Electronic filter.

For the three and more legged things
Post Reply
User avatar
pre65
Amstrad Tower of Power
Posts: 21367
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#1 Electronic filter.

Post by pre65 »

Saw this on Ebay just now.

Is it similar to the E-choke Mike H used to do ?

http://www.ebay.co.uk/itm/Tube-Preamp-A ... 1660715763
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
Michael L
Old Hand
Posts: 653
Joined: Tue Feb 19, 2013 5:10 pm
Location: Shrewsbury

#2 Re: Electronic filter.

Post by Michael L »

I was talking to MJ last Owston meet up about the pros and cons of such a circuit compared with a filter using a choke.
I admit I didn't fully understand - well I had consumed some beers.
Could someone enlighten me?
User avatar
Nick
Site Admin
Posts: 15694
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#3 Re: Electronic filter.

Post by Nick »

The circuit it there, its a cap multiplier

Image
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Mike H
Amstrad Tower of Power
Posts: 20156
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#4 Re: Electronic filter.

Post by Mike H »

Yes virtually identical to mine.

Which Nick G helped me with incidentally. :D
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Michael L
Old Hand
Posts: 653
Joined: Tue Feb 19, 2013 5:10 pm
Location: Shrewsbury

#5 Re: Electronic filter.

Post by Michael L »

Michael L wrote: Thu Mar 16, 2017 9:21 am I was talking to MJ last Owston meet up about the pros and cons of such a circuit compared with a filter using a choke.
I admit I didn't fully understand - well I had consumed some beers.
Could someone enlighten me?
Still none the wiser. I assume using a choke must have advantages because it's weight and cost are disadvantages.
User avatar
Nick
Site Admin
Posts: 15694
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#6 Re: Electronic filter.

Post by Nick »

The mosfet cap multiplier will filter the DC. A Choke will do that, but will also store energy in its flux which the SS wont do. If a choke is used in choke input, then it has the magic feature of drawing continuous AC current from the transformer.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
User avatar
Mike H
Amstrad Tower of Power
Posts: 20156
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#7 Re: Electronic filter.

Post by Mike H »

The electronic version needs an overhead of extra supply Volts, which can be quite awkward to provide. Or in other words, you lose some HT, in my one's case, about 25V minimum. So appreciably less efficient than a genuine inductor choke.
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Michael L
Old Hand
Posts: 653
Joined: Tue Feb 19, 2013 5:10 pm
Location: Shrewsbury

#8 Re: Electronic filter.

Post by Michael L »

Thanks Nick and Mike.
Colin Wonfor
User
Posts: 6
Joined: Mon Jul 27, 2015 5:20 pm

#9 Re: Electronic filter.

Post by Colin Wonfor »

Unitrode did a nice SMPSU in a high speed switcher, using current doubling which allowed us to use smaller caps with chokes, a nice design.
We re-worked it with a full resonant bridge circuit and made it RAD Hard and now they are whizzing over head in space. We also used Si plated in Gold.
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12272
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#10 Re: Electronic filter.

Post by Dave the bass »

I had to Google 'RAD Hard'!

Respekt!
"The fat bourgeois and his doppelganger"
User avatar
Mike H
Amstrad Tower of Power
Posts: 20156
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#11 Re: Electronic filter.

Post by Mike H »

Wow .. :shock:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Post Reply