LEDs washed out by sunlight

Good luck to you - those things are very scarce these days - and weren't that plentiful any days. You might build it with relay armatures to set the flags - or kluge something like the motor driven trunk actuators they use to replace solenoids.

I'm using some high efficiency LEDs on my motorcycle tach and voltmeter. They are both easily visible and in the case of the tach, my point of view is well off axis. Leds are mounted to a piece of black painted aluminum and enclosed in a clear ABS plastic dome.

The LEDs are rated at 20 ma and 3,000 mcd, 15 degree viewing angle. I put a switch on them so they could be used at night pulling 6 milliamps and found that 6 was more than enough in bright sunlight.

The voltmeter was built some time ago and I do have to have it aimed at my eyes to see the condition of the LEDs.

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IIRC they're still used in some busses to form the pixels of the route sign, and I've seen other signs using them too.

you could probably make your own by fixing an axle to a disc magnet and painting one side yellow and the other black and plasing it in a solenoid coil. LCD might be another option.

Bye. Jasen

Have you tried high intensity LED's? Maybe some 18,000mcd white or 10,000mcd red ones from

10,000 mcd green and orange ones are available enough, and blue ones of 3,000-5,000 mcd are available and more noticeable than their photometric numbers make them sound.

A 5 mm circle of white surface illuminated by noontime sunlight in June on top of Mt. Everest is about 9000-9800 mcd. That makes me think that really bright LEDs of most colors can make themselves seen anywhere. If you need a can't-fail-to-see LED, any lambertian radiation pattern type Lumileds "Luxeon" of any color at 350 mA produces a few thousand to about 15 thousand mcd from an aparent source size of a 1.6 mm square and it is not as directional as most "bullet style" LEDs. And ones of same light source size are available with higher current capabilities.

How about a blinking LED - use a 555 to blink a low power LED, or a 555 driving a MOSFET or a transistor to drive a high power one? For that matter, a blinking Luxeon should be visible at noon in June on Mt. Everest with max. output current of a "regular" 555 (100-200 mA) or the not much lower max. sink current of TLC555 and LMC555 (low current consumption ones with limited source current capability).

But for something more "passive" as in not needing to outshine sunlight

- how about something based on LCDs? The mechanical indicators suggested by another poster? How about a miniature size meter movement illuminated by a very ordinary LED to keep the meter movement visible in the dark?

How about an audible indicator? (May have to get a bit loud on a motorcycle however).

- Don Klipstein ( snipped-for-privacy@misty.com)

Whilst the torch fetish side of me likes the idea of fitting a whopping big luxeon, I will have to have a play with using filters, such as Neil's idea of using a polarised filter to improve contrast.

I have however found the following mechanical flip ball indicators

These two options comically only answer my problem for 12 hours of the day. The bright LEDs will have to be auto dimmed at night, whilst the flip balls will have to be illuminated at night.

I think I will try and fnange a sample of the flip balls.

Thanks for the replies

Marky C

D> >> >

The yellow and green for intensity setting and the blue gun separate, as it has for the millions of years beforehand There will be a 3 phase motor. It is a bit better then a belt with a wire, i need an actual collar because i also want to get 20V or even higher AC voltage.

Is it compulsory at school to be a disabled veteran? Another aspect of your government looking out for your safety.

Duh? Are you posting to the "LEDs washed out by sunlight" topic?

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