Hello Everyone,
This is my first post on this forum and I'm hoping someone might be able to offer me some advice, or at least let me know if I'm way out to lunch here.
I'm a bit of a noob at building circuits, I took some RC circuit design courses while I was in art school, but these were VERY basic. Recently I have been building optical square wave oscillators using 555 chips wired in astable mode and using a CDS resistor in the circuit to control pitch (frequency), these circuits are connected to speakers or an amplifier and used as audio noisemakers.
What I now want to build is a circuit that is powered by 9V dc and uses one 555 IC (or several if necessary) that would have variable frequency control and output in the audio range, somewhere in the range of 20Hz to 20Khz if possible, that can output a square wave, triangle wave and something that at least approximates a sine wave (doesn't need to be perfect). I don't mind if the frequency range is determined by a capacitor value in the circuit as I can always put in a switch to jump up or down in this range.
I've seen a post on this forum that is similar to what I want, so it seems to indicate it is likely possible, but I'm not sure how to go about making a circuit like this. The post I was looking at is here:
http://forum.allaboutcircuits.com/showthread.php?t=12405
I've read threads on other forums that seem to suggest that connecting the output of a 555 to a chain of op-amp integrators or low pass filters (are these the same thing?) can achieve this result, but I don't quite understand how to do this either. I have lots of TL082 op-amps chips lying around, would it be possible to make an integrator with one of these?
Any advice will be extremely helpful, I feeling a little lost on this cause at the moment. Thanks everybody.
kinoeye
This is my first post on this forum and I'm hoping someone might be able to offer me some advice, or at least let me know if I'm way out to lunch here.
I'm a bit of a noob at building circuits, I took some RC circuit design courses while I was in art school, but these were VERY basic. Recently I have been building optical square wave oscillators using 555 chips wired in astable mode and using a CDS resistor in the circuit to control pitch (frequency), these circuits are connected to speakers or an amplifier and used as audio noisemakers.
What I now want to build is a circuit that is powered by 9V dc and uses one 555 IC (or several if necessary) that would have variable frequency control and output in the audio range, somewhere in the range of 20Hz to 20Khz if possible, that can output a square wave, triangle wave and something that at least approximates a sine wave (doesn't need to be perfect). I don't mind if the frequency range is determined by a capacitor value in the circuit as I can always put in a switch to jump up or down in this range.
I've seen a post on this forum that is similar to what I want, so it seems to indicate it is likely possible, but I'm not sure how to go about making a circuit like this. The post I was looking at is here:
http://forum.allaboutcircuits.com/showthread.php?t=12405
I've read threads on other forums that seem to suggest that connecting the output of a 555 to a chain of op-amp integrators or low pass filters (are these the same thing?) can achieve this result, but I don't quite understand how to do this either. I have lots of TL082 op-amps chips lying around, would it be possible to make an integrator with one of these?
Any advice will be extremely helpful, I feeling a little lost on this cause at the moment. Thanks everybody.
kinoeye