LIGHTING ARRANGEMENT

TECHNICAL FIELD

The present invention generally relates to an add-on unit which can be retrofitted with e.g. an existing lighting arrangement to control and monitor the operation of the existing lighting arrangement. The invention also relates to a system comprising a plurality of such add-on units and to a lighting arrangement comprising such add-on unit.

BACKGROUND OF THE INVENTION

Lighting devices installed in for example hospitals, malls, offices, schools, and other publicly accessibly places are vast and require frequent monitoring for ensuring reliable operation. This is particularly important for emergency lights which may be installed for e.g. guiding people in a suitable direction in case of an emergency, or for lighting up signs which indicate the direction of evacuation routes or exits. An emergency lighting system typically includes battery capacity, a lamp, a transfer switch between the battery and the mains, and a charger for the battery. The operation of emergency lighting systems has to be tested frequently. One way to monitor such lighting devices is by manual inspection, either through maintenance personnel inspecting on-site of the lighting device or e.g. via surveillance cameras. However, this is a time consuming and costly inspection method. Furthermore, testing of the lighting systems may require a simulated loss in main building power.

An exemplary implementation for trying to overcome this problem is disclosed in US2014/0320011. US2014/0320011 provides emergency lighting fixtures that use light-emitting diodes (LEDs) having operating life time superior to conventional incandescent or fluorescent lamps. Furthermore, in order to additionally increase operation durability and reduce the required battery power during an emergency, special electronic circuits have been designed, as well as specialized optics. This way, the amount of maintenances is reduced. In addition, a central battery system is provided in

US2014/0320011 which provides backup power and diagnostics of the system which may report back to a user.

Even though US2014/0320011 introduces a possible approach for emergency lighting systems, there appears to be room for further improvement in regards to existing lighting systems in need of upgrading to enable e.g. monitoring of the operation of the lighting system. For example, in most public places there is already lighting systems installed which are intended to be used during normal operation conditions and emergency situations, e.g. as emergency lighting. Such systems would benefit from a cost efficient and straight forward modification to allow e.g. monitoring of lighting operation of the systems. Thus, it is desired to avoid replacing the already installed lighting systems. SUMMARY OF THE INVENTION

In view of above-mentioned and other drawbacks of the prior art, it is an object of the present invention to provide an add-on unit for monitoring and controlling the operation of an already existing lighting arrangement. The add-on unit may be retrofitted with the existing lighting system.

According to an aspect of the present invention, it is therefore provided an addon unit for monitoring and controlling the operation of an existing lighting arrangement, the lighting arrangement comprising a light source, an input connection port for connecting the light source to the mains, and a backup power source, the backup power source being adapted as a backup for powering the light source in case of failure of supply of power from the mains to the light source, the add-on unit being adapted to be retrofit with the existing lighting arrangement, wherein the add-on unit comprises sensing means adapted to determine the light intensity emitted from the existing lighting arrangement, an input port for connecting the add-on unit to the mains, a power line communication circuitry connected to the input port, a power output port connectable to the input connection port of the existing lighting arrangement, a switch unit electrically connected to the input port and to the power output port, the switch unit being configured to adjust an amount of electrical power provided to the power output port from the input port, and a control unit controllable via the input port to control the switch unit to adjust the amount of electrical power, the control unit is further configured to, in response to the adjusted amount of electrical power provided to the power output port, receive a signal from the sensing means indicative of the light intensity and to send the signal to the input port to report the light intensity to a user; and a housing for accommodating the input port, the power line communication circuitry, the power output port, the switch unit, and the control unit.

The present invention is based upon the realization that existing lighting arrangement may in a simple way be provided with controlling and monitoring means by an add-on unit which may be retrofit to any existing lighting arrangement.

The term "retrofit" should be interpreted as that the add-on unit may be implemented to the function of any existing lighting arrangement without substantial modification of the existing lighting arrangement. Existing lighting arrangements may for example be of different types or models throughout a building and may also have different types of backup power sources, for example a backup power source in the form of a battery or an uninterruptible power source (UPS) of some kind. The present invention provides a means of controlling and monitoring the existing lighting arrangements in e.g. a hospital, regardless of the backup power source or type of existing lighting arrangement, without replacing the entire existing lighting arrangement. Thus, the add-on unit is a stand-alone unit which may be integrated with the existing lighting arrangement which may already be operational at a site. The amount of electrical power provided to the existing lighting arrangement may be provided from the mains power through the power lines of the building or site where the lighting arrangement is installed. Furthermore, the add-on unit advantageously provides a means of communication between the existing lighting arrangement and a user via the power lines of the e.g. building or site. In addition, the add-on unit provides a functionality of testing the backup power source and thereby the backup lighting functionality of the existing lighting arrangement system.

