Hey guys thanks for the input, it is greatly appreciated.
Im sorry if my lack of electrical education is exacerbating matters,
Hopefully, I’ll get there in the end.
Edwin is an electrical schematic and PCB design package from visionics, unfortunately, it does cost..
Info at..
http://www.visionics.a.se/
I was lead to believe it’s the industry standard, and the best to use.
Yeah Jess, those dotted lines are supposed to be ‘nets’ that indicate the actual wiring of the circuit, so yeah, your right, op amp 2 has been shorted! Unfortunately it can be temperamental with re-routing, but I’ll get right on it.
Those 2.7V readings should indeed be AC readings, but not overly sure, the op-amps are powered with DC, and the VGEN is outputting AC.
Audioguru, thankyou very much for your indepth help..
Damn, I thought my calculations where correct once I’d achieved the, rough, freq response that was required.
My original calculations where
Fc = 1 / 2 x Pi x R x C
LPF = 1 / 2 x Pi x 10k x 1 nF = 15kHz (cutting higher)
HPF =1 / 2 x Pi x 500k x 1 nF = 318Hz (cutting lower)
Are these values correct?
Once I’d implemented these, and the freq response was simulating correctly,
I then was trying to tackle the gain problem, and tried to utilise gain on the first two op-amps aswell, played around with the values of the resistors, its annoying that Edwin maintained the freq response was correct when Audioguru points out they where clearly wrong..
**broken link removed**
How does changing the ratio between the resistors for gain, effect the resistance you use for the Fc derision? I admit I am unsure how you got 2k resistance value for the HPF circuit?
Any advice on how could I combat the opposing phase shifts in each filter circuit?
Russlk – thanks for the example circuit, unfortunately, something of that complexity is well beyond my realms of understanding at this point.
I really wanted to utilise a bandpass filter, that was a simple as possible, enabling me to further my knowledge. Once I got it working, I was then going to tweak and interchange components to get further to what I actually want. So for now, flatness in the passband, and slope order can wait!