fig1 ( a )- 1 ( f ) present several views illustrating a handle 100 of an exemplary led curing light embodying the principles of the present invention . fig1 ( a ) presents a perspective view of the handle 100 . fig1 ( b ) and 1 ( d ) respectively present top and bottom elevation views of the handle 100 . fig1 ( c ) and 1 ( f ) respectively present right side and left side views of the handle 100 , and fig1 ( e ) presents a front view of the handle 100 . the handle 100 includes a gripping portion 10 for an operator to hold the handle 100 . the gripping portion 10 encloses , for example , electrical circuit and battery components of the handle 100 ( not shown ), and provides access to a switch button cover 11 for operating the curing light . the handle 100 also houses at least one visual indicator 12 ( for example , comprising an led ) for indicating a current state or status of the curing light . extending from the gripping portion of the handle 100 is a probe portion 13 of the handle 100 that has a diameter reduced from a diameter of the gripping portion 10 , and includes an angled bend 14 near a distal end 15 of the probe portion 14 in order that the distal end 15 may be conveniently positioned , for example , within a dental patient &# 39 ; s mouth . this configuration enables a lens assembly 16 at the distal end 15 of the probe to be placed in close proximity to a patient &# 39 ; s tooth , so that light emitted at the distal end 15 of the probe portion 13 may be used to cure a dental material that has been applied to the tooth . fig2 provides an exploded view of the curing light handle 100 , including right housing case 101 , a left housing case 102 , an led / heat sink subassembly 20 , and an optical choke 16 a and a ball lens 16 b positioned in proximity to an led 21 . the ball lens 16 b is configured to be removable and replaceable . optical choke 16 a and a ball lens 16 b are selected so that the led 21 produces a focused light output at the distal end 15 of the probe portion 13 . fig2 also illustrates a curing light circuit board assembly 30 , electrically coupled to each of the led 21 , a battery 41 , and a battery charging terminal 42 of the handle 100 . a switch button cover 11 made of neoprene or some like material covers an operating switch 31 mounted on the circuit board 30 , and protrudes through the cases 101 , 102 to provide external means for operating the curing light . an indicator cover 12 a and a light pipe 12 b are positioned over an indicator led on the circuit board assembly 30 . indicator cover 12 a protrudes from the circuit board assembly 30 through the cases 101 , 102 . audio circuitry ( not shown ) for producing an audible indicator ( for example , a “ beep ”) is also positioned on circuit board assembly 30 . fig3 ( a )- 3 ( d ) present several views illustrating a heat sink 22 of the led / heat sink subassembly 20 , for dissipating heat primarily generated by the led 21 of fig2 . fig3 ( a ) presents a perspective view of the heat sink 22 . fig3 ( b ) and 3 ( d ) respectively present top and bottom elevation views of the heat sink 22 , and fig3 ( c ) presents a side view of the heat sink 22 . the heat sink 22 conforms to an inner volume of the probe portion 13 of fig1 , and substantially fills this inner volume . preferably formed in a single piece , it extends through the angled bend 14 of the probe portion 13 of fig1 in order to be directly and thermally coupled to the led 21 of fig2 . the heat sink 22 includes , for example , lateral grooves 23 on opposing sides of heat sink 22 for directing electrical wires from the led 21 of fig2 to the circuit board assembly 30 of fig2 . heat sink 22 is also includes notches 24 on opposing sides of heat sink 22 at a distal end 25 of the heat sink in order to locatably couple the led 21 at the distal end 25 the heat sink 22 preferably comprises a highly thermally conductive material such as copper 101 . fig4 ( a )- 4 ( d ) provide several views of a ball lens 16 b affixed to the curing light handle for focusing light emitted by the led . fig4 ( a ) presents a perspective view of the ball lens 16 b . fig4 ( b ) and 1 ( c ) respectively present top and bottom elevation views of the ball lens 16 b , and fig4 ( c ) presents a section view through section a - a of fig4 ( c ). the ball lens 16 b , in conjunction with the optical choke 16 a illustrated in fig2 , further focuses a light beam emitted by the led 21 of fig2 . ball lens 16 b and optical choke 16 a are