In accordance to the invention, the sensing means determines the light intensity emitted from the existing lighting arrangement. This includes determining a measure related to the actual light intensity, or to measure the actual light intensity itself, or a relative light intensity relative to e.g. a previously determined light intensity. The existing lighting arrangement comprises a suitable light source such as an LED, fluorescent, incandescent light source, etc.

The input port of the add-on unit enables power from the mains to be connected to the existing lighting arrangement. Thus, the power provided to the existing lighting arrangement runs via the add-on unit when the add-on unit is installed with the existing lighting arrangement. The mains may be the e.g. 230/110 V mains of the site or building of the existing lighting arrangement. The control unit may be controllable via the input port and thereby via the power lines of the building or site. Thus, a power line communication protocol may be used to communicate with the add-on unit from a remote location.

The switch unit enables adjustment of the power from the primary power source to the existing lighting arrangement. Such switch units may be e.g. a mechanical relay, an electronic relay (e.g. transistor type relays), a potentiometer, etc.

The adjustment of the electrical power may relate to e.g. an increase or decrease of the electrical power relative to a first level of power, for example the normal operation power from the mains, or from a low power operation in a stand-by mode of the existing lighting arrangement, or from a predetermined threshold level of power.

The control unit may be controllable via the input port by an electrical connection between the control unit and the input port. The electrical connection may be via the power line communication circuitry, thus the control unit may be electrically connected with the power line communication circuitry. The control unit may receive the signal from the sensing means via an electrical connection by means of e.g. a wire, or by wireless communication.

The power line communication circuitry may include electrical components such as AC/DC converters, filters, passive or active electrical components, etc.

In one embodiment of the invention, the switch unit is configured to (completely) break the electrical connection between the power output port and the input port. In other words, the switch unit is configured to break the electrical connection between the existing lighting arrangement and the mains. Thereby, the backup power source of the existing lighting system is activated to provide backup power to the existing lighting system to power the light source. Thus, breaking the electrical connection simulates a loss in main building power which causes the backup power to power the existing lighting system. The sensing means may measure the light intensity emitted from the existing lighting system powered by the backup power so that the control unit may receive a signal indicative of the measured the light intensity in this situation. In this way, according to an embodiment of the invention, the signal from the sensing means provides an indication of the status of the backup power source. For example, if the determined light intensity is determined to be "low", it may be concluded that the status of the backup source is inadequate, or if the determined light intensity is determined to exceed a threshold indicative of proper functioning; the status may be that the backup source is "OK".

According to an embodiment of the invention, the sensing means is a light sensor mountable to measure the light intensity emitted from the lighting arrangement. The light sensor may be mountable on an outer side of the existing lighting arrangement. It is thereby provided an advantageous installation procedure by being able to simply mount the light sensor on the existing lighting arrangement so that the light sensor may measure the light emitted from the existing lighting arrangement. The light sensor may be any suitable type of photodetector or even a video camera. Furthermore, the add-on unit may comprise means for determining the temperature (e.g. thermometer) in the vicinity of the add-on unit or on the add-on unit itself. For example the means for determining the temperature may e.g. determine the temperature of the existing lighting arrangement or the surroundings of the existing lighting arrangement.

In an embodiment of the invention, the sensor means is integrated with the housing and facing outside of the housing. The sensor means may thus be an integral part of the housing, e.g. mounted in a hole or cavity of the housing. Thereby, a more compact add-on unit is provided. This is advantageous for example if the add-on unit may be placed close the existing lighting arrangement.

According to an embodiment of the invention, the sensor means is arranged external to the housing and electrically connected with the control unit via a wire extending away from the housing. Thus, the sensor means may relatively freely be positioned with relation to the existing lighting arrangement. For example, the housing may be placed some distance from the existing lighting arrangement due to space or interior design restrictions, and the sensing means may nevertheless be arranged so that it may determine the light intensity or the light emitted from the existing lighting arrangement.

