Dichroic Lights & Toroidal TF's

S

Scott Hill

Guest
Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.

Also, how much stress would it place on the 150VA TF to only drive one, say
20W bulb.
thanks
any advice would be greatly appreciated!
cheers
scott :)

scottnet@ntlworld.com
 
in article 9mBqb.1934$us.967@newsfep3-gui.server.ntli.net, Scott Hill at
scottnet@ntlworld.com wrote on 11/6/03 4:06 PM:

Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.

Also, how much stress would it place on the 150VA TF to only drive one, say
20W bulb.
thanks
any advice would be greatly appreciated!
cheers
scott :)

scottnet@ntlworld.com


This seems like a strange question to me.
Click to expand...

First, I do not know what you mean by dichroic lights. Do you literally mean
two colors? In one light? How are these lights constructed and how do they
work? It seems to me that if you specify what is required to make the lights
work, you would not have to specify the transformers. Just provide what the
lights need in any way you can.

Bill
 
In article <BBD039F9.37A5%salmonfry@sbcglobal.net>,
Repeating Decimal <salmonfry@sbcglobal.net> writes:
This seems like a strange question to me.

First, I do not know what you mean by dichroic lights.
Click to expand...
12V halogen reflector lamps -- reflectors are usually dichroic,
reflecting visible light but allowing infra-red to pass straight
through so the beam doesn't contain so much heat, but the fitting
has to cope with the heat being dumped into it instead.

--
Andrew Gabriel
 
In article <9mBqb.1934$us.967@newsfep3-gui.server.ntli.net>,
scottnet@ntlworld.com mentioned...
Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.

Also, how much stress would it place on the 150VA TF to only drive one, say
20W bulb.
Click to expand...
Don't worry about that, be concerned if you use a 150W transformer for
three 50W lights. Loading the transformer to its full rated capacity
is going to cause it to get hot, which will shorten its life. Use a
200W 0or more transformer so that it will not be running at its
maximum.

thanks
any advice would be greatly appreciated!
cheers
scott :)

scottnet@ntlworld.com
Click to expand...
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"Scott Hill" <scottnet@ntlworld.com> wrote in message
news:9mBqb.1934$us.967@newsfep3-gui.server.ntli.net...
Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get
a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.
Click to expand...
You got it in one. Regulation, 12V lamp is rated to 12V +/- 5% . Too much
and lamp life goes down the pan, too little and brightness and colour are
wrong.

how much stress would it place on the 150VA TF to only drive one, say
20W bulb.
Click to expand...
No stress on the transfomer, lot of stess on the lamp.

If its a wire or rail system use wound transformers, if it`s individual
lights use electronic transformers, RFI is to graet to use these on long
conductor schemes.

Adam

thanks
any advice would be greatly appreciated!
cheers
scott :)

scottnet@ntlworld.com
Click to expand...
 
Thanks guys!
and i didnt know dichoric meant 2-colours!
but the IR comment was correct

cheers
soctt :)


"Scott Hill" <scottnet@ntlworld.com> wrote in message
news:9mBqb.1934$us.967@newsfep3-gui.server.ntli.net...
Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get
a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.

Also, how much stress would it place on the 150VA TF to only drive one,
say
20W bulb.
thanks
any advice would be greatly appreciated!
cheers
scott :)

scottnet@ntlworld.com
Click to expand...
 
"Scott Hill" <scottnet@ntlworld.com> wrote in message
news:9mBqb.1934$us.967@newsfep3-gui.server.ntli.net...
Hey all!
i'd like to know what the differences are between specific toroidal
transformers for dichroic lights, and just any old toroid.
I want to drive a rail of 3 dichroic lights (upto 50W ea.) so im gonna get
a
150VA TF, but would the regulation of said "any-old" TF be so poor as to
blow all the lamps if one failed?
im not planning on dimming etc.

Also, how much stress would it place on the 150VA TF to only drive one,
say
20W bulb.
thanks
any advice would be greatly appreciated!
Click to expand...
Two main areas that may be of concern:
1. regulation - these lamps are very supply sensitive (eg see GE website
for data) and are designed to run within +/- 5% (max) of nominal to get
decent life and output performance.

2. Safety - remember this must be SELV et al. Are you sure your
transformer is up to it.
 
In message <BBD039F9.37A5%salmonfry@sbcglobal.net>, Repeating Decimal
<salmonfry@sbcglobal.net> writes
This seems like a strange question to me.

