Using Mike's E-Chokes

What people are working on at the moment
Post Reply
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#1 Using Mike's E-Chokes

Post by Ray P »

I've got a few of the E-Choke boards that Mike H produced a little while back and I'm thinking I ought to give them a whirl at some point. Is there any reason why I couldn't use multiple E-Chokes to manage the load on each one; if the amp has four output valves (per channel) use two E-chokes, each providing B+ to a pair of valves or even one E-choke per valve.

In case anyone has forgotten them, here's a link to the E-Choke thread;

http://www.audio-talk.co.uk/phpBB2/viewtopic.php?t=3101

Ta muchly

Ray
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#2

Post by pre65 »

I've only used them in the amp PSU.

At the moment I have two (one per channel) in the GK-71 amp PSU.
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)
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#3

Post by Ray P »

Cheers Phil. I plan to use them in the amp PSU; it's the load on the E-choke I want to manage as all four output valves require 500mA total, which is right on the upper limit of the E-Choke without a lot of heat management and as big heatsinks aren't cheap it might be more cost-effective to use several chokes.

Ray
User avatar
pre65
Amstrad Tower of Power
Posts: 21373
Joined: Wed Aug 22, 2007 11:13 pm
Location: North Essex/Suffolk border.

#4

Post by pre65 »

Don't forget that they should not be used as the first choke in choke input configuration.
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)
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#5

Post by Ray P »

I hadn't forgotten Phil, but my next question was probably along the lines of whether they're good enough to use as a single stage filter or whether a pre-filter, either CR or CL, would be necessary or beneficial.

Ray
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#6

Post by Mike H »

If you mean use them in parallel from a common HT source, then yes.
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Steptoe
User
Posts: 76
Joined: Thu Mar 13, 2014 8:26 am

#7 using mikes e chokes

Post by Steptoe »

I have a large selection of pre loved aluminium heat sinks so if you let me know what you need I'll see if I can find some. Best wishes, Steptoe.
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#8

Post by Ray P »

Mike H wrote:If you mean use them in parallel from a common HT source, then yes.
Yes Mike, parallel E-chokes, each supplying a pair of the quad output tubes.

Would a pre-filter be beneficial, say an upstream CR stage, and if so can you suggest anything suitable. Target voltage is 180V.

Thanks for finding the time to respond.

Ray
User avatar
Mike H
Amstrad Tower of Power
Posts: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#9

Post by Mike H »

Haven't used a pre-filter with mine, unless you include choke-input. Just make sure the peak-to-peak of the input sawtooth is less than say 20V.

HTH
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#10

Post by Nick »

Mike H wrote:If you mean use them in parallel from a common HT source, then yes.
Would it be worth having something to force current sharing as each will probably regulate to its own V drop.
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: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#11

Post by Mike H »

Err, possibly? Image
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#12

Post by Ray P »

Nick wrote:
Mike H wrote:If you mean use them in parallel from a common HT source, then yes.
Would it be worth having something to force current sharing as each will probably regulate to its own V drop.
I did wonder if using multiple E-Chokes might result in small variations in the supply to each pair of valves and whether that would be detrimental but have no idea how to implement current sharing unless it is as simple as tying the outputs of the different chokes together?

Ray
User avatar
Ray P
No idea why I do this anymore
Posts: 6294
Joined: Thu Nov 22, 2007 5:18 pm
Location: Somerset

#13

Post by Ray P »

ON a related topic, the B+ supply for the input valve for the amplifier, I'm thinking that a separate shunt regulator would be good?

Ray
User avatar
Nick
Site Admin
Posts: 15711
Joined: Sun May 06, 2007 10:20 am
Location: West Yorkshire

#14

Post by Nick »

Ray P wrote:
Nick wrote:unless it is as simple as tying the outputs of the different chokes together?
Ray
Thats what I assumed you were doing when you said run them in parallel, if the outputs are not connected, then there is no problem.
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: 20157
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#15

Post by Mike H »

I can foresee a possible problem in that the MOSFET's are not perfectly matched. Slight variations in gate Voltage. But might be balanced by each having a following resistor. :?:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Post Reply