The first array in the illustrated embodiment includes a plurality of LEDs and provides a flood light illumination. The second array in the embodiment example includes at least one LED and provides a spotlight illumination. The basic circuit includes a DC supply voltage , a current selector circuit , a switching regulator circuit , and first and second arrays of light emitting devices LEDs. Optional circuits, which will be described separately, include a strobe circuit , a dimming circuit , and a low battery indicator The DC power supply includes a positive terminal and a negative terminal The positive terminal is connected to a positive supply voltage bus , which may also be called a supply bus herein.
The negative terminal is connected to a negative supply voltage bus , which may also be called a common bus herein. In the illustrative embodiment, three rechargeable, 1. The current selector circuit includes an input terminal , a common terminal , and an output terminal The input terminal is connected to the supply bus and the common terminal is connected to the common bus The switching regulator circuit includes an input terminal , a common terminal , and an output terminal The input terminal is connected to the output terminal of the current selector circuit through a node The common terminal of the switching regulator circuit is connected to the common bus The positive terminal is connected to the output terminal of the switching regulator through a node The negative terminal of the first array of LEDs is connected though a node and a series current sense resistor to the common bus The second array of LEDs includes a positive terminal and a negative terminal The positive terminal is connected to the output terminal of the switching regulator through the node The negative terminal of the second array of LEDs is connected though the node and the series current sense resistor to the common bus The current sense resistor may also be called a common current sense resistor The sense resistor may also be called a common current sense device herein because, in some embodiments, the resistor may be replaced by other elements such as an active circuit.
Working backwards through the basic circuit just assembled, a few other details will be described. The second array of LEDs includes an input terminal , which is connected through a series resistor to a drive output of the current selector circuit The signal coupled from the drive output is a control signal to be described infra.
The first array of LEDs also includes an output terminal , which is connected through a node to a sense input of the switching regulator circuit The current selector circuit includes a first control terminal and a second control terminal Connected between the first control terminal and the common bus is a first SPST switch Connected between the second control terminal and the common bus is a second SPST switch This is correct as will become apparent in the description to follow.
In the preferred embodiment, the first and second switches and are actuated with a push ON, push OFF switching action. The actuator is preferably operated by a push button.
However, in other embodiments a lever, rocking button, rotating collar, or any type of actuator having a back-and-forth travel or a repeating rotational travel may be employed. Still other embodiments may employ touch-sensitive or proximity sensitive switch mechanisms requiring no moving parts. Switches having no moving parts or latching mechanisms may require a programming feature to provide the required action described herein as will be apparent to persons skilled in the art.
As will become apparent in the description for FIG. A switch terminal on the strobe circuit is coupled to the common bus through a strobe switch also called SW 3. An output terminal of the strobe circuit is connected via a line to an input terminal of the current selector circuit The strobe circuit includes an oscillator which supplies a gating signal via the line to control the current selector circuit when activated by the strobe switch A dimming circuit may be provided as an option to control the brightness of the first or second array of LEDs.
It is available primarily as a power saving feature but may also be useful when the high brightness available from either of the LED arrays , is not needed. An example would be when the target area to be illuminated by the PLD 10 is closer than three to four meters.
The dimming circuit includes a first terminal and a second terminal The first terminal is connected to the node As will be described herein below, node is a connection point to the current sense circuit for the first and second arrays of LEDs.
A low battery indicator circuit having a positive terminal and a negative terminal , respectively connected to the supply bus at node and to the common bus , may be included in the illustrated embodiment of the PLD As will be described, the low battery indicator circuit senses the voltage available at the node and provides a visual indicator when the terminal voltage of the battery pack drops to a predetermined threshold.
Some of the structural features of FIG. Other structures in FIG. For example, the positive supply bus in FIG. Several key structures of FIG. The node provides the connection to the positive supply voltage bus , also known as the supply bus The node provides the connection to the negative supply voltage bus , also known as the common bus A capacitor connected between the nodes and absorbs transients and noise from the supply and common buses. The P-channel FET may be rated at 4.
