On 2006-09-19, Hedos wrote:
Hello,

1) Make a circuit with a current oscillating at a specific frequency
(which could be done with capacitors/inductors/resistors, as far as I
know.)

google for "Wein-bridge oscilator" if you want a pure tone with few harmonics.
there are transistor designs for this device as well as ones that use ICs.

but if you're wantiong it to repeatably produce the exact same frequency (like a
tuning fork) it gets tricky. I'd cheat and use a crystal oscilator driving
a tone generator chip...

2) Amplify the current in order to generate audible sound in the
speaker


There are many transistor based amplifier circuits out there, picking a good
one is hard.

3) Combine the speaker with the circuit and still be able to calculate
the oscillation frequency

As long as the amplifier has a relatively high input impedance
that will work.

Is my assumption that a simple oscillating circuit going through a
speaker in serie is enough to generate a sound? i.e. a circuit
oscillating at 440hz connected to a speaker will output what
corresponds to a middle C in music.

correct.


--

Bye.
Jasen