dcs60222@zach.fit.edu ( ENRIQUEZ) (10/10/89)
Hello,
Several months ago I posted a problem I had with a transformer
driving 25 12v, 20w lights. The problem was that the transformer could not
drive the lights past the 12th to 14th light without dimming the whole
chain. I asked for help...
And I recieved it! Many thanks to all who responded to my inqury.
The basic consensus was that IF I could match the transformers identically
and IF the wire was low enough gauge I MIGHT be able to do it. (Some
others said to buy a larger transformer)
Well, I conveyed the results to my "clients" (i.e. parents) and they
were overjoyed, estatic, etc. So, they gave the printout to the
"lighting designer" and she promptly threw it away, saying all that was
needed to be done was to move the transformer closer to the lights (
there was ~40 feet of 12 gauge wire).
They did it, and it improved, but still not good enough...
So, now an P.E. has been hired by them (Dad's a M.D.) and his soulution
is to buy an identical transformer, put it in the old place (~40 feet away
from the lights) and put the old transformer next to the lights.
QUESTION: assuming a lenght of 35 feet of 12-gauge wire between two
750 watt transformers, will the house burn down or the
transformers blow up first <grin>. Or, by heaven's grace
WILL THIS WORK???
Thanks in advance ....
Mark Enriquez dcs60222@zach.uucp kleemann@vms.macc.wisc.edu (Brad Kleemann) (10/10/89)
In article <616@winnie.fit.edu>, dcs60222@zach.fit.edu ( ENRIQUEZ) writes... { Stuf deltd } > > QUESTION: assuming a lenght of 35 feet of 12-gauge wire between two > 750 watt transformers, will the house burn down or the > transformers blow up first <grin>. Or, by heaven's grace > WILL THIS WORK??? > Depends on wheter the transformers are in phase or not. --Brad > Thanks in advance .... > > Mark Enriquez dcs60222@zach.uucp
ankleand@mit-caf.MIT.EDU (Andrew Karanicolas) (10/12/89)
In article <616@winnie.fit.edu> dcs60222@zach.UUCP ( ENRIQUEZ) writes: >Hello, >chain. I asked for help... > > And I recieved it! Many thanks to all who responded to my inqury...... >others said to buy a larger transformer) I was one of those people, and I still think that a larger transformer would be easier. > > Well, I conveyed the results to my "clients" (i.e. parents) and they >were overjoyed, estatic, etc. So, they gave the printout to the >"lighting designer" and she promptly threw it away, saying all that was >needed to be done was to move the transformer closer to the lights ( >there was ~40 feet of 12 gauge wire). I thought it was made clear that the original transformer did NOT have enough volt-ampere capacity. > So, now an P.E. has been hired by them (Dad's a M.D.) and his soulution >is to buy an identical transformer, put it in the old place (~40 feet away >from the lights) and put the old transformer next to the lights. Good grief! They could have easly purchased a larger tranformer before hiring a P.E. > > QUESTION: assuming a lenght of 35 feet of 12-gauge wire between two > 750 watt transformers, will the house burn down or the > transformers blow up first <grin>. Or, by heaven's grace > WILL THIS WORK??? I don't know, ask heaven :-) You know, there are problems in this world that are very easy to solve, your parents lighting problem is one of them. Good luck. > Thanks in advance .... > > Mark Enriquez dcs60222@zach.uucp -- =================================================================== Andrew Karanicolas MIT Microsystems Laboratory ankleand@caf.mit.edu MIT EECS Cambridge, MA 02139 ===================================================================
dcs60222@zach.fit.edu ( ENRIQUEZ) (10/12/89)
In article <3297@mit-caf.MIT.EDU> ankleand@mit-caf.UUCP (Andrew Karanicolas) writes: > >You know, there are problems in this world that are very easy to solve, >your parents lighting problem is one of them. Good luck. > Hey, excuse me for asking... Again, thanks for you suggestion of getting a larger transformer. It was of use. However, what does this post prove? That some people "easy" problems are not so easy for others? I don't understand why you wasted your time telling me how easy it is to solve, while not giving a simple solution yourself. My understanding of the net is to increase understanding of topics which you might be interested in, and to help others which might not have the same understanding you do (if YOU want to, else ignore). Mark E. dcs60222@zach.uucp
