This may sound strange to some (or all) of you but I'd like to dim one filament light http://www.urbancottageindustries.c...arge-globe-exposed-filament-lightbulb-40w-60w without using a dimmer. This is because, as far as I understand it, dimmers introduce noise to the electrics. And that affect the sound quality of my stereo. This may sound bonkers to you but take my word for it. I was wondering whether a light switch or a module exists that has several brightness setting. I'd appreciate your advice
How to dim light without using a dimmer
- Thread starter Yukster
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All thyristor clipping control will produce some noise and other methods produce heat.
The question is colour. Using multi lamps one can use more or less lamps but they remain white. If you want red then how red do you want it? Putting lamps in series can reduce the colour temperature as well as light output.
Using a variable transformer would also work. However the one I have is about a 6 inch cube and rated around 100W so would require a rather large box to cool it.
The auto transformer is really the only way not producing massive amount of heat and clearly will not fit in a standard switch back box.
Be be frank although using a transceiver one may need to take special measures to stop interference for a Hi-fi if the EMC rejection is that bad a dimmer effects it then time it went in the bin.
The question is colour. Using multi lamps one can use more or less lamps but they remain white. If you want red then how red do you want it? Putting lamps in series can reduce the colour temperature as well as light output.
Using a variable transformer would also work. However the one I have is about a 6 inch cube and rated around 100W so would require a rather large box to cool it.
The auto transformer is really the only way not producing massive amount of heat and clearly will not fit in a standard switch back box.
Be be frank although using a transceiver one may need to take special measures to stop interference for a Hi-fi if the EMC rejection is that bad a dimmer effects it then time it went in the bin.
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Thanks ericmark. I'll look into the auto transformer solution. Would it be OK to put the veritable transformer in the ceiling cavity?
And as far as the rest of your comment, I can see where you're coming from. But you should listen yourselves, do an A B test and then we can exchange views again. I was a sound engineer in a recording studio for 10 years. Also, I don't believe or go by what I read in magazines but i do know what I'm hearing. Incidentally my dad is an electronics engineer and he was as sceptical as some of you. He could even explain to me why certain cables or noise in the electricity or RF couldn't make a difference to the sound quality, until I ran a demo for him. So as I said, take my word for it or have a listen yourselves. you would need a fairly good system to be able to tell the difference
And as far as the rest of your comment, I can see where you're coming from. But you should listen yourselves, do an A B test and then we can exchange views again. I was a sound engineer in a recording studio for 10 years. Also, I don't believe or go by what I read in magazines but i do know what I'm hearing. Incidentally my dad is an electronics engineer and he was as sceptical as some of you. He could even explain to me why certain cables or noise in the electricity or RF couldn't make a difference to the sound quality, until I ran a demo for him. So as I said, take my word for it or have a listen yourselves. you would need a fairly good system to be able to tell the difference
Simple A/B testing does not prove anything. Unless you are doing carefully crafted double blinds tests where neither you nor the person conducting the test knows which you are listening to at the time, then your brain will make you hear what you want to hear.
As a sound engineer, I assume you know that mixing desks have a DFA control that enables the engineer to get the sound exactly as the producer/talent/etc. wants?
Series connections of two identical lamps is a relatively simple way to dim a pair of lamps. They operate at approx 1/4 power and give a very warm glow.
Quenching the interference from thyristor chopped AC voltage is a black art and where there is a lot of senstive equipment, can be more expensive than the cost of a variable transformer. Beware the variac with an output that goes above the input voltage, so easy to accidentally over volt the lamp.
Chokes or capacitors in series with the lamp can also reduce the current without waste heat being generated. Though the switch off spike from a choke may be detrimental to the filament.
Using a variable controlled current DC source can be effective although some say the use of DC has an adverse effect on the filament. ( ions are said to migrate to the negative end of the filament thus thinning the positive end ). DC would prevent any motor effect that makes the filament vibrate all be it very slightly when AC current is flowing in adjacent turns of a coiled filament.
Quenching the interference from thyristor chopped AC voltage is a black art and where there is a lot of senstive equipment, can be more expensive than the cost of a variable transformer. Beware the variac with an output that goes above the input voltage, so easy to accidentally over volt the lamp.
