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Sound Modulated LED Project Help

jeez...this is getting to be very overwhelming.

so the radio shack 276-124 cell will not work for my purposes, right? That at least seems to be the consensus.

Am I correct in thinking that the photocells included in the yard lights in the previous website will work with what I'm trying to accomplish?

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again, I want to amplitude modulate an led or any sort of light and have the sound picked up by a photocell and be played through an amp.

If this is impossible for a 13 year old to accomplish without having a vast amount of knowledge in physics and circuitry perhaps I should modify my project for something not as challenging...although i could really use a good grade.

thanks.

Reply to
fernandoleiva
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276-124 is the *correct* kind of thing. It *generates* electricity which is what this project requires. 276-142 is the *wrong* kind of thing. You get a photo-transistor detector which *doesn't* generate elctricity. It's possible to construct a circuit using such a part that'll do the job but it's more complicated.

That's not a yard light. That link is a volume control using a CdS photocell which is another type that's not suitable for your project.

That's fairly straightforward.

The trouble here is that 'photocell' is a commonly misused term. Theer are several types of 'photocell' and only one kind will do what you want here.

It would help if the original site you looked at had explained better what they were on about. The info is somewhat limited and you could easily trip up on these details.

Additionally I'll comment that a walkman's headhone output is unlikely to supply enough signal volts to modulate the transmitting led very effectively. It would be better to use a proper loudspeaker output from an amplifier.

Graham

Reply to
Pooh Bear

"Christopher"

** Oh dear - not again.

CdS cells are " light dependant resistors" with VERY SLOW response times - in the order of hundreds of milliseconds to change value when the incident light changes intensity.

A photo transistor responds to light in microseconds.

A solar cell does also.

....... Phil

Reply to
Phil Allison

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