with a system comprising a driver device and a sensor, as defined by the respective independent claims.

According to an example embodiment, there is provided a driver device for light-emitting means, comprising: a circuit board, with a controllable power source for said light-emitting means built on said circuit board, a connector on said circuit board for making a coupling between a wire, cable, or optical fiber of a sensor device and said circuit board, a housing encapsulating at least a major portion of said circuit board, a holder for such a sensor device separate from said circuit board for the wire, cable, or optical fiber of which said connector is, and being characterized in that said connector is accessible from outside said housing and said holder is inside said housing.

According to another example embodiment, there is provided a system comprising a driver device for light-emitting means and a sensor, the system comprising a driver device as described above and a sensor device, wherein a wire, cable, or optical fiber of the sensor device connects the sensor device to said connector regardless of whether the sensor device is placed in said holder or installed outside the driver device.

The exemplifying embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" and its derivatives are used in this patent application as an open limitation that does not exclude the existence of also unrecited features. The features described hereinafter are mutually freely combinable unless explicitly stated otherwise.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 illustrates components of a system, fig. 2 illustrates a driver device, fig. 3 illustrates a driver device with a strain relief, fig. 4 illustrates a driver device equipped with a sensor device, and fig. 5 illustrates a driver device with a strain relief and a sensor device.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Fig. 1 illustrates schematically a system comprising the functional parts of a driver device and a sensor device. On the left in the drawing is a circuit board 101, with a controllable power source for light-emitting means built on the circuit board. A connector 102 is provided on the circuit board 101 for making couplings between wires, cables, and/or fibers and the circuit board. Some of the nodes in connector 102 may be provided for coupling operating power to the driver device, while others may be provided for coupling controlled current from the driver device to the light-emitting means. The connector 102 may also comprise nodes for wires, cables, and/or fibers that carry control signals. In the example of fig. 1 it is assumed that at least the two lowest nodes in the connector 102 are provided for this purpose, and a sensor device 103 is used as controlling means.

Not all connections to the driver device are necessarily made through one and the same connector. There may be e.g. separate connectors for operating power, current to the light-emitting means, and control. There may even be two or more connectors for any or all of these purposes, as well as connector(s) for further purposes like providing current to a fan, peltier element or other kind of cooling device.

The circuit board, on which the controllable power source is built, is typically enclosed in a housing for protecting it against dust, moisture, and other environmental conditions. The housing serves also to facilitate easy attachment to a luminaire or other structure, and to prevent unauthorized or accidental access to parts that may carry high voltages, become hot during use, or otherwise pose hazards to users. Fig. 2 is a schematic illustration of a driver device, in which a housing 201 encapsulates at least a major portion of the circuit board 101. Some portions of the circuit board 101 and/or the components attached thereto may be visible and/or accessible through openings in the housing. In fig. 2 one opening 202 is shown for accessing the connector 102, and other openings 203 for allowing surrounding air to pass through, thus facilitating convective cooling of the components inside.

Safety regulations may require to use a strain relief in some installations, while for other installations none is required. For this purpose a separately attachable strain relief can be provided, as illustrated in fig. 3. The strain relief 301 shown here is encapsulated in a separate housing 301 and consists of a number of openings 302 for wires, cables, or fibers, as well as screws 303 for clamping the wires, cables, or fibers against corresponding supports (not shown in fig. 3). The housing 301 of the strain relief may have attachment means (not shown in fig. 3) for attaching it to the housing 201 that enclosed the circuit board and/or to the circuit board itself.

Fig. 4 illustrates a driver device equipped with a sensor device. The upper part of fig. 4 is a partial cut-out view, and the lower part of fig. 4 is a top view. A dashed line 401 across the lower part shows the plane of the partial cut-out view. The driver device comprises a circuit board 101. A controllable power source for light-emitting means is built on the circuit board 101. A connector 102 is provided for making a coupling between a wire, cable, or fiber and the circuit board 101. The connector 102 is a connector for external connections, which means that in a complete, assembled driver device it is accessible either directly or at least easily from outside, for connecting a wire, cable, or fiber coming from another device. A housing 201 encapsulates at least a major portion of the circuit board 101. As a difference to the driver device shown earlier in fig. 1 the driver device of fig. 4 comprises a holder 402 for the sensor device 103. It is to be noted that the sensor device 103 is not installed on the circuit board 101 but is separate therefrom. The wire(s), cable(s), or fiber(s) that connect the sensor device 103 to the circuit board 101 go through the connector 102. The holder 402 offers preferably a detachable mechanical attachment so that both at the installation phase of a lighting system and even later it can be decided, whether the sensor 103 is installed together with the driver device or independently of it somewhere else. The same connector 102 is advantageously used in both cases, so the electrical coupling between the sensor 103 and the driver device is the same independent of whether the sensor 103 is mechanically attached to the driver device or whether it is located elsewhere.

In order to simplify and streamline the manufacturing of the parts of the driver device it is advantageous to manufacture the holder 402 as an integral part of the housing 201. For example, if the housing 201 is made of molded plastic, the holder 402 may be a molded detail of the housing. If the housing is made of metal, the holder may comprise a cut-out and bent portion of the metal sheet of which the housing is made. Other implementations are possible. In a very simple case the holder comprised in the driver device is not much more than a threaded hole in the housing and a screw that goes through some part of the sensor device and attaches it to the housing. A threaded peg (or a tongue or wedge, possibly with one or more notches or other mechanical attachment designs along its length) may even constitute a part of the attachment mechanism of the sensor device, in which case a simple hole or slot, possibly with threads, in the driver device is enough to constitute a holder.