Chokes or capacitors in series with the lamp can also reduce the current without waste heat being generated. Though the switch off spike from a choke may be detrimental to the filament.
Using a variable controlled current DC source can be effective although some say the use of DC has an adverse effect on the filament. ( ions are said to migrate to the negative end of the filament thus thinning the positive end ). DC would prevent any motor effect that makes the filament vibrate all be it very slightly when AC current is flowing in adjacent turns of a coiled filament.
Not clear from original post whether desire is (a) to just have a dimmed light thus lower voltage gives longer lamp life or (b) whether desire is to be able to change the amount of dimming. Bernardgreen's lamps in series would be a noiseless answer if (a). The pendant/holder arrangement becomes a deciding factor as to practicality.
I'd like to have a single ceiling light dimmed and redish if possible. It looks at its best when dimmed. I'd rather not use a dimmer to avoid noise in the electrics
I agree with you. People hear what they want to hear and I’ve seen it happen many times. As far as my comparisons go, I didn’t run a double blind comparison. I ran blind test for a good few people where a/b a/a and b/b comparisons were made. The listener never knew which one they were comparing so they could have said that one is better than the other when listening to the same setup twice. But they didn’t. That's pretty reliable in my book as far as real world test go
Yes, that's true but...
"Well designed" audio gear will be unaffected by a small amount of power line noise.
Don't forget, your mains will have other peoples "noise" as well as your own.
Frank
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I would agree a simple diode with heat sink would likely dim the lamp.
As to EMC problem with Hi-Fi I remember many years ago having a problem. Cheap record player worked A1 but expensive one had interference and as already said it's a black art. At that time I did not understand transmission lines theory and used coax cable to speakers removing the interference but likely also attenuating certain frequencies.
The major problem with Hi-Fi is the cables. If you set up an aerial then one has to expect it will receive any signals which the length tunes it into. There are ways around the problem I convert audio into RF UHF and send it to remote receivers around the house without a problem.
It is in fact combined with visual so I can watch Sky TV in the bed room but my point is the so called expensive Hi-Fi equipment is renowned for poor rejection in the main due to yards of speaker cable. Run the cable on the floor and often OK tidy the cable up and run it on picture rail and big problem.
I have considered re-wiring my lights. In Europe they had CFL well before we did are countries are hotter and their idea is two circuits one with 1/3 or lights the other with 2/3 of lights giving three levels of lighting with two simple switches. Of course by swapping bulbs you can have a different colour temperature as well as varying light levels. That to me is far better than diodes or auto transformers.
As to EMC problem with Hi-Fi I remember many years ago having a problem. Cheap record player worked A1 but expensive one had interference and as already said it's a black art. At that time I did not understand transmission lines theory and used coax cable to speakers removing the interference but likely also attenuating certain frequencies.
The major problem with Hi-Fi is the cables. If you set up an aerial then one has to expect it will receive any signals which the length tunes it into. There are ways around the problem I convert audio into RF UHF and send it to remote receivers around the house without a problem.
It is in fact combined with visual so I can watch Sky TV in the bed room but my point is the so called expensive Hi-Fi equipment is renowned for poor rejection in the main due to yards of speaker cable. Run the cable on the floor and often OK tidy the cable up and run it on picture rail and big problem.
I have considered re-wiring my lights. In Europe they had CFL well before we did are countries are hotter and their idea is two circuits one with 1/3 or lights the other with 2/3 of lights giving three levels of lighting with two simple switches. Of course by swapping bulbs you can have a different colour temperature as well as varying light levels. That to me is far better than diodes or auto transformers.
But might result in a noticable 50 Hz modulation of the light. A small mains transformer with several input tappings could be used in auto-transformer mode. One with two 120 volt primaries in series across the mains and the lamp across one primary works well. VA rating of the transformer must be at least twice that of the lamp.
With my tongue firmly in my cheek, you could look at something like this http://www.russandrews.com/product....&customer_id=PAA0970017414031SHXLYRRIVQBUGIVC
That is true, but so does virtually all electrical equipment.
If that is true, then it will already be suffering major problems due to interference from CFL and LED lamps, transformers for 12V halogen lamps, washing machines, dishwashers, televisions, set top boxes, microwave ovens, mobile phone chargers, laptop power supplies and every other piece of electronic equipment in your home and in other properties nearby.
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