LDRs. I am sure this is a stupid question...

[chris_d]

But, where do you get LDRs? Do they have another name they go by? "LDR" "light detecting resistor"? Can't seem to find them at Mouser? Or am i staring right at them and not knowing it?

Thanks folks.

-chris

[CGDARK]

But, where do you get LDRs? Do they have another name they go by? "LDR" "light detecting resistor"? Can't seem to find them at Mouser? Or am i staring right at them and not knowing it?

Thanks folks.

-chris

Actually LDR stands for light-dependent resistor and is also known as photoresistor or as photocells.
Read this: http://en.wikipedia.org/wiki/Light-dependent_resistor

A lot of retailers have them. Check these at Small Bear Electronics:
http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocouplers

Good luck,

CG

[chris_d]

But, where do you get LDRs? Do they have another name they go by? "LDR" "light detecting resistor"? Can't seem to find them at Mouser? Or am i staring right at them and not knowing it?

Thanks folks.

-chris

Actually LDR stands for light-dependent resistor and is also known as photoresistor or as photocells.
Read this: http://en.wikipedia.org/wiki/Light-dependent_resistor

A lot of retailers have them. Check these at Small Bear Electronics:
http://www.smallbearelec.com/Categories.bok?category=Photocells+and+Photocouplers

Good luck,

CG

Thanks! I knew it was a silly question! Normally i know how to use google, too. Shit, i hope i am not getting lazier.

-chris

[The Tone God]

I don't think Mouser has carried LDRs for some time. I know Digikey does carry them so you can try there as well.

Andrew

[Mark Hammer]

Not a silly question.  Simply what happens when people have more than one name for the same thing.  Is a lawn different than a yard?  Is a car different than an automobile?

[oldrocker]

Bought mine at Radio Shack.

[mdh]

You'll often find them referred to as CdS (cadmium sulfide) cells. That can be handy because "cds cell" is a pretty good search term compared to "photocell" or "photoresistor" (or is that "photo cell" or "photo resistor"... see?).

[RedHouse]

Since the search function isn't working for you, here's a link to a recent thread about this very subject:

LDRs for a Neovibe? http://www.diystompboxes.com/smfforum/index.php?topic=61606.0

[CGDARK]

You'll often find them referred to as CdS (cadmium sulfide) cells. That can be handy because "cds cell" is a pretty good search term compared to "photocell" or "photoresistor" (or is that "photo cell" or "photo resistor"... see?).

From Wikipedia, the free encyclopedia
(Redirected from Light-dependent resistor)• Have questions? Find out how to ask questions and get answers. •Jump to: navigation, search

LDR
The internal components of a photoelectric control for a typical American streetlight. The photoresistor is facing rightwards, and controls whether current flows through the heater which opens the main power contacts. At night, the heater cools, closing the power contacts, energizing the street light. The heater/bimetal mechanism provides a built-in time-delay.A photoresistor or LDR is an electronic component whose resistance decreases with increasing incident light intensity. It can also be referred to as a light-dependent resistor (LDR), photoconductor, or photocell.

http://en.wikipedia.org/wiki/Light-dependent_resistor

CG

[mdh]

LDR
The internal components of a photoelectric control for a typical American streetlight. The photoresistor is facing rightwards, and controls whether current flows through the heater which opens the main power contacts. At night, the heater cools, closing the power contacts, energizing the street light. The heater/bimetal mechanism provides a built-in time-delay.A photoresistor or LDR is an electronic component whose resistance decreases with increasing incident light intensity. It can also be referred to as a light-dependent resistor (LDR), photoconductor, or photocell.[/i]

Touche, but I'm talking about searching on vendor websites, where data often seem to be entered by individuals who don't seem to know the inventory... just pointing out that it never hurts to have another, unambiguous search term.

[chris_d]

Everybody, thanks for the responses!

I have a couple further questions about them though.

What i think i want to do is use some LDRs in the place of some potentiometers, for instance in place of the two 500k pots in the Atari Punk Console, and run it off of light input instead for kicks.

Some of the LDRs list a light and dark resistance, but not all of them seem to? How do you determine what it is, aside from buying and measuring it?

Also, it looks common for the LDR to have a range between a low(but non-zero) resistance and a higher one. Is it possible for an LDR to have zero resistance at one end like a pot, or is that not how they function?

Thanks again for the input!

-chris

[chris_d]

Bought mine at Radio Shack.

aHA! My local RS only carries cellphones and audio cable these days, but your post got me to look into the RS in the next town over. It turns out they still have the components at that one. I aquired a few different light-sensing items to play with.

Excellent! Thanks! These suckers are fun. The APC is quite a bit of fun with LDRs in for the pots! Lots of possibilities for them.

Thanks again!

-chris

[Brian Marshall]

alliedelec.com has a pretty good selection along with pretty good prices.

[aloupos]

They're loads of fun, and have a lot of uses.  This is slightly off topic, but have a look: 

http://lifehacker.com/software/diy/build-a-laser-spy-microphone-on-the-cheap-292718.php

uses an LDR and a laser to capture vibrations in glass and record the audio.