Control the amplitude of a 115VAC

hey, thanks, less components idea. It is easier
to turn on and off that the variac.

Regards,

Carlos A. Estrada

----- Original Message ----
From: Don Pomplun
To: p...
Sent: Friday, September 19, 2008 7:05:42 PM
Subject: Re: [piclist] Re: Control the amplitude of a 115VAC
If saving energy is the goal, reducing the
voltage on incandescent bulbs is a poor choice. The quality of the
light diminishes much more quickly than the energy used. You'd do
better to have MANY full brightness lights of low wattage, and
selectively switch off groups. That way the color would remain the
same, even as brightness decreases. Of course, it's stepwise, not
continuous (unless you have a really big bunch of bulbs). Could be
done, though.

At 04:57 PM 9/19/2008, you wrote:
John,

Thanks, good idea. The thing is I want to control some
public lights with your Variac idea in order to save some
KW. But using thyristors and similar is noisy.

Thanks,

Carlos A. Estrada

----- Original Message ----
From: jmsmith871
To: piclist@yahoogroups .com
Sent: Friday, September 19, 2008 7:45:36 AM
Subject: [piclist] Re: Control the amplitude of a 115VAC

Dear, ... (what is your name?)

My experience with electronic control of high power is practically
nil. Richard mentioned the possibility of using a Variac, and
controlling it with a servo. That should work. I sometimes use a
Variac, manually controlled, in various experiments around the
shop.

You didn't mention how quickly the amplitude would need to change
in
response to a digital control signal. A servo-controlled Variac
might
take up to a second, or so, to change the amplitude. Less for small
changes.

That exhausts my knowledge on this subject. Good luck in your
quest.

Best regards,
John

--- In piclist@yahoogroups
.com, Global Positioning
wrote:
> John,
>
> Thanks. Yes, I know about dimming but, I do not want to use
> the typical dimmers that PWM chopping the wave in order to
> control the power. Instead, I want to control the amplitude
> ...
>
> 115VAC @1A is just enough right now but I think I would
> need up to 277VAC and some 7 amps.
>
> It is ok a few settings for amplitude, while variability would
be
> the best.
>
> Quasi-sinusoidal is enough...
>
> Ideas?
>
> Thanks, Start a New Thread

--- In p..., Global Positioning
wrote:
> hey, thanks, less components idea. It is easier
> to turn on and off that the variac.
>
> Regards,
>
> Carlos A. Estrada

But it's the answer to a completely different question.

Richard

Start a New Thread

Team,

I wonder if "Saturable Reactor Core" based Servo System could be used for this purpose ?

It might cost fortune for a new design but one can find suitable unit in military surplus maybe ?

"The saturable reactor regulator controls output voltage by varying the impedance of the saturable reactor winding in series with a step-up autotransformer"

There is no moving parts, it can handle many kilowatts.

For example please see http://www.rge.com/MediaLibrary/2/5/Content%20Management/Shared/UsageAndSafety/PDFs%20and%20Docs/CI%20Power%20Quality%20Brochure.pdf

Best regards

Matt
----- Original Message -----
From: jmsmith871
To: p...
Sent: Friday, September 19, 2008 8:45 AM
Subject: [piclist] Re: Control the amplitude of a 115VAC
Dear, ... (what is your name?)

My experience with electronic control of high power is practically
nil. Richard mentioned the possibility of using a Variac, and
controlling it with a servo. That should work. I sometimes use a
Variac, manually controlled, in various experiments around the shop.

You didn't mention how quickly the amplitude would need to change in
response to a digital control signal. A servo-controlled Variac might
take up to a second, or so, to change the amplitude. Less for small
changes.

That exhausts my knowledge on this subject. Good luck in your quest.

Best regards,
John

--- In p..., Global Positioning
wrote:
>
>
> John,
>
> Thanks. Yes, I know about dimming but, I do not want to use
> the typical dimmers that PWM chopping the wave in order to
> control the power. Instead, I want to control the amplitude
> ...
>
> 115VAC @1A is just enough right now but I think I would
> need up to 277VAC and some 7 amps.
>
> It is ok a few settings for amplitude, while variability would be
> the best.
>
> Quasi-sinusoidal is enough...
>
> Ideas?
>
> Thanks, Start a New Thread