Patent Publication Number: US-2023138074-A1

Title: Device and method for controlling a lighting and sanitizing system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This patent application claims priority from Italian Patent Application no. 102021000028142 filed on Nov. 4, 2021, the entire disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a device and method for controlling a lighting system which integrates lighting and sanitizing (disinfectant, antibacterial, etc.) functions. 
     BACKGROUND 
     The use of UV lamps (in particular, UV lamps emitting in the UV-C band) with sanitizing function is well known, UV light being capable of deactivating or eliminating pathogenic microorganisms. 
     On the other hand, UV-C light is not suitable for lighting environments and also has potentially dangerous effects on humans too, if not properly controlled. 
     It is also known that certain light radiations in the visible range, particularly in the violet range, can have disinfectant effects. Lighting devices are therefore known which include a light source emitting specific-wavelength violet light with disinfectant function combined with a light source emitting a complementary light resulting in white light. 
     In general, well-known lighting devices that are also equipped with UV-C sources and/or violet light sources with sanitizing function are not fully satisfactory. 
     In particular, the problem arises of a safe control of potentially hazardous emissions for users. In fact, not only UV radiation, but also violet light having a wavelength suitable for the sanitizing function can be harmful, especially if users are exposed for long periods and/or at high intensity. 
     SUMMARY 
     The object of the present invention is to overcome the drawbacks of the prior art, in particular by providing a device and a method for controlling a lighting and sanitizing system which is simple and reliable and fully efficient and safe. 
     The present invention therefore relates to a device and a method for controlling a lighting and sanitizing system as defined in appended claims  1  and  10 , respectively. 
     The invention provides a device and method for controlling a lighting and sanitizing system, which is simple and reliable, and fully efficient and safe. In particular, the control device and method of the invention ensure that the sanitizing source, potentially dangerous to users, is only activated under full safety conditions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features and advantages of the present invention will be apparent from the description of the following non-limiting embodiment with reference to the figures of the accompanying drawings, wherein: 
         FIG.  1    is a schematic view of a lighting and sanitizing system equipped with a control device according to the invention; 
         FIG.  2    is a schematic view of the control device of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The numeral  1  in  FIG.  1    shows, as a whole, a lighting system with lighting and sanitizing functions, for example, operating in an environment (one or more rooms). 
     The lighting system  1  comprises at least one lamp  2  including at least one sanitizing source  3 , which emits radiation capable of performing a sanitizing function, such as for example UV radiation, in particular UV-C, or violet light having a wavelength between 380 and 430 nm. 
     The lamp  2  may include one or more sanitizing sources  3 , even different ones (e.g., one or more UV sources and one or more violet light sources); optionally, the lamp  2  may also include one or more visible light sources  4  emitting white light, alone and/or in combination with respective violet light sources. 
     The lighting system  1  may comprise a plurality of lamps  2 , even different ones, i.e., equipped with different sanitizing sources  3  and/or different visible light sources  4 . 
     For example (but not necessarily), the lighting system  1  comprises one or more lamps of the type described in Italian Patent Application no. 102020000010399. 
     For the sake of simplicity, reference will be made hereinafter to a lighting system  1  with a single lamp  2  equipped with one sanitizing source  3 , but it is understood that the invention can also be implemented with several lamps  2  and/or several sanitizing sources  3 . 
     The lighting system  1  comprises a control device  5  connected to the lamp  2  and controlling the lamp  2 , and in particular the sanitizing source  3 , in order to avoid health risks to users who may be exposed to the emission from the sanitizing source  3 . 
