Sallen Key Low Pass Filter, bandpass filter

[Maglatron]

or is it before the pre-amp and after the voltage source? right now it goes up to about 750mV

 

[Maglatron]

this is wrong, how would you do it?

 

[bertus]

Hello,

Place the voltage divider between the 45 Hz source and the preamp input.
Use a capacitor of about 10 uF between the voltage divider and the preamp input.
As the signal peaks at 0.8 Volts, use a 1:40 voltage divider.

Bertus

 

[Maglatron]

what does this mean

As the signal peaks at 0.8 Volts, u

 

[Maglatron]

correct? this is the output so I think I have it wrong again this is the wave output

 

[bertus]

Hello,

Do something like this:

Bertus

 

[Maglatron]

so now its centered about 9v and not 6(I want it centred about 6v

 

[bertus]

Hello,

Now you can adjust the gain of the preamp to get the wanted outout.

Bertus

 

[Maglatron]

ok it's working well now thanks I just need to make another 15 filters

 

[Maglatron]

in real life I'd swap this out for the mic?

 

[Maglatron]

it now tops out at 6.3volts and after the pre-amp, and then after the amplifier it tops out at 7.3 volts can you help me edit the amp so to use the full 2.4volts ie 6v to 8.4v please

 

[bertus]

Hello,

Yes, you connect the mic to the power resistor R15.
When you raise the value of R15 to 12 K, you can use the preamp on 12 Volts.

Bertus

 

[Maglatron]

so like this! also can you help me edit the amp so to use the full 2.4volts ie 6v to 8.4v please what is the fastest schottky diode in the program?

 

[bertus]

Hello,

When you connect the mic the following parts can be deleted:
V1 , R22, R18 and C18.
You can change the gain with R23.
I think you can go upto 470K for R23.

Bertus

 

[Maglatron]

cool as,and the fastest diode in spice??

 

[bertus]

Hello,

You don't need speed. You can select on voltage drop.
Shottky diodes wil have a lower voltage drop.

Bertus

 

[Maglatron]

high voltage drop seems to work better! is the 45 breakdown voltage what you are talking about

 

[bertus]

Hello,

The breakdown voltage has nothing to do with the voltage drop.
Read the wiki:

Schottky diode - Wikipedia

en.wikipedia.org

Bertus

 

[Maglatron]

Hello,

You don't need speed. You can select on voltage drop.
Shottky diodes wil have a lower voltage drop.

Bertus

Hello,

The breakdown voltage has nothing to do with the voltage drop.
Read the wiki:

Schottky diode - Wikipedia

en.wikipedia.org

Bertus

so do I aim for high voltage drop or low

 

[bertus]

Hello,

With a lower voltage drop, the evelope detector will follow the signal closer as a diode with a higher voltage drop.

Bertus