The quad NAND gate is connected in the electrical circuit as follows. As a preliminary condition, the FET is connected in the supply bus between the nodes and as follows. The drain terminal of the FET is connected to the positive terminal of the battery via the node The gate terminal of FET is connected to the respective anodes of first and second steering diodes. The positive supply or Vcc terminal 14 of the quad NAND gate is connected to the supply bus at node Node is connected to a node Node is connected to the supply bus through a pull up resistor , and also to the output pin 3 of a gated oscillator integrated circuit U 4.
The gated oscillator is part of an optional strobe circuit to be described. Without the strobe circuit in place, the node is tied to the positive supply voltage at node through the pull up resistor The pull up resistor is provided to maintain pins 2 and 13 of the first A and second B NAND gates at a logic HIGH, unless the pins 2 and 13 are required to be driven LOW by the action of a signal applied to the node to provide an auxiliary control function.
Such an auxiliary control function may include a strobe function or any other function that requires interruption of current to the illumination drive circuitry that may be included in a particular embodiment. The interruption to the drive circuitry may be timed, as for providing a strobe function, or untimed, to provide a temporary OFF condition under manual control, for example.
The operation of a strobe circuit, identified by reference number in FIG. This arrangement provides a separate, second drive signal to control the operation of the second array of LEDs. As this occurs, and as will be described, the first array of LEDs will not be activated even though it has been enabled by pressing the first switch The operation of the current selector in FIG. An exception to this condition, to be described infra, occurs when a strobe circuit is included in the circuit and has been activated.
In this way, operating current for either of the first or second LED arrays is supplied to the switching regulator by causing the FET to conduct. The usual application of this type of switch is a first state in which the contacts are disengaged, thus disconnecting the circuit path in which the switch is used, and a second state in which the contacts are engaged, thus connecting the circuit path in which the switch is used.
However, in the present invention, each of these SPST switches is sequentially operable in the first, second, and third states corresponding respectively to latched engagement of the contacts of the switch, momentary disengagement of the contacts of the switch, and latched disengagement of the first and second contacts of the switch. In this sequence, the first state contacts engaged operates to place the electric circuit in an OFF condition, the second state contacts disengaged but not latched provides activation of the electric circuit in a momentary ON condition, and the third state contacts disengaged and latched provides activation of the electric circuit in a latched ON condition.
The first state corresponds to non-operation of the switch. Pressing the push button of the switch with less pressure than necessary to cause it to latch moves the contacts from a closed engaged condition to a momentarily open disengaged condition, which is the second state.
Pressing the push button of the switch with sufficient pressure to cause it to latch moves the contacts from a closed engaged condition past a detent in the switch mechanism to a latched open disengaged condition, which is the third state. Before describing the operation of the switching regulator circuit , some characteristics of the first and second LED arrays need to be described.
In the illustrated embodiment, semiconductor light emitting diodes are selected for the light emitting devices of the PLD Typical values for the forward current and voltage in the 1 watt device are 0. Typical values for the forward current and voltage in the 3 watt device are 1.
Thus, the operating current for the first array is approximately 0. Similarly, he operating current for the second array is approximately 1. The foregoing figures for operating currents and power levels in the illustrated embodiment are typical values that conform approximately with the manufacturer's published specifications. In the illustrative embodiment, the second array may be operated at slightly higher current, for example, 1.
In one exemplary unit, the current for operating the first array is approximately 0. Further, the current for operating the second array is approximately 1. Keeping these current and voltage drop values in mind will inform the description of the switching regulator. An important feature of the switching regulator described herein is that it drives two disparate loads with constant currents from a single drive circuit. The first array of LEDs is enabled whenever current is supplied to the switching regulator The electrical circuit is arranged so that the first array of LEDs will be activated by the output of the switching regulator circuit unless the second array of LEDs is activated.
This result occurs because the voltage drop across the fewer devices in the second array of LEDs is less than the voltage drop across the greater number of devices in the first array If the second array is activated there will be insufficient voltage from the constant current switching regulator circuit to activate the first array of LEDs and the LEDs of the first array will be in an OFF condition.
