Sallen Key Low Pass Filter, bandpass filter

[bertus]

Hello,

Read the following thread on All About Circuits:

Decoupling or Bypass Capacitors, Why?

I posted something like this a while back, but I've noticed a good number of newer members forgetting the bypass/decoupling caps in designs, or asking about their purpose in life (the caps, not the members). The reason for them is "stiffening" of the power supply. The wires on a breadboard...

forum.allaboutcircuits.com

It shows you the use of the decoupling capacitors.
They should be as close as possible to the power lines of the opamps.

Bertus

 

[Maglatron]

Ok no its not making sense to me. My initial thought was to put the capacitors over the power supply but there is only 5 circuits connected together and there are 6 capacitors to add to the circuit. do you mind "drawing them in for me?"

 

[Maglatron]

powerlines as in 12v and REF?? and where does the electrolytic go?
or 12v and actual ground?

 

[Maglatron]

Hey bertus, you're over there too!

 

[Maglatron]

My internet connection doesn't allow me to download the pdf files from allabout circuits, could you post them here please? cheers

 

[bertus]

Hello,

To download the PDF's from All About Circuits, you will need to register.
After registration, you can download all pictures and PDF's from over there.

Bertus

 

[Maglatron]

I know what they're for to mitigate dips (ripple) on the power lines

 

[Maglatron]

I am registered there, it's my internet it restricts certain sites or sometimes downloads

 

[bertus]

Hello,

It is probably the VPN that you are using thet is ginving the problems.

Bertus

 

[Maglatron]

yeah I'm in hosptal so the hospital internet restrictions are out of my control, I can't even download a VPN!

 

[Maglatron]

I can't even log into email sites, sign on to youtube, paypal, skype and have trouble accessing certain stuff, mainly helpful stuff lol, it's a pain in the neck!!

 

[Maglatron]

I got my sister to sign up to allaboutcircuits for me and this site did not require email validation at all!

 

[Maglatron]

so I think I've worked out where the four of the 100nF's go, they go the shortest route between 12v in and the REF virtual ground of the filters, now I need to know where to put the 10uF cap, but im thinking that it goes in parallel with the 100nF across the 12v and actual ground of the buffer am I right? If so will it work as soon as I know I can get on with designing all of the filters! cheers

 

[Maglatron]

The internet has no problems downloading from this site though!

Hello,

It is probably the VPN that you are using thet is ginving the problems.

Bertus

 

[Maglatron]

is it possible to change your name on allaboutcircuits because I want to call myself Maglatron

 

[kellys_eye]

I think that I pretty much have it sussed now,

I suspect your next few hundred posts might put that to the test........

 

[Maglatron]

theoretically have I got it right??

 

[Maglatron]

I suspect your next few hundred posts might put that to the test........

theoretically have I got it right?? does it matter that the stages are not in order

 

[Maglatron]

and where do the bypass filters go
View attachment 61886

so I think I've worked out where the four of the 100nF's go, they go the shortest route between 12v in and the REF virtual ground of the filters, now I need to know where to put the 10uF cap, but im thinking that it goes in parallel with the 100nF across the 12v and actual ground of the buffer am I right? If so will it work as soon as I know I can get on with designing all of the filters! cheers

Is this all correct!?

 

[Maglatron]

I can use TL074CN for the pre-amplifiyer, the filters, the buffer circuit and the enveloping detector circuit
how many buffer circuits would I need to use with 16 channels, do the LM3914 and the buffer use the same actual ground in the circuit and the signal from the enveloping detector circuit to pin 5 of the LM3914?