     Also referring to  FIG.  2   , the control device  5  comprises, in particular, a printed circuit board  10 , comprising: 
     a supply input  11  for connection to a power supply, for example a 12-48 V direct current power supply; 
     a sensor input  12  connected to a presence sensor  13 , for example a PIR sensor (passive infrared sensor); 
     an outer sensor input  14  for connection to further outer sensors  15 , e.g., one or more further presence sensors and/or door opening sensors and/or a consent sensor (which can be activated, for example, by means of a key or an unlock code); 
     a first relay contact output  16  for connection to a visual signalling LED  17 ; 
     a second relay contact output  18  for connection to a sound signal  19  (a buzzer); 
     a third relay contact output  20  for sanitization in progress; 
     a fourth relay contact output  22  for connection in series to a driver  23  of the sanitizing source  3 ; 
     a current measure input  24  for measuring the current in the sanitizing source  3 ; 
     a transformer input  25  for connection to an amperometric transformer  26  for measuring the primary current in the driver  23  of the sanitizing source  3 . 
     The supply input  11  comprises, for example, a pair of supply terminals  11   a ,  11   b  connected to a power supply  27 . 
     The sensor input  12  comprises three terminals  12   a ,  12   b ,  12   c , including an earth terminal  12   a , which are connected to the presence sensor  13 . The presence sensor  13  is placed in the room where the lighting system  1  is located to detect the presence of people in this room. 
     The outer sensor input  14  comprises a pair of terminals  14   a ,  14   b  connected to the sensors  15 , in particular one or more door opening sensors acting on respective doors of the room in which the lighting system  1  operates, to detect the opening of these doors. 
     The first output  16  is the output of a first relay  31 , in particular a low voltage (max 50V, 100 mA) static relay, and comprises a pair of terminals  16   a ,  16   b  connected to the visual signalling LED  17 , which is placed in an appropriate position to send a visual signal (steady or flashing light) to users. 
     The second output  18  is the output of a second relay  32 , in particular a low voltage (max 50V, 100 mA) static relay, and comprises a pair of terminals  18   a ,  18   b  connected to the sound signal  19 , which is placed in an appropriate position to send a sound signal to users. 
     The third output  20  is the output of a third relay  33  to signal sanitization in progress (e.g., max 250V, 3 A), and comprises a pair of terminals  20   a ,  20   b  to indicate that the sanitizing source  3  is switched on and sanitization is in progress. 
     The fourth output  22  is the output of a fourth relay  34  (e.g., max 250V, 3 A) connected in series to the driver  23  of the sanitizing source  3  and comprises a pair of terminals  20   a ,  20   b.    
     The current measure input  24  comprises a pair of terminals  24   a ,  24   b  connected to the sanitizing source  3  to measure, via an amperometric sensor  35 , the current to the lamp load (secondary driver), i.e., the current in the sanitizing source  3  on the secondary side of the respective driver  23 . 
     The transformer input  25  comprises a terminal  25   a  connected to the transformer  26  for measuring the primary current in the driver  23  of the sanitizing source  3 . The other wire of the transformer  26  is inserted in the earth terminal  12   a.    
     The control device  5  is then provided with a communication system  37 , preferably a wireless communication system, for example Bluetooth, to communicate, other than with the presence sensor  13  and the other sensors  15 , with a remote device  38 , for example, a smartphone or other similar device loaded with a dedicated application (app) providing a user interface with the control device  5 . 
     The operation of the control device  5  and thus of the lighting system  1 , for implementing the method according to the invention, is as follows. 
     Via the app (and therefore via the device  38 ) the user can select various functions, in particular:
         safety chain operation test: the app activates a command setting the control device  5  into test mode. In this mode, if the presence sensor  13  and/or one of the other sensors  15  (e.g., a door opening sensor) detects a presence or the opening of a door:       

