[GreenKeys] Loop power supplies

[drlegendre .]

IOW it's not a constant-current supply, but rather a high voltage (~300V)
current-adjustable supply. Ultimately, its behavior isn't much different
than that of a simple passive rheostat - nor am I exactly sure what
advantage it provides over the former.

A pair of series-connected rheostats (one coarse, one fine) would seem to
exhibit roughly the same behavior - a high terminal voltage purveying a
fixed, adjustable current.

On Sun, Mar 4, 2018 at 4:54 PM, Jeffrey Angus <jdangus at att.net> wrote:

> On 3/4/18 3:51 PM, Nick England wrote:
>
>> I didn't really look at it. The text calls it a current regulator and
>> does say "They have been designed to provide a steep wave
>> front when keyed to promote more positive action of relay or
>> magnet operated equipment."
>>
> That's the key. It's a current regulator, not a current source.
>
> By using a vacuum tube in place of a fixed resistance, it will
> provide a somewhat faster rise time.
>
> But unlike a true current source, it will not provide a fixed value
> of current for any and all loads. It has to be adjusted each time
> for a specific load.
>
>
>
>
> --
> "I am a river to my people."
> Jeff-1.0
> WA6FWI
> www.foxsmercantile.com
>
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