Talk:Photoresistor

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May 17, 2006 Featured article candidate Not promoted
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Contents

[edit] older comments

I changed the use of "LDR" since the article has changed name. I also singularized all uses of "photoresistor". Before, the plural and singular use was heavily mixed.

The previous author used italics to emphasize the dichotemy between intrinsic and extrinsic devices. At first read, the reason for the italics is unclear, so I simply added an introductory sentence to that paragraph to make it clear that it was about to discuss the difference between those two types. In which case the italics aren't needed. - ElusiveByte 00:38, Sep 22, 2003 (UTC)

[edit] HOW TO MANUFACTOR LDR?

I AM IN TRADING BUSINESS OF PHOTORESISTORS.CAN SOMEBODY TELL ME THE PROCESS OF MANUFACTORING IT FROM CADMIUM SULPHIDE. I EXPECT A DETAILED PROCEDURE.

MR.SHARAD LONDHE/INDIA. MAIL: sharad.londhe@rediffmail.com

[edit] symbol in circuit

Hi, would anyone who knows this subject add a picture of its symbol in a circuit scheme?

Added picture of symbol alone, thought this was sufficient. Only a paint drawing done by myself, if anyone feels they can do better, be my guest. This is a symbol used in the UK as mentioned in the article, I have no idea about other countries, maybe someone who does can add further images. Wheatleya 22:44, 22 February 2006 (UTC)

[edit] PHOTOCELLS

IS THERE A WAY TO WIRE TWO 120V LINES ON ONE PHOTOCELL ?

[edit] NOT PHOTOCELLS

Can I please add that Light Dependent Resistors are not photocells. They do not create an electromotive force (e.m.f.), and as such are not cells. A photocell is used as part of a circuit that makes use of the photoelectric effect to provide a current around a circuit that is proportional to the intensity of light. However these are different from a LDR, which simply varies the resistance in a circuit based on surrounding light. To repeat, LDRs are NOT photocells. —Preceding unsigned comment added by 92.12.43.166 (talk) 21:56, 26 February 2008 (UTC)

[edit] Current produced

Hi, What's the minimum current output of a Photocell? Mail: heeroyuyuk2002@hotmail.com

[edit] Circuit symbol

I've just noticed that Frozenport changed the circuit symbol of a LDR to Image:15580.gif. I have never seen this symbol in use, at least in the UK, and so I am going to change it back to my original. However, if is aware that the other symbol is used in other parts of the world, they are welcome to reinsert it. A quick Google of "ldr symbol" suggests that rectangular form is certainly more abundant.

Following the Google link you gave, it seems that a majority of the symbols are not as you claim rectangular - in fact a majority of the rectangle shaped images come from this article! I will leave the choice of what image to use to someone else, but I have yet to find a single other place where the rectangle shape is used. --Frozenport 00:17, 9 April 2007 (UTC)
Although maybe we should compromise at this [1] --Frozenport 00:19, 9 April 2007 (UTC)

Neilgravir (talk) 21:13, 27 March 2007 (UTC)

Usual IEEE Symbol has a cirle around the rectangle with the arrows pointing to that. Tswsl1989 07:43, 28 March 2007 (UTC)

I have seen the symbol that looks like a resistor withe a oval around it on a schematic from the late 70s/early 80s, I am not sure if it is used elsewhere but I do believe it to be at least an alternate symbol so I think both pictures should be on the page -Austin 7/19/07


All 3 symbols are in use, so should be here really. The rectangle, circle and zigzag. Tabby (talk) 06:15, 3 January 2008 (UTC)

[edit] LDR voltage

hi, what is the average resistance of an LDR? say it is in a series circuit with a variable resistor, and a cell of voltage 12V.light wavelengths of 380nm (lowest) and 750nm (highest). if anyone can help asap that would be great!! 14 April 2007 —The preceding unsigned comment was added by 86.140.146.247 (talk) 10:56, 14 April 2007 (UTC).

Its hard to say what a specific circuit would use, but I have seen ones from the low 100k to several megohms. If you have the circuit and just need to check the resistance I recommend just using an ohmmeter -Austin Gibbons 22:14, 19 July 2007 (UTC)Austin 7/19/07

[edit] Similar Devices

The description here seems almost identical to a Diode and/or a photo-voltaic (solar cell). Maybe someone who understands all three of these devices could point out what they have in common and what makes them different?

Tiki God 11:28, 7 September 2007 (UTC)

[edit] Name

This should not be referred to as a "photoresistor," as far as most of the physics community is concerned. Wikipedia is the only site Google turns up after a definition-search for that word. The proper term is photoconductor—I think the page should be moved for encyclopedic purposes. Listing the synonym isn't enough. —DMCer™ 17:10, 27 February 2008 (UTC)