As a difference to known solutions where a sensor may be among the components soldered onto the circuit board, the sensor device 103 is not part of the circuit built on the circuit board 101. Basically it would be possible to arrange the holder for the sensor device 103 at least partly rely upon the circuit board, for example so that a screw or peg in the sensor device would go through a hole in the circuit board or so that the distant end of a spring that keeps the sensor device in place rests against the surface of the circuit board. However, even in such a case the attachment to the circuit board would be purely mechanical, and the electrical connection would in all cases go through the connector 102. If the connector is versatile enough, the direction in which the wires, cables, or fibers of the sensor device are attached to it may vary depending on e.g. whether the sensor device is outside or inside the housing of the driver device.

In the example of fig. 4 the holder 402 is inside the housing 201, so that also the sensor device 103 becomes attached inside the housing 201. Such an arrangement involves the advantage that the outer dimensions of the driver device remain the same regardless of whether a sensor device is installed or not. As an alternative the holder - and consequently also the attachment location of the sensor device - could be outside the housing. The advantage of this alternative solution would involve ease of use, because a sensor device can be attached and detached without opening any part of the housing. Intermediate solutions are possible, in which an installed sensor device would be partly inside and partly outside the housing of the driver device.

If the installation location of the sensor device is inside the housing like in fig. 4, the housing should define one or more openings for allowing a sensor device placed in the holder sense conditions outside the housing. In fig. 4 openings 403 and 404 serve this purpose. The partial insert at the top right in fig. 4 shows how at the time of manufacturing the housing, when it is not yet known whether a sensor device will be installed inside it, such openings may be covered with removable lid portions 405 made of the same material as the housing and connected to the surrounding material of the housing by one or more weakened bridge portions 406. The advantage related thereto is that the same housing parts can be used for driver devices with sensors installed inside the housing, for driver devices with sensors installed elsewhere, and even driver devices that will eventually be used without any sensors at all.

Fig. 5 illustrates a driver device equipped with an additional strain relief and a sensor device. The upper part of fig. 5 is a partial cut-out view, and the lower part of fig. 5 is a top view. A dashed line 501 across the lower part shows the plane of the partial cut-out view. The circuit board 101, the controllable power source built thereon, and the connector 102 are similar to those in fig. 4. A housing 502 encapsulates the actual strain relief part, which consists of screws 503 and the corresponding supports 504. A holder 505 is provided as an integral part of the housing 503, which is preferably made of molded plastic, so that the holder 505 can be a molded detail of the housing 503. Also in this case the holder 505 is inside the housing 503, and the housing 503 defines the necessary openings 506 for allowing a sensor device 103 placed in the holder 505 sense conditions outside the housing 503.

In all cases where the holder for a sensor device is provided as a part of a housing, the housing may define a wiring route for a wire, cable, or fiber between the connector and the sensor placed in the holder. The wiring route may be as simple as sufficient open space left between the internal surface of the housing and the components on the circuit board, but it may also comprise particularly formed holes, recesses, holders, and/or channels that guide the wire, cable, or fiber and keep it e.g. at a safe distance from components that may become hot during use or from components from which electromagnetic radiation could be coupled into a nearby wire or cable. A benefit of the invention is that the designer of a lighting system may purchase driver devices and sensor devices of the kind described above, and use a wire, cable, or fiber to connect the sensor device to a connector in the driver device regardless of whether the sensor device is eventually placed in a holder comprised in the driver device or somewhere else, outside the driver device. So at the moment of ordering the parts of the system the designer does not even have to know in detail, how the final installation will look like. Likewise the manufacturers of driver devices and sensor devices do not need to design and manufacture separate product versions for different kinds of installations.

The exemplary embodiments described above do not constitute an exhaustive or limiting description of the scope of protection defined by the appended claims, but variations and modifications are possible. For example, even if the installation and use of only one sensor has been discussed above, there may be two or more sensors coupled to and operating with the same driver device. In such a case the sensors may be all installed similarly (inside the housing, outside the housing, or at a completely different location than the driver device), or they may be installed differently. Also even if the description above has assumed that the light-emitting means are separate from the driver device, embodiments of the invention may also comprise light-emitting means implemented on the same circuit board or at least enclosed and/or supported by the same housing as the driver device.

Claims

A light source ballast comprising: a circuit board (101) and a controllable power supply built on the circuit board (101) for said light sources, a connector (102) on said circuit board (101) for connecting a wire, cable or optical fiber (101) to the detector device ), the housing (201) enclosing at least a majority of said circuit board (101), separate from the circuit board (101), for a detector device (103) having said connector (102) for a wire, cable or optical fiber. ; characterized in that said connector (102) is accessible from the outside of the housing (201) and said holder (402) is located inside said housing (201).

The ballast of claim 1, wherein said holder (402) is an integral part of said housing (201).

The ballast of claim 2, wherein: said housing (201) is made of molded plastic, and said holder (402) is a molded detail of said housing (201).

The ballast according to any one of the preceding claims, wherein said housing (201) defines one or more openings (403, 404) so that a detector device (103) disposed on the holder (402) can detect conditions outside the housing (201).

The connecting device according to claim 4, wherein said one or more openings (403, 404) are covered by removable cover portions (405) made of the same material as said housing (201) and connected to the surrounding material (201) of the housing (201). with a weakened bridge section (406).

The connecting device according to any one of the preceding claims, wherein said housing (201) defines a path for a conductor, cable or optical fiber between said connector (102) and a detecting device (103) disposed in said holder (402).

A system having a ballast and a detector device (103) according to any one of the preceding claims and wherein a wire, cable or optical fiber of the detector device (103) connects the detector device (103) to said connector (102), whether or not the detector device (103) is (402) or mounted outside the ballast.