Patent Publication Number: US-2016227625-A1

Title: Lamp bypass switch

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application No. 62/110,880, filed Feb. 2, 2015, the contents of which are hereby incorporated herein by reference. 
    
    
     FIELD 
     The present application relates generally to lamps and, more specifically, to a switch for bypassing lamp control electronics. 
     BACKGROUND 
     Control for lamps, such as those lamps used in surgical and diagnostic settings, may currently extend well beyond the on/off control of days gone by. Especially when a lamp is comprised of a plurality of dimmable lamp elements, control for a given lamp may involve turning on or off individual ones of the lamp elements and even controlling the amount of light generated at each lamp element. However, the main control boards that facilitate this degree of control are not immune to failure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Reference will now be made, by way of example, to the accompanying drawings which show example implementations; and in which: 
         FIG. 1  illustrates a lamp; 
         FIG. 2  illustrates, in block diagram form, the lamp of  FIG. 1  and a plurality of control elements, one of the control elements including a button, in accordance with aspects of the present application; and 
         FIG. 3  illustrates the button of  FIG. 2  on a swing arm, where the swing arm may be a support arm for the lamp of  FIGS. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the present application relate to a bypass switch for a lamp, such as a surgical or diagnostic lamp. When activated, the bypass switch may act to allow electric power to bypass elements of the circuitry of a main control board so that the electric power is provided to the plurality of lamp elements. 
     According to an aspect of the present disclosure, there is provided a lamp assembly. The lamp assembly includes a plurality of light sources, a source of electrical power, a control board, a fuse board configured to provide, in accordance with control signals received from the control board, the electrical power, received from the source of electrical power, to the light sources and a bypass switch configured to, responsive to activation, transmit an override signal to the fuse board, wherein the fuse board is configured to, responsive to receipt of the override signal, provide the electrical power, received from the source of electrical power, to the light sources without regard to the control signals received from the control board. 
     Other aspects and features of the present disclosure will become apparent to those of ordinary skill in the art upon review of the following description of specific implementations of the disclosure in conjunction with the accompanying figures. 
       FIG. 1  illustrates a lamp  100  having a plurality of lamp element assemblies  102 . Mounted on each lamp element assembly  102  of the plurality of lamp element assemblies  102  is a plurality of lamp elements  104 . The lamp element assemblies  102  may be mounted within a lamp head  106 . 
       FIG. 2  illustrates, in block diagram form, the lamp  100  of  FIG. 1  and a plurality of control elements. The lamp  100  includes a plurality of dimmable light sources  204 . Each of the light sources  204  may be considered to be a component of a lamp element  104  of  FIG. 1 . The light sources  204  are configured to receive electrical power from a fuse board  208 . The fuse board  208  may be communicatively connected to a control board  214 . In particular, the fuse board  208  may provide power to the control board  214  and receive control signals from the control board  214 . 
     The fuse board  208  is configured to receive electrical power from a power source  212 . 
     Associated with, and communicatively connected to, the emergency bypass switch  210  are a button  220  and a light ring  222 . 
       FIG. 3  illustrates the button  220  on a swing arm  304 . The swing arm  304  may be, for example, a support arm for the lamp  100 . The button is surrounded by the light ring  222 . 
     In overview, aspects of the present application relate to the bypass switch  210  for the lamp  100 , which may be a surgical or diagnostic lamp. The bypass switch  210  may be configured for use during emergencies, when the lamp  100  may be inoperable due a failure related to the control board  214 . 
     In routine operation, the dimmable light sources  204  are configured to receive electrical power from the fuse board  208 . A matter of which of the plurality of light sources  204  receives electrical power and the quantity of power may be determined, at the fuse board  208 , based on control signals received, at the fuse board  208 , from the control panel  214 . The control panel  214  may generate such control signals, based upon manipulation by a user of the lamp  100 , and transmit such control signals to the fuse board  208 . More particularly, the control signals from the control panel  214  may be implemented as pulse width modulated signals, with the width of the pulse being representative of a degree to which individual ones of the dimmable light sources  204  are to be dimmed. Indeed, the degree of dimming may range from 0% to 100%. Elements (not shown) of the circuitry of the fuse board  208  control the degree of dimming of the individual ones of the dimmable light sources  204  based upon the control signals received from the control panel  214 . 
     As stated hereinbefore, it is generally unlikely that the control board  214  is immune to failure. Failure of the control board  214  may lead to apparent inoperability of the lamp  100 . 
     Upon detecting apparent inoperability of the lamp  100 , a user of the lamp  100  may activate the bypass switch  210 . The user of the lamp  100  may, for example, activate the bypass switch  210  by pressing the button  220  (see  FIG. 3 ) on the swing arm  304 . 
     The bypass switch  210 , responsive to having been activated, transmits an override signal to the fuse board  208 . At the fuse board  208 , the effect of receipt of the override signal from the bypass switch is to allow the electrical power provided by the power source  212  to bypass the elements of the circuitry of the fuse board  208  that control the degree of dimming of the individual ones of the dimmable light sources  204  such that the electrical power proceeds to the plurality of light sources  204  with 0% dimming. As a result of not passing through elements of the circuitry of the fuse board  208 , the electrical power provided to the plurality of light sources  204  lacks any attenuation (dimming) or individual light source control. As such, responsive to activation of the bypass switch  210 , all of the light sources  204  may be configured to turn on and glow at full power. 
     Further responsive to activation of the bypass switch  210 , the light ring  222  may be illuminated, thereby providing an indication that the bypass switch  210  has been activated. 
     Accidental activation of the bypass switch  210  may not be possible to avoid. However, through the illumination of the light ring  222 , a user can readily observe whether the bypass switch  210  has been activated. Such an observation may serve as a clue as to why the lamp  100  is not reacting appropriately to user attempts at control via the control board  214 . 
     Conveniently, when mounted on the swing arm  304 , the bypass switch  210  is easily accessible. Other easily accessible locations are also contemplated, including on the lamp head  106  or any other connecting components. 
     The above-described implementations of the present application are intended to be examples only. Alterations, modifications and variations may be effected to the particular implementations by those skilled in the art without departing from the scope of the application, which is defined by the claims appended hereto.