Power controlers... on another note. - relays

Doug Hughes doug at eng.auburn.edu
Mon Jun 10 06:56:04 PDT 2002

On Tue, 4 Jun 2002, Alvin Starr wrote:

> alvin at Maggie.Linux-Consulting.com wrote:
> > hi ya 
> > 
> > relays are bad .... very bad ....
> > 	- all kinds of mechanical failures
> > 	- all kinds of inductive currents
> > 
> > use an SCR instead .... and it can be turned on and off with
> > a simple +5v circuit on the gate and turned off with a negative
> > pulse ...
> > 	-- same thing as a relay only 10x better ??
> > 
> > c ya
> > alvin
> > 
> > 
> >>all you need is a 5A 110V DC-control relay.  the way this works is 
> >>essentially wire the relay + outlet like so:
> >>it's quite straightforward.
> >>
> >>-josh
> Has anybody played with the X10 controller stuff. I have been thinking
> of that for our computer room but I am not sure if we would have problems.
> The hardware is cheap and readly available and can be easly computer 
> controlled. The prduct line is intended for home use and is not your 
> usual industrial quailty. There is also an upper limit of 255 devices 
> and some possible issues with external interferance.

I did this a few years ago when I used to work at Auburn University.
I still have the page up here: http://www.eng.auburn.edu/~doug/x10.html

I used a CP290 for the main controller and the regular applianace grade
X10 moduled for machines. There are a number of caveats, such as, 
make sure you have your own circuit not shared with somebody else, don't
use wireless, make sure there is plenty of room for differentiation
between one x10 code and another, etc.


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