According to an embodiment of the invention, the control unit is remotely controllable from a central control unit via the input port. This provides remote access to the add-on unit and thereby to monitor and control the existing lighting systems from a remote location. For example, testing of the backup power source may be done without the need for maintenance personnel to be at the site of the existing lighting system. The control unit may be in communication with the central control unit via a power line communication protocol, the power lines being the power lines of the building or site where the add-on unit is installed.

The power line communication circuitry and the control unit are advantageously a single component.

The existing lighting arrangement may for example be an emergency exit sign comprising a light source.

According to an aspect of the invention, there is further provided a lighting arrangement comprising the add-on unit according to any one of the above-mentioned embodiments provided as an integrated component of the lighting arrangement.

According to another aspect of the present invention, there is provided a system comprising a plurality of add-on units according to the preceding embodiments, the system further comprises a central control unit configured to be in communication with the plurality of add-on units via the mains power lines. According to an embodiment of the invention, the central control unit is configured to control the control unit of each of the add-on units, wherein the signal indicative of the light intensity determined by the respective sensing means is receivable by the central control unit.

According to an embodiment of the invention, the central control unit is configured to communicate with the add-on units using a power line communication protocol.

This aspect of the invention provides similar advantages as discussed above in relation to the previous aspects of the invention.

Within the context of the invention, the expression "control unit" should be understood to include any type of computing device, such as an ASIC, a micro-processor, etc. It should also be understood that the actual implementation of such a processing circuitry may be divided between a plurality of devices/circuits.

It should be understood that the expression terminal may be used interchangeably with the expression port throughout the description, symbolizing a connection point for receiving/providing mains (e.g. 230 VAC).

Advantages of the invention includes the possibility of testing the status of the backup power source without the need to break the main power to other electrical devices connected to the same mains, for example other lighting arrangements in the building.

Furthermore, testing of the existing lighting arrangement may be performed without the need for maintenance personnel to be at the site of the existing lighting system. In addition, monitoring of the overall operation and testing of the existing lighting arrangement may be performed remotely. In particular, the present invention advantageously provides a means of controlling and monitoring the existing lighting arrangements regardless of the backup power source or type of existing lighting arrangement, without replacing the entire existing lighting arrangement.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled addressee realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

Figs, la schematically exemplify an add-on unit according to the present invention arranged with an existing lighting arrangement in the form of an emergency exit sign;

Fig. lb schematically shows the add-on unit shown in Fig. la; and Fig. 2 conceptually illustrates a system comprising a plurality of add-on units according to an embodiment of the invention.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person. Like reference characters refer to like elements throughout.

Turning now to the drawings and to Fig la in particular, there is schematically illustrated an add-on unit 100 according to the present invention which has been retrofitted with an existing lighting arrangement 101 in the form of an emergency exit sign 101 having a light source 103 and a backup power source 108, for example in the form of a battery. The backup power source 108 may be integrated with the existing lighting arrangement 101 or may be arranged external from the existing lighting arrangement 101 without compromising the functionality of the add-on unit 100. In the shown example embodiment, the add-on unit 100 is retrofitted with the existing lighting arrangement 101 by electrically connecting an input port 114 of the add-on unit 100 with the mains 106. A power output port 118 of the add-on unit is electrically connected with an input connection port 105 of the existing lighting arrangement 101. The input connection port 105 may be the otherwise used power input port 105 for connecting the light source 103 of the existing lighting arrangement 101 to the mains power 106. Thus, the add-on unit 100 is electrically arranged between the main 106 and the power input port 105 of the existing lighting arrangement 101. A sensing means 110 in the form of a light sensor 110 is arranged to determine the lighting intensity of the light emitted by the light source 103 of the existing lighting arrangement 101. In this example embodiment, the light sensor 110 is mounted on an outer side 124 of the existing lighting arrangement 101. The light sensor 110 is further electrically connected to the add-on unit 100 via a wire 126. The wire 126 may be replaced by wireless communication.