selected so that a majority of the emitted light energy is concentrated over an area that is sufficient for curing dental composites in a patient &# 39 ; s mouth . fig5 ( a )- 5 ( d ) and 6 ( a ), 6 ( b ) respectively illustrate features of left housing case 102 and a right housing case 101 , respectively . the right housing case 101 and left housing case 102 may be mated for example by ultrasonic welding . an energy director 102 a of the left housing case 102 includes an outwardly extending v - shaped edge 102 b ( see , e . g ., section f - f of fig5 ( a ), 5 ( b )) that may be positively located and mated to a corresponding groove ( not shown ) in the right housing case ( see , e . g ., section b - b of fig6 ). in addition , the v - shaped edge of the energy director is periodically relieved by an inwardly extending v - shaped groove 102 c ( see , e . g ., detail g of fig5 ( c )) that in order to receive a weld lock 101 b of the left housing case ( see , e . g ., detail h of fig6 ( b )). in this manner , the left housing case and right housing case can be easily , precisely and fixedly aligned for mating during the ultrasonic welding process . once ultrasonically welded , the left housing case and right housing case form a rigid , one - piece housing for the handle . fig7 presents a schematic diagram of a circuit 700 for operating the curing light handle . the circuit 700 is preferably powered by a conventional lithium battery ( illustrated as battery 41 of fig2 ), but may alternatively be powered by a conventional nickel cadmium battery , or alternatively , by a nickel metal hydride battery . switch 701 signals switching controller 702 via microcontroller 703 to turn on led 21 for a predetermined curing cycle ( for example , sixty seconds ). microcontroller 703 is coupled to crystal oscillator 704 to provide timed control functions . after completion of the curing cycle , microcontroller 703 removes power from led 21 to allow the curing light to enter a sleep mode . during operation of led 21 , microcontroller 703 periodically outputs a signal on pin 1 of microcontroller 703 ( for example , every ten seconds ) to cause speaker 705 to produce a regularly timed audible beep . these beeps may be used by a dentist or other operator of the handle 100 of fig1 to determine an elapsed time , and thereby to apply the curing light to cure a dental material for a desired curing time . a charging circuit 706 and fuse 707 regulate battery charging and prevent the battery from being overcharged . microcontroller 703 is further programmed to periodically test for adequate battery voltage and excessive operating temperature ( for example , every five seconds ). for example , microcontroller 703 determines the adequacy of battery voltage vdd by measuring and comparing vdd as supplied to the circuit 700 to a fixed voltage reference measured across diodes 708 , 709 . microcontroller 703 further determines operating temperature by measuring a voltage drop across a resistive component of thermistor 710 relative to vdd . as the voltage drop across the thermistor is a function of vdd , a dimensionless ratio of these two voltages may be produced to determine a relative measure of operating temperature . if either battery voltage is determined to be inadequate and / or operating temperature is determined to be excessive , microcontroller 703 does not permit a new operating cycle to begin in response to an operation of switch 701 . if an operating cycle is in progress when battery voltage is determined to be inadequate and / or operating temperature is determined to be excessive , microcontroller 703 allows the currently operating cycle to complete before preventing initiation of subsequent operating cycles . while battery voltage and operating temperature are at proper levels for operation , microcontroller 703 controls a voltage at pin 6 to light indicating led 711 . in order to provide for change and upgrading of its operating program , microcontroller 703 may further be coupled to programming connector 712 . fig8 presents a schematic diagram of a charging circuit 800 for charging battery 41 of fig2 by means of base 200 of fig9 . as illustrated in fig8 , linear regulator 801 regulates a voltage supplied to the charging circuit 800 ( for example , from a commercial power source ). so long as adequate commercial power is supplied , green led 802 lights to provide an indication that commercial power is present . as significant current is drawn at