     1) the first output  16  is activated and the visual signalling LED  17  switches on; in this way, a visual test is carried out for the correct functioning of the safety chain, which activates instantaneously if users are present; and 
     2) the second output  18  is activated and the sound signal  19  switches on; in this way, a sound test is carried out for the correct functioning of the safety chain, which activates instantaneously if users are present;
         activation of sanitization: either via the app or via a switch  39  (e.g., a b11-type switch), the sanitizing source  3  (or the entire lamp  2 ) is switched on; the control device  5  provides the consent to switch on the sanitizing source  3 .       

     In particular, the app (via the device  38 ) or the switch  39  sends a command to the control device  5 ; after a preset exit time (which can be set through the app to allow exit from the room), the control device  5  sends an indirect command to the sanitizing source  3 . The third relay  33  closes to indicate that sanitization is on. 
     During the exit time, the first relay  31  (for the visual signalling LED  17 ) and the second relay  32  (for the sound signal  19 ) are active, e.g., intermittently. Optionally, however, the output of the sound signal  19  can be silenced via the app. 
     When the exit time is over, the second relay  32  (the sound signal  19 ) switches off and the first relay  31  (the visual signalling LED  17 ) flashes to indicate that sanitization is in progress.
         Disabling of sanitization: the sanitizing source  3  is disabled via the app (the device  38 ) or the switch  39 , or by intervention of the presence sensor  13  or of one of the other sensors  15 .       

     Once the corresponding signal has been received, the control device  5  opens the third relay  33  and the first relay  31  to indicate that the sanitization is switched off. 
     This step measures the value of the current in the load (the sanitizing source  3 ) by means of the amperometric sensor  35 : 
     1) if the measured current is lower than a threshold value preset in the control device  5 , this means that the sanitizing source  3  (e.g., the violet light source) is switched on in a non-hazardous manner, or is switched off; 
     2) if the measured current is higher than the preset threshold value (the sanitizing source  3  is activated above the threshold value), the control device  5  sends a command for reducing or switching off the power of the sanitizing source  3  to the respective driver  23 . The sanitizing source  3 , following this command, goes back to the pre-sanitization state (for example, a state where the sanitizing source  3  is switched off or operates below the threshold value). If the measured current still does not fall below the threshold value (which is a safe value for the exposure of users), the fourth relay  34  intervenes by cutting off the power to the driver  23  of the sanitizing source  3 . 
     The presence sensor  13  and the other sensors  15  define a safety chain, and the control device  5  is configured to give consent to the use of the sanitizing source  3  only if the safety chain is closed, that is, if all safety criteria are met. 
     If, then, during operation in the sanitizing mode (sanitizing source  3  on), the control device  5  detects an interruption of the safety chain, e.g., the presence of a person detected by the presence sensor  13  or the opening of a door detected by one of the sensors  15 , the control device  5  stops the sanitization by switching off the sanitizing source (or reducing its power supply below the safety threshold value). 
     In the event of a malfunction of the wireless communication system (or, in any case, of the communication system, which can also be wired, between the control device  5  and the presence sensor  13  and the other sensors  15 ), the control device  5  is still able to ensure user safety, because the amperometric sensor  35  monitors the current flowing in the sanitizing source  3 , and if the source is switched on and a malfunction is detected in the communication system, it disables the sanitizing source  3 . 
     Additional safety features are the alerts sent during sanitization by the visual signalling LED  17  and the sound signal  19 . 
     The following settings are available through the app:
         activation of the safety chain operation test;   on/off setting of the sound signal;   self-calibration of the current threshold value in the sanitizing source;   setting of the exit time prior to the switching on of the sanitizing source;   setting of the automatic sanitization switching off time.       

     The control device  5  allows a shared line to be used safely for all operating modes: in fact, the control device  5  discerns the operating mode actually in progress on the basis of the absorption detected by the amperometric sensor  5 : if the amperometric sensor  35  detects a current higher than the threshold value, the lighting system  1  operates in the sanitizing mode (for example, night mode); if it detects a current lower than the threshold value, the lighting system  1  operates in the daytime mode (without sanitization). In the event of an interruption of the safety chain, as described above, the control device  5  intervenes and switches off the sanitizing source or reduces its power supply below the safety threshold value. 
     Lastly, it is understood that the control device and method as described and illustrated herein can be subject to modifications and variations that do not depart from the scope of the accompanying claims.