I have all the parts to build this circuit:
http://hop.concord.org/s1/ext/s1ed1.html
It's based on the popular 741 op-amp. The goal is to build the simplest, most sensitive, sound intensity meter. We're not interested in LEDs, etc etc. We just want our volt meter to display voltages relative to the sound level in the room. We're open to going in a new direction and dropping the 741 op-amp.
So far we cannot get any readings from the voltmeter that correspond to ambient sound levels. Instead, we get an oscillating voltage that reads 0.25v and then jumps to 0.55v, and then repeats the cycle.
The example we followed called for a 9 volt battery which we substituted for a 12 volt 500 milliamp radioshack power adapter. Did we screw ourselves there?
http://hop.concord.org/s1/ext/s1ed1.html
It's based on the popular 741 op-amp. The goal is to build the simplest, most sensitive, sound intensity meter. We're not interested in LEDs, etc etc. We just want our volt meter to display voltages relative to the sound level in the room. We're open to going in a new direction and dropping the 741 op-amp.
So far we cannot get any readings from the voltmeter that correspond to ambient sound levels. Instead, we get an oscillating voltage that reads 0.25v and then jumps to 0.55v, and then repeats the cycle.
The example we followed called for a 9 volt battery which we substituted for a 12 volt 500 milliamp radioshack power adapter. Did we screw ourselves there?