lead j 2 for recharging the battery , a voltage drop across resistors 803 , 804 activates amplifiers 805 , 806 to cause current flow through transistor 807 in order to light the red led 808 to indicate that the battery is recharging . fig9 ( a ), 9 ( b ) respectively provide exploded views of components of a base 200 for receiving the curing light handle from above and below the base 200 . the components of base 200 include a main housing 201 , a lower housing 202 , a circuit board 203 including a battery charger pin assembly 203 a and a power receptacle 203 b , and a weight 204 for stabilizing the circuit board . fig1 provides orthographic and perspective views of the base . the components 201 - 204 may be assembled together using a variety of conventional fastening means ( for example , by means of retaining pins 205 which may be ultrasonically welded , glued or thread mounted to receptacles 206 . fig1 ( a )- 10 ( g ) further illustrate the base 200 . fig1 ( a ) presents a perspective view of the base 200 . fig1 ( b ) and 10 ( c ) respectively present top and bottom elevation views of the base 200 . fig1 ( e ) and 10 ( g ) respectively present right side and left side views of the base 200 . fig1 ( f ) presents a front view of the base 200 , and fig1 ( g ) provides a rear view of the base 200 . main housing 201 includes a conical portion 201 a having a recess 201 b for receiving the gripping portion of the handle for storage and re - charging of the handle . the conical portion 201 a and recess 201 b are co - axially oriented slightly away from a vertical angle 201 c ( for example , approximately 10 to 15 degrees ). a slit 201 d extends through the conical 201 a portion into the recess 201 b , and terminates at a lowest portion 201 e of a base of the conical portion 201 a in order to enable moisture collecting within the interior of the recess 201 b to drain away through the slit . at least two charging pins in charging pin assembly 203 a of fig9 extend upward from the recess near the base of the conical portion 201 a for contact with battery charging terminal 42 of fig2 at the of handle 100 . the charging terminal 42 includes at least two , electrically isolated conductive rings ( not shown ). when the handle is inserted into the recess , each pin makes electrical contact with one of the conductive rings , regardless of the radial orientation of the handle in the recess . appendix 1 provides a program listing illustrating for example the manner in which microcontroller u 2 of fig7 is operated to measure battery voltage and thermistor temperature , and therefrom to control operation of the curing cycle and lighting of the visual status indicator . the foregoing describes the invention in terms of embodiments foreseen by the inventor for which an enabling description was available , notwithstanding that insubstantial modifications of the invention , not presently foreseen , may nonetheless represent equivalents thereto . appendix 1 ;********************************************************************** ; program for the led curing light * ; microcontroller used is the 8 pin pic12f675 . * ; * ;********************************************************************** ; * ; filename : ledcure_vx . asm * ; date : february 20 , 2003 * ; file version : 03032716 ( yymmddhh ) * ; * ; author : douglas j . mansor * ; company : coltene / whaledent , inc . * ; * ; * ;********************************************************************** ; * ; files required : p12f675 . inc * ; * ; * ; * ;********************************************************************** ; * ; notes : * ; * ; * ; * ; * ;********************************************************************** ; list p = 12f675 ; list directive to define processor # include & lt ; p12f675 . inc & gt ; ; processor specific variable definitions ; errorlevel − 302 ; suppress message 302 from list file ; —— config _cp_on & amp ; _wdt_off & amp ; _mclre_off & amp ; _pwrte_off & amp ; _lp_osc & amp ; _boden_off ; ‘ —— config ’ directive is used to embed configuration word within . asm file . ; the lables following the directive are located in the respective . inc file . ; see data sheet for additional information on configuration word settings . ; ; ;***** variable definitions w_temp equ 0x50 ; variable used for context saving status_temp equ 0x51 ; variable used for context saving ; state equ 0x20 ; state machine indicator overtemp equ h ‘ 0000 ’ ; hot bit in state undervoltage equ h ‘ 0001 ’ ; low voltage bit in state lighton equ h ‘ 0002 ’ ; light on bit in state ; time equ 0x21 ; timer overflow count , 10s count therh equ 0x22 ; high temperature byte therl equ 0x23 ; low temperature byte voffh equ 0x24 ; battery voltage with light off , high byte voffl equ 0x25 ; battery voltage with light off , low byte vonh equ 0x26 ; battery voltage with light on , high byte vonl equ 0x27 ; battery voltage with light on , low byte accumh equ 0x30 ; accumulator , high byte accuml equ 0x31 ; accumulator , low byte accumb equ 0x32 ; accumulator b . counts cycles of beep . temp1 equ 0x33 ; temporary register storage 1 temp2 equ 0x34 ; temporary register storage 2 loopctr1 equ 0x35 ; for counting mainloops loopctr2 equ 0x36 ; for counting loops vminl equ 0x80 ; coresponds to 3 . 5v with 1 . 44v ref . loops equ 0x20 ; delay 32 × 256 loops tens equ 0x6 ; light on time in 10s intervals sec5 equ 0x5f ; for 5s timing . 32768khz osc = 122 . 07us cyc ; 256 * 160 * 122 . 07031us = 5s , 160d = a0h ; ffh − a0h = 5fh tmr1seth equ 0d7h ; the high byte of timer1 preset for 10s tmr1setl equ 0ffh ; the low byte of timer1 preset for 10s ; for prescaler = 1 : 8 and fosc = 32768 hz ; ; ;********************************************************************** org 0x000 ; processor reset vector goto main ; go to beginning of program ; ; org 0x004 ; interrupt vector location movwf w_temp ; save off current w register contents movf status , w ; move status register into w register movwf status_temp ; save off contents of status register ; ; ; interrupt code can go here or be located as a call subroutine elsewhere ; ——————————————— clrf pir1 ; clear irq flags movlw 0c0h ; enable peripheral irqs movwf intcon ;& amp ; disable timer 0 irq and external irq ; verify state btfsc state , lighton ; is the light on ? goto irq_ok ; the light is on and being timed call stopall ; the timer isn &# 39 ; t supposed to be running ! goto irq_return ; stop it and exit irq irq_ok : movlw tmr1seth ; load with 10240 counts at 976 . 562us movwf tmr1h ; before next irq movlw tmr1setl movwf tmr1l decfsz time , 1 ; bump 60s time keeper goto not60yet ; maximum on time has been reached . call stopall ; subroutine to turn off big led and stop timer not60yet : call beepone ; execute a beep bcf pir1 , tmr1if ; clear the timer 1 irq flag ; irq_return : ; ——————————————— movf status_temp , w ; retrieve copy of status register movwf status ; restore pre - isr status register contents swapf w_temp , f swapf w_temp , w ; restore pre - isr w register contents retfie ; return from interrupt ; main : ; ;---------- initialize ------------- ; setup gpio , 2 , 3 ( pins 5 , 4 ) as input , ; 0 , 1 , 4 , 5 ( pins 7 , 6 , 3 , 2 ) as output , ; analog mode off bcf status , rp0 ; bank 0 clrf gpio ; init gpio movlw 07h ; set gp & lt ; 2 : 0 & gt ; to movwf cmcon ; digital i0 ( turn off the comparator ) bsf status , rp0 ; bank 1 movlw 039h ; set gp & lt ; 5 : 4 : 3 : 0 & gt ; as inputs ( 0 = out , 1 = in ) movwf trisio ; and set gp & lt ; 2 : 1 & gt ; as outputs movlw 00h ; don &# 39 ; t turn on any weak pullups movwf wpu ; gp3 doesn &# 39 ; t have a pullup clrwdt ; clear the doggie movlw 87h ; disable weak pullups and gp2 not clk source movwf option_reg ; setup option register . enable timer0 & amp ; / 256 clrf iocb ; disable interrupts for input changes movlw 01h ; enable a / d 0 ( pin7 ) & amp ; a / d clock = fosc / 2 movwf ansel ; disable the other a / d inputs movlw 01h movwf pie1 ; enable timer 1 overflow interrupt bcf status , rp0 ; bank 0 bsf gpio , 2 ; turn on the weak pullup for gp2 movlw 81h ; right justify output , vdd = ref movwf adcon0 ; select ad0 , turn on a / d power movlw 0c0h ; enable peripheral irqs movwf intcon ;& amp ; disable timer 0 irq and external irq ; and port change irq clrf pir1 ; clear irq flags clrf tmr1l clrf tmr1h movlw 31h ; 1 : 8 prescale , timer 1 on movwf t1con ; and timer 1 gate enabled clrf state clrf time ; ; beginhere : ; this is where the program will actually start . ; some setup items will occur before getting into the main loop ; ; clear first half of ram ( should disable irq first ?