[sdiy] dare I say - decoupling?

[Magnus Danielson]

From: "Michael Ruberto" <frankentron at hotmail.com>
Subject: Re: [sdiy] dare I say - decoupling?
Date: Sat, 03 Sep 2005 15:07:22 -0400
Message-ID: <BAY107-F15C935D7258E9A843295A8B3A20 at phx.gbl>

Michael,

> >LEDs are fine.
> >Just don't switch the current on and off. Steer it thru the LED or around
> >the LED.
> >Place the transistor for bypassing close to the LED.
> >
> >JH.
> >
> 
> Would it be ok in the feedback loop of an op-amp like in some of the old 
> Oakley stuff?

Doesn't help. The point of Jürgens arrangement is that you locally consume as
much current at any time, regardless of the LED (or LAMP) being on or off.
By doing that, there is a much lower shift in current which needs decoupling.
The benefit is that the same DC current is pulled and there is almost none
shift which needs to be decoupled.

Just tossing it into the feedback loop of an op-amp will not help to acheive
the constant DC-pulling.

Cheers,
Magnus