I'm working on a VCO (or would like to but I've pretty well pulled all my hair out and gotten know where so far)
First question before I get into what I'm trying to do. I've looked at many VCO schematics and some use a square wave generator and then wave shape the square into the other wave forms and some seem to have a separate generator for each wave form (triangle, square, sine, saw). Which would be the best way to go?
Any ways regardless I decided to start with wiring up a triangle waveform generator. I am new to this so forgive me if this is a trivial question.
I found a few triangle wave form circuits and they all were about the same so I decided to make this one http://falstad.com/circuit/e-triangle.html . Now the problem is I do not have a 1uF capacitor as this circuit has in it. The smallest I have is 10uF. But I do have a wide range of resistors so that's not a problem. So I substituted the 1uF for the 10uF cap in that circuit and adjusted the resistor values to produce a proper triangle wave again in the simulator on that site. Everything looked fine so I put it together on a breadboard and tested it. It didn't work.
I tried many times, rewiring and even swapping out op amps for different ones but still no luck. I now know I didn't calculate something right and or that simulator isn't accurate.
This is the circuit I built:
Voltage In DC: 6.2v
Capacitor: 10v 10uF
OP AMP: NTE859 (Quad op amp)
So I guess my question is where did I go wrong and is it even possible to change the capacitor value so drastically in this circuit?
First question before I get into what I'm trying to do. I've looked at many VCO schematics and some use a square wave generator and then wave shape the square into the other wave forms and some seem to have a separate generator for each wave form (triangle, square, sine, saw). Which would be the best way to go?
Any ways regardless I decided to start with wiring up a triangle waveform generator. I am new to this so forgive me if this is a trivial question.
I found a few triangle wave form circuits and they all were about the same so I decided to make this one http://falstad.com/circuit/e-triangle.html . Now the problem is I do not have a 1uF capacitor as this circuit has in it. The smallest I have is 10uF. But I do have a wide range of resistors so that's not a problem. So I substituted the 1uF for the 10uF cap in that circuit and adjusted the resistor values to produce a proper triangle wave again in the simulator on that site. Everything looked fine so I put it together on a breadboard and tested it. It didn't work.
I tried many times, rewiring and even swapping out op amps for different ones but still no luck. I now know I didn't calculate something right and or that simulator isn't accurate.
This is the circuit I built:
Voltage In DC: 6.2v
Capacitor: 10v 10uF
OP AMP: NTE859 (Quad op amp)
So I guess my question is where did I go wrong and is it even possible to change the capacitor value so drastically in this circuit?