A Nichia 2 Watt UV LED:
This is an engineering sample and was measured by Nichia with the resulting specs:
Vf = 3.74 V (If = 500mA)
Po= 88 mW (If = 500 mA)
Peak Wave Length = 379.2 nm
Below, the LED is shown next to an inverted flood reflector that has been modified to
receive the LED.
The die can be seen in the center of the recessed reflector cup. There is a glass lens that
extends beyond the cup and under the lip of the main body. The bottom of the LED has
three isolated contacts, two of which are the cathode and anode. No idea of what the third
is for. These contacts are elevated to the same plain as a center and two additional heat
sink solder pads. This device was obviously intended for surface mount applications.
Soldering leads to these small contact points was not friendly. Arctic Sliver epoxy was used
to bond the LED to the reflector. The reflector was in turn thermally connected to the
McLux flashlight head with arctic silver grease. A BB700 constant current driver was
installed:
A single 123A cell can power this light assembly but the LED is likely underdriven.
The McLux head has been mounted on an E2 body and a Copia 168B Li-Ion battery
(3.7 V) is used as the power source:
The LED has a 1/2 angle beam of 55 degrees so the reflector is re directing some of the light.
There is no glass lens on the bezel as the LED is already protected and any lens would likely
reduce the UV transmission. An O-ring in the bezel cap as well as the Arctic Silver epoxy
seal the electronics from the environment.
Below is a beam shot about 6" from a white sheet of paper. Projected light in the visible
spectrum as well as some fluorescence of the paper, presumably shows the beam distribution
of the UV:
This high power ultraviolet LED is certainly more powerful than the 5 mm UV LED's!
Another engineering sample installed in a McLux-PR head with a Down Boy 700 driver:
A Nichia 3mm blue LED was embedded in the side of the head as an "ON" indicator light.
The 3 mm is driven at about 7 mA and is plenty bright to indicate the UV light is on.