First, I do not know what you mean by dichroic lights. Do you literally mean
two colors? In one light? How are these lights constructed and how do they
work? It seems to me that if you specify what is required to make the lights
work, you would not have to specify the transformers. Just provide what the
lights need in any way you can.
Click to expand...
Dichroic's or "dichroic lights" are terms used to describe the generic
MR16 (and others) type of lamps that use a dichroic glass reflector to
project visible light forwards but pass the infra red component back
through the rear of the lamp.

The question regarding the use of a single 50W lamp on a 150VA
transformer is perfectly valid, since the low load will lead to a higher
voltage due to the regulation of the transformer.

With torroidal transformers the regulation % tends to be quite low which
is good, but if the voltage measured at the lamp is measured and found
to be too high, a cheat is to maybe use a slightly longer cable to
introduce a bit of voltage drop between the transformer and lamp. If
the voltage supplied to the lamp is lower than 12V then the light output
will reduce quite significantly while the lamp life will also increase
significantly. A good compromise between lamp intensity and life is
11.5V

--
Clive Mitchell
http://www.bigclive.com
 
On Fri, 7 Nov 2003 18:45:25 -0000, "R.Lewis" <h.lewis-not this
bit-@connect-2.co.uk> wrote:

Two main areas that may be of concern:
1. regulation - these lamps are very supply sensitive (eg see GE website
for data) and are designed to run within +/- 5% (max) of nominal to get
decent life and output performance.
Click to expand...
I do not believe these lamps are substantially more sensitive to
voltage variation (on a percent basis) than any other incandescent
lamp. The problem is that with a low voltage system it is much more
likely that the voltage at the lamp terminals will be a bit too high
or too low.

--
Vic Roberts
http://www.RobertsResearchInc.com
 
in article $ypTwtDb$Br$Ewpg@emanator.demon.co.uk, Clive Mitchell at
clive@emanator.demon.co.uk wrote on 11/7/03 2:42 PM:

In message <BBD039F9.37A5%salmonfry@sbcglobal.net>, Repeating Decimal
salmonfry@sbcglobal.net> writes
This seems like a strange question to me.

First, I do not know what you mean by dichroic lights. Do you literally mean
two colors? In one light? How are these lights constructed and how do they
work? It seems to me that if you specify what is required to make the lights
work, you would not have to specify the transformers. Just provide what the
lights need in any way you can.

Dichroic's or "dichroic lights" are terms used to describe the generic
MR16 (and others) type of lamps that use a dichroic glass reflector to
project visible light forwards but pass the infra red component back
through the rear of the lamp.
Click to expand...
As this thread developed, I began to realize that dichroic really meant
dicrhroic in the sense that there were filters present thar reflected and
transmited unlike colors. The complication is that dichroism has little to
do with the generation of light but much to do with heat transfer and
effective color temperature. To keep things simple, the dichroism should
have been kept separate from electrical characteristics.

Bill
 
In article <BBD2BED4.391D%salmonfry@sbcglobal.net>, Repeating Decimal
<salmonfry@sbcglobal.net> writes
in article $ypTwtDb$Br$Ewpg@emanator.demon.co.uk, Clive Mitchell at
clive@emanator.demon.co.uk wrote on 11/7/03 2:42 PM:

In message <BBD039F9.37A5%salmonfry@sbcglobal.net>, Repeating Decimal
salmonfry@sbcglobal.net> writes
This seems like a strange question to me.

First, I do not know what you mean by dichroic lights. Do you literally mean
two colors? In one light? How are these lights constructed and how do they
work? It seems to me that if you specify what is required to make the lights
work, you would not have to specify the transformers. Just provide what the
lights need in any way you can.

Dichroic's or "dichroic lights" are terms used to describe the generic
MR16 (and others) type of lamps that use a dichroic glass reflector to
project visible light forwards but pass the infra red component back
through the rear of the lamp.

As this thread developed, I began to realize that dichroic really meant
dicrhroic in the sense that there were filters present thar reflected and
transmited unlike colors. The complication is that dichroism has little to
do with the generation of light but much to do with heat transfer and
effective color temperature. To keep things simple, the dichroism should
have been kept separate from electrical characteristics.

Bill

We are really talking about low voltage lighting and possibly lighting
Click to expand...
within a ceiling .
I am in favour of torroidal transformers rather than electronic
transformers.
There are now torroid transformers that fit into the hole made for the
lights, one torroid/light .
I did the wrong thing! fitted 150W electronic transformers to drive 5
20W 12 V "dichroics"
The volts drop from transformer to furthest light even with "correct"
wiring is significant and more important, the em radiation in the medium
wave and long wave blot out all radios in the room.
The electronic transformers dissipate 20% or so of the energy so they
warm up and overheat in a confined space.
Don't place them near any of the lights as the extra heating from the
lights exacerbate the problem.

--
ddwyer
 
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