With reference to Fig. lb, there is conceptually illustrated an add-on unit 100 according to an embodiment of the invention. The add-on unit 100 comprises a sensing means 110, a housing 112 (here represented by the dashed line, see also Fig. la), a power line communication circuitry 116, an input port 114, a power output port 118, a switch unit 120, and a control unit 122. The sensing means 110 which may be in the form of a light sensor is electrically connected with the control unit 122 via a wire 126. The sensing means 110 is adapted to measure a light intensity (described with reference to Fig. la) so that the control unit 122 can receive a signal via the wire 126 from the sensing means indicative of the determined light intensity. The wire 126 may be provided through a hole (not shown) of the housing 112 and may extend away from the housing 112 to allow the sensing means 110 to placed some distance from the housing 112. The input port 114 and the power output port 118 may be mounted in a hole or cavity (not shown) in the housing 112, thus to provide convenient connection joints. The input port 114 may be connected to the mains 106 via e.g. a cable 128 or the input port 114 may be directly plugged in to the mains via a power plug. Similarly, the power output port 118 is adapted to be electrically connected to the input connection port 105 of the existing lighting arrangement 101 via e.g. a cable 130, the mains 106 being the typical 230/110 VAC and the cables 128, 130 suitable for carrying such voltages and the corresponding powers.

Furthermore, a switch unit 120 is arranged in the housing 112 and is electrically connected to the input port 114 and to the power output port 118. Thus, the switch unit 120 is electrically connected between the input port 114 and the power output port 118. The switch unit 120 may adjust the electrical power provided to the power output port 118 from the input port 114. In this particular embodiment, the switch unit is in the form of a relay 120 which may be e.g. a mechanical or electrical relay. The switch unit 120 may for example break the electrical connection between the input port 114 and the power output port 118 so that the mains 106 are disconnected from the existing lighting arrangement 101. In such case, the backup power source 108 of the existing lighting arrangement 101 provides backup power to the existing lighting arrangement 101 so that the light source 103 may still emit light. The sensing means 110 may then measure the light intensity emitted by the light source 103 when powered by the backup power source 108. The measured light intensity is communicated to the control unit 122 which may send a signal indicative of the light intensity to the input port 114 to report the light intensity to a user. The input port 114 may thus serve as a port for a power line communication protocol so that the control unit 122 can communicate with e.g. a central control unit (not shown, see Fig. 2) via the mains power lines 204 of the building or site. In case of breaking the electrical connection between the input port 114 and the power output port 118, the backup power source 108 powers the light source 103, and the signal indicative of the light intensity of the light emitted by the light source 103 is also indicative of the status of the backup power source 108.

There is further shown in Fig. lb a power line communication circuitry 116 connected to the input port 114. The power line communication circuitry 116 may comprise electrical components such as AC/DC converters, filters, passive or active electrical components, etc. for receiving and converting the mains power suitably for processing by the control unit 122. Although depicted as two separate units in Fig. lb, the power line communication circuitry 116 and the control unit 122 may be arranged as a single

component.

Fig. 2 conceptually illustrates a system 200 comprising a plurality of add-on units 100 and a central control unit 202 according to an embodiment of the invention. The central control unit 202 is in communication with the add-on units 100 via the mains power lines 204 through a power line communication protocol (e.g. G3PLC standard). The central control unit 202 may serve as a gateway for the system 200. The central control unit may receive the signal indicative of the determined light intensity from each of the add-on units 100 and may thus perform remote monitoring of the existing lighting arrangements of each add-on unit 100. For example, each of the add-on units 100 may be arranged to monitor and control the operation of a respective existing lighting arrangement located in different rooms or locations of a building. In Fig. 2, the add-on units are connected in parallel with each other. However, more than one (e.g. two, or three, or four, or five, or six, etc) add-on unit 100 may be connected in series which is often the case.

The control unit 122 may each include a microprocessor, microcontroller, programmable digital signal processor or another programmable device. The control unit 122 may also, or instead, each include an application specific integrated circuit, a programmable gate array or programmable array logic, a programmable logic device, or a digital signal processor. Where the control unit 122 includes a programmable device such as the microprocessor, microcontroller or programmable digital signal processor mentioned above, the processor may further include computer executable code that controls operation of the programmable device.

The control functionality of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwire system. Embodiments within the scope of the present disclosure include program products comprising machine- readable medium for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. When information is transferred or provided over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless) to a machine, the machine properly views the connection as a machine-readable medium. Thus, any such connection is properly termed a machine-readable medium.

Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Additionally, even though the invention has been described with reference to specific exemplifying embodiments thereof, many different alterations, modifications and the like will become apparent for those skilled in the art.

In addition, variations to the disclosed embodiments can be understood and effected by the skilled addressee in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. Furthermore, in the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.