Music box

Thread Starter

Quillion

Joined Jul 18, 2009
10
Ok so my brother bought some tiny ipod thing(really not ipod fan), and it had this tiny cute box, in which my small breadboard fits perfectly.
So I want to make a light sensitive music (more like annoyance) box.
Any ideas or suggestions on how I should do it?
This is my plan, but I am pretty bad at this.
So in general what I want is that the more light hits the photoresistor the louder piezo speaker starts to sound. And when there is almost no light you can barely hear it.
I am planning to use 555 chip, but if there is anything better to use please tell me. It does not have to contain 555 chip, I just want some kind of idea that will work.
 

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Thread Starter

Quillion

Joined Jul 18, 2009
10
How exactly would you use transistor?
And what kind of transistor will you use?
The problem I have been having is making piezo make noise. If I just directly connect it to the battery it makes no noise, so I end up using 555 chip.
So how should I connect transistor to it to make it work?
 

jj_alukkas

Joined Jan 8, 2009
753
A low gain pre-amp circuit with an LDR replacing the input resistor might work.

A single BC547 or 2N3904 transistor based circuit is enough. You could find one easily online and do some experimentation. I am not used to LDR's, so I dont know its Rmin and Rmax.
 

Thread Starter

Quillion

Joined Jul 18, 2009
10
I am sorry for sounding very stupid, but how would you connect it to piezo so it would buzz. Can you please provide some rough explanation as to where I connect base, collector and emitter
 

jj_alukkas

Joined Jan 8, 2009
753


This is a preamp ckt. If you can measure the LDR's resistance at max and minimum light, you can calculate the dividing resistor and place those 2 instead of the 10 k variable in this ckt. Then you will get variable output. By why do you need to run a piezeo?? A normal small speaker will work on this ckt. For piezo, you might need a capacitor in series with the output.
 

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Thread Starter

Quillion

Joined Jul 18, 2009
10
I can't get my hands on any speakers, whenever I ordered (3 times already) it came to me broken(I tried from different websites), it was back in time when I was planning to make motorcycle sounding thingie with capacitors and a potentiometer, so I simply decided to stick with piezo, since I got a store nearby that sells them 90 cents each
 
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