mick wrote:
On Thu, 31 Jan 2008 17:44:11 +0000, George wrote:
"George" wrote in message
.uk...

Diagram here if anyone interested? it can be made up on veroboard if
you
are
not bothered about a PCB one.

The more leds on the cicuit the better the night vision.
http://www.reject.org/tsd/liz/gbppr/...v/ir_illum.pdf




Whats the best infareds for this project,Blue or Clear? as I found this
site out of a few to be a lot cheaper in price.

http://www.esr.co.uk/Optoelectronics.PDF

TA

Probably part number 720-530 on page 21. Those will give 80mW radiant
power each, if you adjust the resistors to put 100mA through each string
of LEDs. Using a 12v supply you could make R1-R8 15 ohms rather than 39
ohms. This is running them close to their maximum so perhaps a slightly
higher value may be better... Note that your total load current would be
400mA, so this isn't really for battery operation.

Why use LEDs when filament lamps radiate IR well when run at under
half rated voltage. Producing IR is the filament lamp's forte, or
weakness when you want visible.


NT