Buy photoresistors?

Hello,

I am working on a new project that uses a lot of photoresistors. I've looked at my usual sources (digikey, mouser) and did not find any. Am I just doing my searching wrong or am do they not carry them for some reason?

I would like to buy them from a large carrier (like digikey) as opposed to eBay, so that I can go back later and get the same part, and get datasheets.

Thanks!

The single most important part of searching for anything, is terminology =) There's more than one term for just about everything.

Try searching for photocell, Digikey pulls up a pretty good list.

Or even LDR (Light Dependent Resistor)

Thanks, the photocell search did it for me. I am kind of surprised in the pricing of those things though, I thought they were super cheap?

Try shopping around a bit, some places and parts are cheaper than others.

Fred.Amoson said:

Thanks, the photocell search did it for me. I am kind of surprised in the pricing of those things though, I thought they were super cheap?

Click to expand...

No, they are fairly expensive items.

Nigel Goodwin said:

No, they are fairly expensive items.

Click to expand...

There was my problem

Thanks

Can you use ......

Fred.Amoson said:

Hello,

I am working on a new project that uses a lot of photoresistors. I've looked at my usual sources (digikey, mouser) and did not find any. Am I just doing my searching wrong or am do they not carry them for some reason?

I would like to buy them from a large carrier (like digikey) as opposed to eBay, so that I can go back later and get the same part, and get datasheets.

Thanks!

Click to expand...

........ photo diodes? Why, because I have a large surplus.

Photocells/Light Dependant Resistors or Photo Resistors are usually Cadmium sulfide based. Photocell is a more generic description which can refer to any device that detects light. Modern compound photocells have virtually nothing to do with cadmium sulfide LDR's except an obscure linguistic link but one common enough obviously to provide a search related bias on Digikey =) Search for LDR on Digikey and it will provide a reference to 2,018 items, most are completely unrelated. Photocell provides 32 links, all exactly the device in question.

In an LDR/Photo resistor the amount of light falling on the device directly affects it's resistance.
Photodiodes are a completely different class of devices that take advantage that any PN junction (diode) will self bias when exposed to light related to the semiconductor material's specific frequency of excitation

They can be cheaply had, depends on the source. I buy the ones from Mode Electronics via one of their distributers. They make several, part numbers are 90-154-0 through 90-157-0 covering several resitance ranges.

Check the Mode Electronics website, https://www.mode-elec.com

Click on miscellaneous items in the navigation menu, a new list will appear, CDS cells are there.

Cheapest I have found anywhere by far. I get a hundred at a time at about 35 cents US each.