CLC High Pass T Filter Rotary Switch Pole count
« on: May 25, 2019, 02:39:53 AM »
Hi, after checking several schematics I´m trying to figure out why is a 3 pole rotary switch placed in most designs I´ve seen.

For example, for a CLC high pass T filter the rotary switch should connect to both capacitors for each frequency, but the multitapped inductor would share common GND with all the stages.
So, for a 6 frequency steps HP T filter, wouldn´t a 2P6T  switch be enough? Check the attached image.


Thanks
« Last Edit: May 25, 2019, 03:32:50 AM by LazyTurtle »


abbey road d enfer

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #1 on: May 25, 2019, 09:38:33 AM »
Hi, after checking several schematics I´m trying to figure out why is a 3 pole rotary switch placed in most designs I´ve seen.
Can you point to a specific example?
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #2 on: May 25, 2019, 10:15:40 AM »
I think the altec 9067b is designed following this topology...
I´ve checked several new high pass filters  based in the Altec and also think they have that topology.
« Last Edit: May 26, 2019, 06:56:17 AM by LazyTurtle »

abbey road d enfer

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #3 on: May 25, 2019, 12:57:38 PM »
I think the altec 9067b is designed following this topology...
The Westfinga high pass filter based in the Altec also has this topology...
Please post schematics, can't find them.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #4 on: May 26, 2019, 06:55:23 AM »
You can check this topic where this type of rotary switch is mentioned:

https://groupdiy.com/index.php?topic=51217.0

As you can see the switch seems to be 3 pole...but I still don´t get why...
« Last Edit: May 26, 2019, 07:07:01 AM by LazyTurtle »

abbey road d enfer

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #5 on: May 26, 2019, 07:50:13 AM »
You can check this topic where this type of rotary switch is mentioned:

https://groupdiy.com/index.php?topic=51217.0

As you can see the switch seems to be 3 pole...but I still don´t get why...
Where can I see that? There is no schematic and the pictures are extinct.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #6 on: May 26, 2019, 09:25:54 AM »
It is mentioned in the post itself.
Search for the "switch" word.

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #7 on: May 26, 2019, 09:56:42 AM »
This is the picture of a unit a built several months ago.
It is a unit bought as a DIY Kit.
This is a CLC T filter and as you can see (hope it is clear enough) the rotary switch uses three decks (yellow, black and green cables, one colour per deck).
« Last Edit: May 26, 2019, 10:14:29 AM by LazyTurtle »

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #8 on: May 26, 2019, 10:02:28 AM »
In this video you can check this DIY kit better.

https://youtu.be/hGeKeApbq0gs

As you can see this unit uses 3 decks, 1 pole per deck.


« Last Edit: May 26, 2019, 10:09:08 AM by LazyTurtle »

abbey road d enfer

Re: CLC High Pass T Filter Rotary Switch Pole count
« Reply #9 on: May 26, 2019, 12:15:04 PM »
It is mentioned in the post itself.
Search for the "switch" word.
Why not saying which post? I had to read the whole thread to find the shade of an answer in post #19.
It looks like Altec used a particular arrangement that needed a 3rd switch. See attachment.
I don't know why they would use this arrangement; I can't imagine one second their engineers overlooked the simpler 2-wafer arrangement.
My only guess (but it should be substantiated with more hard evidence) is this arrangement has less interaction between sections if there are pull-down resistors.
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.


Re: CLC High Pass T Filter Rotary Switch Pole count New
« Reply #10 on: May 26, 2019, 01:17:11 PM »
Thank you very much for all the valuable information, and sorry for the reference to the post I sent.
I thought maybe searching for "switch" in the topic you could've reached faster to the post itself.
« Last Edit: May 26, 2019, 01:41:54 PM by LazyTurtle »


 

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