-----------) movlw 20h ; initialize pointer movwf fsr ; to point at ram next : clrf indf ; clear the indf register incf fsr , 1 ; increment the pointer btfss fsr , 6 ; maybe done ? goto next ; no , keep at it bsf gpio , 1 ; green off bsf gpio , 2 ; big led off ; movlw loops ; reset the loop counter ; movwf loopctr2 ; to “ loops ” value ; setup timer 0 for temperature and voltage checking movlw sec5 ; get the preset value movwf tmr0 ; into timer 0 ; mainloop : btfss gpio , 3 ; test gp3 for a low condition ( pin 4 ) goto buttondown ; perform button down sequence ; incfsz loopctr1 , 1 ; don &# 39 ; t check temp & amp ; vcc very often ; goto mainloop ; delay 256 loops ( might need more ) ; decfsz loopctr2 , 1 ; delay up to 65768 loops ; goto mainloop ; more loops ; movlw loops ; reset the loop counter ; movwf loopctr2 ; to “ loops ” value ; check the 5 second timer for temperature and voltage checking movf tmr0 , 0 ; get the current timer 0 value addlw 1 ; bump the count to get off dead center sublw sec5 ; sec5 - tmr0 . sets carry unless overflow btfss status , c ; skip next if no carry ( carry ; c = 0 ) goto mainloop ; go loopy movlw sec5 ; get the preset value movwf tmr0 ; into timer 0 ; clrwdt ; clear the prescaler ; test t & amp ; v btfsc state , lighton ; check if light is on goto lightison call convert1_off ; since light is off , read off battery voltage ; test that battery voltage is high enough btfsc voffh , 1 ; test bit 1 of off voltage . high = battery too low goto low_battery ; flag the low battery signal btfss voffh , 0 ; check the 0 bit of off voltage . 0 = high volts goto high_batt ; if bit 0 = 1 , must test the low byte movlw vminl ; get the minimum vcc limit subwf voffl , 0 ; compare with the minimum acceptable voltage btfsc status , c ; if c = 0 then voltage is ok goto low_battery high_batt : ; clear the low battery flag and light green light bcf state , undervoltage ; voltage ok goto mainloopskp1 low_battery : bsf state , undervoltage ; voltage too low goto mainloopskp1 lightison : call convert1_on ; read light - on battery voltage ; test that battery voltage is high enough btfsc vonh , 1 ; test bit 1 of on voltage . high = battery too low goto low_battery ; flag the low battery signal btfss vonh , 0 ; check the 0 bit of on voltage . 0 = high volts goto high_batt ; if bit 0 = 1 , must test the low byte movlw vminl ; get the minimum vcc limit subwf vonl , 0 ; compare with the minimum acceptable voltage btfsc status , c ; if c = 0 then voltage is ok goto low_battery ; if low goto high_batt ; if high mainloopskp1 : ; check diode temperature call convert0 ; read temperature call checkstate goto mainloop buttondown : btfsc gpio , 3 ; is the button still down ? goto mainloop ; if not down btfsc gpio , 3 ; check button a third time goto mainloop ; if not still down ; only turn on the big led if state = 0 clrw iorwf state , 0 ; check if state = 0 btfsc status , z ; zero flag is 0 if state /= 0 goto turnon ; go turn on the big led btfss state , lighton ; is the big led on ? goto release_wait ; if not , can &# 39 ; t turn it on ; turn off the big led call stopall ; lights off , timer stop , flags clear goto release_wait turnon : bcf gpio , 2 ; turn on the big led bsf state , lighton ; set the led on flag ; start timer 1 movlw tmr1seth ; load with 10240 counts at 976 . 562us movwf tmr1h ; before next irq movlw tmr1setl movwf tmr1l movlw tens ; prep time for count of 10s periods movwf time ; set the time counter bcf pir1 , tmr1if ; clear any pending irq flag from timer 1 bsf status , rp0 ; bank 1 bsf pie1 , tmr1ie ; be sure timer 1 irq is enabled bsf intcon , gie ; global irq enabled bsf intcon , peie ; peripherial irq enabled bcf status , rp0 ; bank 0 bsf t1con , tmr1on ; enable timer ; movlw loops ; reset the loop counter ; movwf loopctr2 ; to “ loops ” value ; clrf loopctr1 ; to count idle loops & amp ; sync w / beeps ; synchronize the 5 second timer movlw sec5 ; get the preset value movwf tmr0 ; into timer 0 clrwdt ; clear the prescaler call beepone ; execute a beep ; release_wait : btfss gpio , 3 ; test gp3 for high goto release_wait ; loop if still low btfss gpio , 3 ; test gp3 for high goto release_wait ; loop if still low btfss gpio , 3 ; test gp3 for high goto release_wait ; loop if still low goto mainloop ; go back to main looping when released ; loophere : goto loophere ; tightloop , wait for reset or irq ; ; ; -------- subroutines ------------ beepone : clrf accumb ; clear the ls count location beeploop : bsf gpio , 1 ; 1 start by pulling the line high bcf gpio , 1 ; 1 clear the output decfsz accumb , 1 ; 1 bump the counter and test , skip if zero goto beeploop ; 2 keep at it ; call convert1_on ; read vcc with light on bsf gpio , 1 ; green off call checkstate ; control the green led state ; reset the 5 second timer before it goes off movlw sec5 ; get the preset value movwf tmr0 ; into timer 0 ; clrwdt ; clear the prescaler ; ; movlw loops ; reset the loop counter ; movwf loopctr2 ; to “ loops ” value ; clrf loopctr1 ; to count idle loops & amp ; sync w / beeps return ; when done 255 cycles * 7 inst cycles = . 