To look at it another way, when the second array of LEDs is activated, it shunts current away from the first array of LEDs. The PLD 10 as described herein takes advantage of this configuration as follows. As with FIG. The switching regulator circuit of the illustrated embodiment is provided by a step-up flyback converter architecture that includes an integrated control circuit U 2 having a positive Vcc terminal pin 1 coupled to the supply bus at node and a ground terminal pin 2 node connected to the common bus An inductor , 6.
A 3 Ampere, volt, fast switching diode , is connected between the node and a node The inductor and the switching diode are connected in series with the voltage supply bus at the output of the current selector A 47 microFarad uF , 25 volt filter capacitor is connected between the node and the common bus at node , effectively the output terminals of the switching regulator Capacitor is used if it is desired to drive the first or second arrays of LEDs with a DC voltage.
However, the circuit may be operated without the capacitor Without capacitor , the switching regulator provides a pulsed drive to the arrays , of LEDs. Connected between the node and the common bus node is a first switching transistor, N-channel FET Q 2 , rated at 14 Amperes, 50 volts. The drain terminal of the FET is connected to the node and the source terminal of the FET is connected to the common bus through a very small-valued 0.
The source terminal of the FET is also connected to pin 4 a current sense terminal of the integrated control circuit The gate terminal of the FET is connected to pin 6 the drive voltage output terminal of the integrated control circuit Pin 5 a voltage feedback terminal of the integrated control circuit will be described later. In embodiments of the PLD 10 using other types of LEDs, the switching regulator circuit may be changed to match or adapt to the particular characteristics of the LEDs.
The switching regulator in the embodiment illustrated herein operates as follows. When power is first applied to the control circuit , the drive signal at the output pin 6 appears at the gate of the first FET , turning the FET N. Current ramps up through the inductor , the FET , and the series resistor , charging the inductor until the voltage across the resistor reaches 30 millivolts mV. At that point, the FET is biased OFF and the flyback action of the inductor dumps the energy stored in its magnetic field as a current through the fast switching diode , charging the filter capacitor to the peak value of the voltage available at the node Meanwhile, the circuitry within the control circuit and connected to the feedback pin 5 monitors the voltage present at pin 5.
After this time period expires, and the voltage at pin 5 falls below the mV value, the FET will be gated ON again. This sequence is repeated, which stabilizes the voltage at pin 5 of the control circuit at the mV level and the current delivered to the first or second array of LEDs is maintained at a constant level determined by the value of the inductor and the resistor values selected for the current sensing network comprising the resistors and The first and the second arrays of LEDs, along with the current sensing network will now be described before completing the description of the operation of the switching regulator circuit when performing its current regulating functions.
The first array of LEDs in the illustrative embodiment is a series circuit connected between a node and the common bus at the node The series circuit includes a string of four light emitting diodes of like characteristics connected to be forward biased between the node and a node The anodes of the string of the light emitting diodes are all oriented toward the node and the cathodes are oriented toward the node A lead or terminal connects the anode of the uppermost light emitting diode to the node A current sense resistor is connected between the node and through a terminal to a node A common current sense resistor is connected between the node and the common bus at node A third sense resistor is connected between the node and the node to the node The node is connected to the feedback pin 5 of the control circuit via the node The feedback voltage at pin 5 is developed as follows.
The resistor is a common current sense resistor, developing a voltage drop proportional to the currents in both the first and the second arrays of LEDs. A second sense resistor , in series with the first array of LEDs and the common sense resistor , provides a voltage at the node , which is sensed at pin 5 through a resistor and the nodes and Pin 5 of the control circuit is high impedance point in the circuit; thus, resistor has little effect on the current sensing during normal operation.
The dimming circuit may be provided as an option to control the brightness of the first or second array of LEDs for saving power or limiting brightness of output illumination of the PLD In operation, under normal operating conditions without dimming the light output, the feedback voltage at pin 5 of the control circuit is approximately millivolts.
Closing the contacts of the dimming switch drives a current through the resistor , thus increasing the voltage drop across the resistor The strobe circuit of FIG. Typical Flux lm 80 85 73 66 77 80 95 Forward Current mA By selecting the light engine with the color temperature and the optical beam pattern appropriate for the application, a system can be assembled together with a heat sink for a complete solution.