ankleand@mit-caf.MIT.EDU (Andrew Karanicolas) (10/13/89)
In article <631@winnie.fit.edu> dcs60222@zach.UUCP ( ENRIQUEZ) writes: >In article <3297@mit-caf.MIT.EDU> ankleand@mit-caf.UUCP (Andrew Karanicolas) writes: >> >>You know, there are problems in this world that are very easy to solve, >>your parents lighting problem is one of them. Good luck. >> > >Hey, excuse me for asking... > >Again, thanks for you suggestion of getting a larger transformer. >It was of use. > >However, what does this post prove? That some people "easy" problems >are not so easy for others? I don't understand why you wasted your time >telling me how easy it is to solve, while not giving a simple solution >yourself. > I tried to give the simplest solution I could think of. >My understanding of the net is to increase understanding of topics which >you might be interested in, and to help others which might not have the same >understanding you do (if YOU want to, else ignore). > > Mark E. dcs60222@zach.uucp The problem you have seems to be coming down to an issue of cost vs. safety. The reason I said the solution to the problem was easy was because the use of a single large transformer will do the job. It is unfortunate that such a transformer is a costly item; if I recall, the focus of the problem originally was how to avoid this cost. What triggered my reaction to your last posting was the comment about relying on "heaven" that nothing goes wrong. I'm sure that there was jest in this. However, for electrical wiring that uses AC mains, you should be fairly serious about what you are doing. There have been other people on sci.electronics talking about how they deal with AC mains and I did not agree with their methods regarding safety and practicality in home (or other) environments; this is my opinion. What is the rating of each of the transformers proposed earlier? 750W each or is 750W the total rating. -- =================================================================== Andrew Karanicolas MIT Microsystems Laboratory ankleand@caf.mit.edu MIT EECS Cambridge, MA 02139 ===================================================================
dcs60222@zach.fit.edu ( ENRIQUEZ) (10/13/89)
In article <3303@mit-caf.MIT.EDU> ankleand@mit-caf.UUCP (Andrew Karanicolas) writes: >The problem you have seems to be coming down to an issue of cost vs. >safety. The reason I said the solution to the problem was easy was >because the use of a single large transformer will do the job. It >is unfortunate that such a transformer is a costly item; if I recall, >the focus of the problem originally was how to avoid this cost. Yes, that was the focus of the original problem. It seemed to me to be a waste to have to junk the smaller transformer to buy a larger one. Since I don't know how to resell this type of thing, I was hoping to save a few $$ AND learn a little about basic transformer operation. >What triggered my reaction to your last posting was the >comment about relying on "heaven" that nothing goes wrong. I'm sure >that there was jest in this. However, for electrical wiring that uses >AC mains, you should be fairly serious about what you are doing. Agreed! It was in jest, and I probably should not have been so flippent in my remarks. You know, this problem IS trivial, and I probably should not have wasted net bandwidth posting it. I have since talked to professors here at school and have recieved good information (and references). >There have been other people on sci.electronics talking about how they >deal with AC mains and I did not agree with their methods regarding >safety and practicality in home (or other) environments; this is my opinion. > >What is the rating of each of the transformers proposed earlier? >750W each or is 750W the total rating. >-- > =================================================================== > Andrew Karanicolas MIT Microsystems Laboratory > ankleand@caf.mit.edu MIT EECS Cambridge, MA 02139 > =================================================================== To better define the problem, they are rated at 750w each. Since there are 25 20w bulbs, the transformer SHOULD drive the lamps. This is why we moved the transformer closer, thinking path resistance might be stealing wattage. My real question now is: Can 12-gauge wire handle that type of current? Again, thanks... mark enriquez dcs60222@zach.uucp