218s ; convert0 : ; a / d conversion on input ad0 to measure temperature of thermistor ; result is left in adresh and adresl bcf gpio , 1 ; pull the other side of the reference low ; lights the green led also bsf adcon0 , 1 ; start the conversion convert0_wait : btfsc adcon0 , 1 ; check for done goto convert0_wait ; keep checking til done call checkstate ; control the green led state movf adresh , 0 ; save temperature in therh , therl movwf therh bsf status , rp0 ; bank 1 movf adresl , 0 movwf therl bcf status , rp0 ; bank 0 btfss therh , 0 ; check for overtemp (& gt ; 90c ) bsf state , 0 ; set over temperature flag if maybe high btfsc therh , 1 ; check high order bit bcf state , 0 ; clear over temperature flag if sure heat is ok return ; when done ; ; ; convert1_off : ; a / d conversion on input ad1 to measure battery voltage ; with the light off . ; result is left in voffh and voffl bsf status , rp0 ; bank 1 bsf trisio , 1 ; change gp / ad1 from output to input ( pin 6 ) bsf ansel , ans1 ; make ad1 active bcf trisio , 0 ; change gp0 ( pin 7 ) from input to output bcf status , rp0 ; bank 0 bcf gpio , 0 ; pull pin 7 low ( gp0 ) bsf adcon0 , chs0 ; select pin 6 , ad1 for conversion bsf adcon0 , go ; start the conversion convert1_off_wait : btfsc adcon0 , not_done ; check for done goto convert1_off_wait ; keep checking til done movf adresh , 0 ; save temperature in therh , therl movwf voffh ; get the high bits bsf status , rp0 ; bank 1 movf adresl , 0 ; a / d low byte and trisio are in bank 1 movwf voffl ; get the low byte bcf trisio , 1 ; change pin 6 back to output bsf trisio , 0 ; change gp0 ( pin 7 ) back to input bcf ansel , ans1 ; inactivate ad1 bcf status , rp0 ; bank 0 bcf adcon0 , chs0 ; reselect ad0 return ; when done ; convert1_on : ; a / d conversion on input ad1 to measure battery voltage ; with the light on . ; result is left in vonh and vonl bsf status , rp0 ; bank 1 bsf trisio , 1 ; change gp / ad1 from output to input ( pin 6 ) bcf trisio , 0 ; change gp0 ( pin 7 ) from input to output bsf ansel , ans1 ; make ad1 active bcf status , rp0 ; bank 0 bcf gpio , 0 ; pull pin 7 low ( gp0 ) bsf adcon0 , chs0 ; select pin 6 , ad1 for conversion bsf adcon0 , go ; start the conversion convert1_on_wait : btfsc adcon0 , not_done ; check for done goto convert1_on_wait ; keep checking til done movf adresh , 0 ; save temperature in vonh , vonl movwf vonh bsf status , rp0 ; bank 1 movf adresl , 0 movwf vonl bcf trisio , 1 ; change pin 6 back to output bsf trisio , 0 ; change gp0 ( pin 7 ) back to input bcf ansel , ans1 ; inactivate ad1 bcf status , rp0 ; bank 0 bcf adcon0 , chs0 ; reselect ad0 return ; when done ; ; checkstate : bcf temp1 , 1 ; default to green - on . btfsc state , overtemp ; is diode too hot ? bsf temp1 , 1 ; green - off if hot . btfsc state , undervoltage ; is battery too low ? bsf temp1 , 1 ; green - off if battery is low . btfsc temp1 , 1 goto ckstate_set bcf gpio , 1 ; green on goto ckstate_done ckstate_set : bsf gpio , 1 ; green off ckstate_done : return ; ; stopall : ; turn off the big led bsf gpio , 2 ; turn big led off ; stop timer 1 bcf t1con , tmr1on ; stop timer 1 bcf pir1 , tmr1if ; clear the irq flag ; bcf state , lighton ; clear the led on flag call checkstate ; set / reset the green led call beepone ; execute a beep return ; ; end ; directive ‘ end of program ’
a portable led curing light for dental applications includes a one - piece handle assembly with an angled light - producing end for positioning within a patient &# 39 ; s mouth for curing a dental material . a replaceable lens for focusing light emitted by an led light source is removably attached at the light - producing end . the handle also includes a battery and associated electronics for operating the light , including an operating switch , an audible indicator and at least one visual indicator . the handle is coupled with a base for storage and recharging , which positions the handle at an inclined position for draining moisture away from the handle . circuitry in the handle monitors the status of battery voltage and handle temperature , and prevents operation of the switch from initiating a next curing cycle when battery voltage is determined to be too low or handle temperature is determined to be too high .