Suitable applications for this 7-LED module include downlights, spot lights and track lights. Beam Angle 9 12 19 19 24 35 45 x 9. Includes multiple LED boards connected together. Refer to Philips Lumileds AB32 for electrical isolation considerations. Drive Current mA Rena Linear Solutions Size mm 50 x 25 75 x 30 x 25 x By providing you solutions that have been developed for specific applications and with a good warranty 3 to 5 years it helps take the guesswork out of your design.
Light modules require less design work to be incorporated into your fixture. Light modules are designed for specific applications and can have a much quicker design cycle. Combine your light module with an LED power supply, heat sink, optics and incorporate it into a housing and you have a solid-state luminaire. Initial Lumens Module Input Power W 14 14 13 13 16 16 15 15 26 26 25 24 42 42 39 39 14 13 26 24 44 Input Voltage VAC Initial CRI Lumens Note: Listed part numbers are recommended solutions.
Other options are available dependent on application, contact your Future Lighting Solutions sales representative for more details.
Number of modules which can be connected in series to driver 1 2 to 4 2 to 4. Power Solutions Description Xitanium 75W 0. Passive thermal management can be used by mounting the modules directly to the interior of the luminaire casing to allow heat to be dissipated to the ambient environment.
Future Lighting Solutions offers QLED, a powerful design and simulation software tool that allows lighting designers to perform real time thermal simulations. Optical Solutions-Reflectors All applications require a specific optical distribution pattern. Future Lighting Solutions in conjunction with Alux-Luxar, a leading aluminum reflector manufacturer, can offer services in custom reflector design to meet the specifications for various applications.
Input Current mA Remote Phosphor Technology Remote phosphor technology is another approach you can take in creating your LED lighting application. The technology of remote phosphor light source element is achieved by bonding phosphor to a substrate, instead of incorporating it into the LED die package. Combining the remote phosphor plate with Royal Blue LEDs, and a mixing chamber, white light can be achieve with no visible point sources.
This approach provides a low glare system capable of higher system efficiency, increased reliability and less color shift over time. In the next few pages, you will find further details on the various components needed to form your remote phosphor solution, including: Royal Blue LEDs Remote phosphor light source element Mixing chamber Optical solutions see page 32 Thermal solutions see page 50 Power solutions see page Note: This light engine is suitable for lumens downlight applications.
For more details on other LED light engine solutions, contact your local representative. The independent phosphor emits light when excited by Royal Blue light.
Because the phosphor has been separated from the energy source and can now be made in any shape and any color, unidirectional light, hot spots, inconsistency and design limitations are no longer SSL challenges. The ChromaLit family offers several standard options in optimal shapes for a wide range of lighting applications.
Below are some of the standard product offerings we currently stock. Please contact a local representative for more details concerning the other offerings not listed below. Mixing Chamber The mixing chamber is a critical component along with the high output blue LED excitation source and high conversion efficiency ChromaLit remote phosphor.
With a properly designed mixing chamber, light sources with extremely high luminous efficacy, low glare, and uniform light output are possible. The mixing chamber in a blue LED system with remote phosphor requires a broad spectrum high reflectivity material between the blue LED s and the remote phosphor source.
With this configuration, the color and spatial mixing of the light is optimized. The output beam is then exceptionally uniform with regard to color and brightness across the exit aperture of the remote phosphor. A diffuse reflectance material as opposed to specular is recommended so that a uniform Lambertian distribution is obtained. Use of any specular reflector material is not recommended in the mixing chamber since most specular materials will have significantly lower reflectivity.
Furthermore, since the down converted rays directed back into the mixing chamber are highly diffuse already, a specular reflector will simply create a return of diffuse rays. The distance between the LED and remote phosphor is also less sensitive when using a diffuse material that creates additional ray bounces before exiting the remote phosphor.
For additional information, refer to the mixing chamber design guide on our website. An electrical drive circuit in which the required Output Voltage is greater than the Input Voltage.
