Types of Photoresistors

[woolysheep]

Hi,

One last question for now about the $50 robot. 

I am getting some photoresistors from digikey and am wondering what resistance I should get.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=1967023;keywords=photocell

I have no idea what is ideal and if someone could explain how to know/decide and then just tell me which ones to get it would be greatly appreciated (explanation so that I can learn how to choose).

Thanks.

[pomprocker]

Basically admin was saying to go to a Radio Shack and buy the 5 pack of CDS photoresisters, and use the two mid sized ones. Then you take a multimeter and measure in the lightest room its going to be in, and the darkest room its going to be in. Then you do the math on the photoresister tutorial page, and that will give you what resistor value to buy.

[bulkhead]

The resistance range doesn't matter too much because you can always add resistors in series/parallel to get it to the range you need.

If you can buy them locally at Radioshack because with digikey, if you don't know exactly what you want you may get something strange and unusable.

[woolysheep]

ok thanks, I live in Canada though so there is no radioshack and they don't ship to Canada.  We have the Source instead but it sometimes doesn't carry everything radioshack does, photoresistors included.

[Admin]

Any of those resistances will work fine.