[time-nuts] Regulator choices

[Jim Lux]

On 6/30/13 7:43 AM, Charles P. Steinmetz wrote:
> A three-terminal regulator (3TR) comprises (i) a voltage reference, (ii)
> an error amp, and (iii) a current amplifier.  There is no need to
> duplicate the voltage reference or the error amp just because you need
> more current.  In fact, they can only lead to problems with current
> sharing and/or oscillation.  If the need is simply more current, add an
> external pass device.  It may not be quite as easy as piling on more
> 3TRs (i.e., it takes a little thought), but at the several-ampere level
> it will almost certainly be cheaper.  In many cases, the design is
> already done -- there are hundreds, if not thousands, of example
> circuits in manufacturers' app notes, which are easily found on the Web.
>

Unless you're looking for high efficiency or low dropout, an easy way is 
to use a 3 terminal (like LM317) driving an emitter follower of 
appropriate rating (finally, something to use those old 2n3055s you have 
laying around).


If you're looking for high efficiency, you might look at the Cui 78V00 
series.  They're DC/DC switchers in 3 terminal configuration with a 
variety of current ratings.