An electrical drive circuit in which the required Output Voltage is at times less than and at times greater than the Input Voltage. Such a drive circuit is typically required when the LED is powered using batteries, as the battery voltage is depleted over time. A unit of measurement of Luminous Intensity, equal to the amount of light given out through a solid angle, that is to say lumens per steradian.
There are 4 pi steradians in a complete sphere. The number of steradians in a given solid angle can be determined by dividing the surface area of that portion of the sphere by the square of the radius of the sphere. The measurement of color of white light, typically measured in Kelvin K. The more reddish the light, the lower the color temperature; the more bluish the light, the higher the color temperature. A measure that defines how well colors are rendered by different light sources in comparison to a standard reference light source.
CRI varies from 0 to A circuit that provides current to the LED. Open the catalog to page 7. Open the catalog to page 8. Open the catalog to page 9. Open the catalog to page PAM 10 Pages. AP 12 Pages. APQ 13 Pages. PAM 25 Pages. Protection Products 2 Pages. The front end of the rear housing section 20 includes a seal groove as shown in FIG.
A stop limits the rearward range of travel of the front housing section 16 on the rear housing section A housing ring 18 is pressed onto the rear housing section 20 and positioned adjacent to the stop At the back end of the flashlight 10 , threads 98 on the end cap 22 are engaged with rear internal threads An end cap seal or O-ring 92 within a groove 93 on the end cap 22 seals the end cap 22 against a recess in the rear housing section A battery spring 94 grounds the negative terminal of the rear most battery to the rear housing section 20 , and forces the batteries 90 into contact with each other and with the battery contact A hole 96 through the end cap 22 allows the flashlight 10 to be mounted on a key chain, key ring or wire.
The shorter length is provided by having a shorter rear housing section and using shorter batteries The flashlight in FIG. The directivity angle generally is the included angle of the solid cone of light emanating from the LED. Outside of this solid conical angle, there is little or no light. Within the directivity angle, with most preferred LED's, the light is reasonably uniform, with some decrease in intensity near the sides or boundary of the angle. The directivity angle is specified by the LED manufacturer.
Other more powerful LEDs will soon be available, which may affect lens selection. The lens preferably has a high level of strength to better resist pressure, such as water pressure when used underwater. In general, the front or outwardly facing surface of the lens will be curved, domed, or convex, as shown in FIG.
Experimentation with LED's and lenses reveals that, in terms of flashlight performance, a specific relationship exists between the directivity angle A of the LED and the focal length of the lens f. The front housing section 16 is threaded onto the rear housing section 20 , until it comes to the stop In this position, the plunger 56 is almost entirely within the switch housing 54 , causing the switch 60 to be in the off position.
Electrical power provided from the batteries 90 through the battery contact 76 and timer circuit 70 , as well as through the rear housing section 20 , is provided to the switch As the switch 60 is in the off position, no power is provided to the LED.
To turn the flashlight 10 on, the front housing section 16 is turned counter clockwise in FIG. As the front housing section 16 moves forward, the front cap 12 , lens 14 and the lamp housing 42 move with it. The LED 50 , switch housing 54 , plunger 56 , switch 60 timer circuit 70 all remain in place, as they are supported within the switch housing tube 72 which is fixed to the rear housing section As the LED or light source 50 and lamp housing 42 move away from the switch housing 54 , the plunger 56 , biased by spring force in the switch 60 also moves forward or outwardly.
This movement causes the switch 60 to move into an on position. In the on position, the electrical power is provided to the LED To focus the light from the LED or light source 50 , the user continues to turn the front housing section A position stop on the front end of the switch housing tube 72 prevents the front housing section 16 from separating from the rear housing section When the front housing section 16 is turned to its maximum forward position where further forward movement is prevented by the stop , the lens 14 focuses the light to a maximum distance.
Referring momentarily to FIG. The threaded section 73 of the switch housing tube 72 engages with the threads 82 on the front housing section. The spanner tool 75 is inserted through the back end and is used to tighten the switch housing tube 72 in place. The rim or stop at the front end of the switch housing tube acts as a mechanical stop to prevent the front housing section from separating from the rear housing section.
