LED as a replacement for a light Sensor

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LED as a replacement for a light Sensor

Postby Harry Dalek » Sat Dec 17, 2011 3:27 pm

Been working with working with my opto fork using a LDR but i am finding room light light levels i have to adjust the circuit ...

I am going to swap with a light transistor type Sensor ,i have one handy but reading about most transistors and leds can do the same thing when exposed to light i have been experimenting .

I know most opto forks are I R type so this fixes the room light problem but again depends on what you have handy and if you want to make your own ...Experimenting i am finding the clear type LEDs seem to work as well as a light transistor.

Trying a high brightness white with a UV light seems to work very well ...
i tried a luxeon and it works as well on white light ,i think these things are frequency sensitive so you would have to see what works with the light frequency or its band width your trying .

Good to get 2 different things out of the same component !
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby gary » Sat Dec 17, 2011 7:16 pm

Harry, I have almost completely move to a reflective sensor with a printed out optical encoder - it seems the easiest and most versatile implementation.

http://ccrma.stanford.edu/courses/250a/ ... RB1114.pdf
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Postby Harry Dalek » Sat Dec 17, 2011 8:21 pm

gary wrote:Harry, I have almost completely move to a reflective sensor with a printed out optical encoder - it seems the easiest and most versatile implementation.

http://ccrma.stanford.edu/courses/250a/ ... RB1114.pdf


Yes it looks good wish i had one to play with ... looking at the price of some on ebay they are pretty cheap but the cheap ones do look like no more than sticking a led and light S trany side by side.
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Postby gary » Sat Dec 17, 2011 8:29 pm

harry dalek wrote:
Yes it looks good wish i had one to play with



Jaycar USED to sell them, but I am not sure they sell anything useful these days, I think I have some spare, if you like I could send you one.

harry dalek wrote: ... do look like no more than sticking a led and light S trany side by side.


Indeed, but I think they are cheaper than the cost of the individual components combined, AND they are matched correctly, AND the mechanics is already done for you - you just need to screw them to some sort of support and that's it. They are especially useful when you want the ability to easily change the position.
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Postby Harry Dalek » Sat Dec 17, 2011 9:07 pm

gary wrote:
harry dalek wrote:
Yes it looks good wish i had one to play with



Jaycar USED to sell them, but I am not sure they sell anything useful these days, I think I have some spare, if you like I could send you one.

harry dalek wrote: ... do look like no more than sticking a led and light S trany side by side.


Indeed, but I think they are cheaper than the cost of the individual components combined, AND they are matched correctly, AND the mechanics is already done for you - you just need to screw them to some sort of support and that's it. They are especially useful when you want the ability to easily change the position.


Hi gary

Yes your right there ...really the price is pretty good for something like that .
Yes i wouldn't mind one do you want to do a swap i have a fair few stepper motor drive ic's spare you might like to try .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Harry Dalek
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Postby gary » Sat Dec 17, 2011 9:14 pm

harry dalek wrote:Hi gary

Yes your right there ...really the price is pretty good for something like that .
Yes i wouldn't mind one do you want to do a swap i have a fair few stepper motor drive ic's spare you might like to try .


Sure, I love my steppers, send me a PM and we'll swap addresses.
Perfecting an NBTV system is like trying to slam a revolving door...
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Postby Harry Dalek » Sat Dec 17, 2011 9:26 pm

gary wrote:
harry dalek wrote:Hi gary

Yes your right there ...really the price is pretty good for something like that .
Yes i wouldn't mind one do you want to do a swap i have a fair few stepper motor drive ic's spare you might like to try .


Sure, I love my steppers, send me a PM and we'll swap addresses.


Hi Gary message sent i will post this week no worries .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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