[moved] bell sound processing project.

[tapu]

Dear all,
I am designing audio project.I want to ring school bell by speaker sound.i think to use the bell sound chips which seen in Google search.but how to convert this small sound signal to large for school speaker.is it require amplifier? How to design it.or any other method to achieve the goal.

Thank you,

 

[betwixt]

Replace the loudspeaker with a resistor of about 100 Ohms than feed the voltage across it to a suitably powerful amplifier.

Brian.

 

[tapu]

Dear sir,that means I have to connect chip to amplifier through 100 ohm resistance.and output of amplifier will goes to large speaker.is it right?

 

[betwixt]

You have not explained which chip you have seen but usually they drive their own small loudspeaker directly. If that is the case, remove the loudspeaker and wire a 100 Ohm resistor where it used to be, this is because you don't want the original loudspeaker in the circuit (it will work like a poor quality microphone and give feedback) but some chips still need to see a load across their output connections. The resistor will 'fake' being a loudspeaker but with no sound of course.

Then connect the input of the large amplifier across the 100 Ohm resistor, ground to one side and input wire to the other side. The large amplifier then drives your loudspeakers.

Brian.

 

[hobbyckts]

Any IC's which you use will produce the tone or bell for making sound in order to make it very audible obviously you need amplifier circuit.

 

[Audioguru]

Why don't you post the details of the bell sound IC? I found two of them (8021-2), one has 3 pins but its datasheet does not say how to activate it and the other has 8 pins and it has a trigger input.
The 3 pins one has a datasheet labelled 1998 so maybe it is not made anymore.

It has only enough power to drive a piezo squeaker at a very low sound level so of course it needs an amplifier to drive a speaker.