The combination of the LED 50 and the lens 14 allows the flashlight 10 to focus, and also to provide a narrow direct beam of light. The focusing range of the lens 14 allows filaments of the light source, which appear in the beam, to be used as pointers or indicators.
A light beam provided by the flashlight 10 has minimal dark spots. In addition, the spot pattern produced by the flashlight 10 is nearly a perfect circle, throughout the entire range of focus. The LED or light source 50 may be provided in various colors. In general, light from the LED is focused by the lens, and no reflector is needed.
However, with some LEDs, use of a reflector, in combination with a lens, may be advantageous. If the LED used has a large directivity angle, for example, 60, 70, 80, 90 degrees, or greater, the lamp housing 42 can also act as a reflector. Specifically, the interior curved or conical surface or wall 44 is made highly reflective, e. The divergence angle of the wall 44 , or curvature, is then selected to reflect light towards the lens.
While in this embodiment the reflector formed by the surface 44 moves with the lens, a fixed reflector, e. The housing ring 18 and front cap 12 provide convenient grip surfaces for turning the front and rear housings relative to each other to switch the flashlight 10 on and off, and to focus the light beam. The housing seal 78 is the only dynamic seal in the flashlight The other seals are static. Referring to FIG.
Voltage from the battery 90 is then applied to the relay , causing the relay to close. Consequently, current flows through the LED 50 generating light. At the same time, the capacitor C 1 begins to charge. When the voltage V 1 across the capacitor C 1 reaches a trigger level, it causes the output of the amplifier which act as an inverter to cause the transistor to switch the relay off or open.
Power to the LED 50 is then interrupted, preserving the life of the battery To turn the flashlight 10 back on, the switch 60 is returned to the off position by turning the front and rear housing sections in the opposite directions.
With the switch 60 in the off position, the capacitor C 1 discharges through the resistor R 1 , returning V 1 to zero, and effectively resetting the timer circuit When the switch 60 is moved back to the on position, power is again supplied to the LED, and the flashlight is turned on to provide light.
The timer circuit 70 resets to turn off power to the LED after a preset interval. The preset interval is determined by selecting the value of C 1. By providing one or more additional capacitors and a capacitor switch , the time interval before shut off can be adjusted, or selected from two or more preset values. The switch is on or in the switch housing 54 , is typically set by the user's preference, and then remains in the shorter or longer internal position.
The second switch position can be a timer bypass option. Turning now to FIGS. Except as described below, the flashlight is similar to the flashlight 10 described above. A lens ring and a lens base have three openings for receiving or holding three lenses Each lens 14 is secured in place on the lens ring within an O-ring The lens ring and lens base are attached to each other by screw threads, adhesives, etc.
Counterbores extend into the back surface of the lens base Anti-rotation pins extend from the switch housing into the counterbores. As the switch housing is fixed to the rear housing section , the lens ring does not rotate with the front housing.
The lenses 14 in the lens ring can move longitudinally towards and away from the LED's, while staying aligned with the LED's. A Teflon Fluorine resins washer between the front housing section and the lens base allows the front housing section to rotate and slide smoothly against the lens base , as the front housing section is rotated to turn on or focus the flashlight A front cap is sealed against the front housing section with an O-ring or seal In use, as the front housing section is twisted or rotated, it moves front to back via the interaction of the screw threads and The LED's 50 remained fixed in place.
The lenses 14 move front to back, with movement of the front housing section, but they do not rotate as the lens ring and lens base are held against rotation or angular movement by the pins Consequently, light from each of the three LED's 50 can be focused with movement of the front housing section Of course, the design shown in FIGS. Turning to FIG. The switch , when closed, connects the LED 50 and the resistor R 4 directly to the battery All of the other components are bypassed.
As a result, when the switch is closed, the timer circuit is inactive or disabled, and illumination by the LED is controlled purely by the switch This design is advantageous where the user wants the flashlight to remain on until manually turned off using the switch 60 , which is actuated by turning the front housing section.
When the switch is in the open position, the timer circuit shown in FIG. With the switch open, the timer circuit automatically turns the flashlight off after a preset interval of time determined by the capacitors C 1 and
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