Why do we use so many transformers in our roof
Halogen July 31st, 2006Hi Daniel
I was told that there are transformers that can run more than one 12 volt quartz halogen lamp connected to them. If so can you please advise why do we normally use one transformer per downlight. I was considering installing 3 down lights in the kitchen area of my home to run off one transformer and was wondering the pros and cons of using one 12 volt low voltage transformer would be.
Thanks
Bill
July 31st, 2006 at 9:09 am
1. Hi Bill
What great question! I often ask myself the same question but my electrician came up with a few good answers which I am happy to share with you.
The first one is cost. Like anything in the world the more something is produced of any item, normally the cheaper it is. So standard 50 watt or 60 watt transformers, as they are mass produced, are cheaper than larger ones.
Another problem when using a single transformer will be access as it could make it difficult to change after a failure has occurred. When you use a single transformer it is easy to get to as you can easily pull the transformer back through the hole to replace.
The other reason is of course when a single large transformer fails it will leave you in complete darkness as all 3 lights will fail at once.
Another reason to use one transformer is to keep the power source close to the lamp.
You may find significant voltage loss when you run cable over any length. As you are only talking about 12 volts to start with, any percentage loss will greatly reduce the light output. On the upside though, you may find that the lamp life may be extended as the lamps would be consistently run under voltage.
For me in my home, I have a transformer for each downlight.
So the choice is yours.
Daniel Purser
Lighting Expert
Lighting Pro Australia
daniel@lightingpro.com.au