#1
Hi guys,

you know how dimmer switches create an unwanted hum which is picked up the guitar/amp. If you turn the lights all the way up the hum reduces but is still there. Does anyone know the result of fitting a simple on/off switch in parallel with the dimmer so you can turn the dimmer off and flip the on/off switch to light the room?

Any ideas.
#2
my suggestion: buy a lamp and plug it in an outlet that isnt connected to the dimmer switch.
or play in the dark, its more fun.
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#4
wont it be easier to shield your guitr and amp from the hum
also if you want it to turn off wouldnt it be in series with the switch?
#5
just move rooms?
Belief is a beautiful armour but makes for the heaviest sword.
#6
I'm currently doing the tabletop lamp thing but dont have much desk space.
I'm not changing the lights just simply adding a switch, it's a 5 minute job. Sheilding helps but thats more for blocking the stactic from me whilst playing isn't it? I'm all sheilded up but it's no match for a dimmer hum.

If the switch was in series then the dimmer would no longer work. when the on/off switch is off the dimmer wouldn't recieve any current and if the on/off switch was on well then it might as well not be there and the dimmer would operate as it does now. It would have to be in parallel.
#8
^sal that is a very stupid thing to say.

a dimmer switch uses a triac to switch the ac waveform off for certain durations of the cycle. the downside to triacs is that you cant turn them fully on or off. dimmers are SUPPOSED to have inductors in there to filter out electrical noise. They usually do a satisfactory job of it.

you'll have to put a switch in paralell to the dimmer control to "short" it. basically like a bypass switch. putting a switch in series does nothing but turn the lights on and off. the dimmer will still work just as normal with the switch closed.

i dont know if you need to be attempting anything involving house wiring. get someone experienced to do it for you.
#9
Quote by Invader Jim
^sal that is a very stupid thing to say.

a dimmer switch uses a triac to switch the ac waveform off for certain durations of the cycle. the downside to triacs is that you cant turn them fully on or off. dimmers are SUPPOSED to have inductors in there to filter out electrical noise. They usually do a satisfactory job of it.

you'll have to put a switch in paralell to the dimmer control to "short" it. basically like a bypass switch. putting a switch in series does nothing but turn the lights on and off. the dimmer will still work just as normal with the switch closed.

i dont know if you need to be attempting anything involving house wiring. get someone experienced to do it for you.

Sorry

In his last post he had all statements and no questions, so i thought he had it all figured out.
#10
we have no idea of knowing how experienced TS is. its a bad idea to tell someone to go do something they may not be experienced enough to do, especially if it can hurt or kill them.

its better to under-estimate experience than over-estimate.
#11
I'm no elecrician, but it's only a switch in parrelle with another switch.

It's intresting you mentioned inductors, maybe if i buy a more expencive dimmer it may have inductors and just better all round quality.

But still in theory the on/off switch would work wouldn't it. Just a small rocker (suitable for 240v) fitted next to the dimmer knob.
#12
all dimmer switches have filter inductors. if they didnt, nobody would buy them. yours may just be a lower quality dimmer with inadequate filtering.

it should work. idk about UK house currents, but in US the rocker would have to be rated at 15 amps (I assume you are in UK because you said 240v).

i think all the house currents over there are half of ours since the voltage is twice as high. current and voltage are indirectly related.

since it seems you are going at this yourself, if you can find one just go with a 15A switch. It'd prolly be better to get a real residential light switch. then you know you are meeting the current requirement.

and remember to turn off the power for the room at the breaker panel. 240v is alot more dangerous than 120v.

a single pole dimmer has 2 hots and a ground. simply wire the new switch across the 2 hot wires. if your dimmer isnt a single pole, make sure you follow the connection diagram of the dimmer and know where to put the new switch.
#13
Thanks for the advice,

i like the idea of using a residential light switch.

I will of couse isolate the upstairs lighting ring and measure across the terminals on the switch to check it's all clear berfore i start.

I'm not sure about the current but can't i work it out isn't it I=P/V. so thats 60 watts divided by 240v. Thats 0.25 Amps. Actually there's 3 bulbs so 180/240 = 0.75A. The switch i was gonna use says 240v 4A on it so if the above calculation is correct it should work.

Or i'm just embarrasing myself here and getting it all wrong.
#14
count the number of lights that the dimmer controls and add their currents together.

you are right, I=P/V. but maybe one day someone will install a light higher than 60W. 75W would be a good number, 100W would be better, but all this uncertainty is why I said use a switch rated the same current as the breaker for that branch circuit.

In the US, branch circuits with lights only are rated no less than 15A. If there is even a single receptacle on that branch circuit, it must be rated no less than 20A. since this is a dimmer, it wont be connected to a receptacle circuit so over here we'd be safe with a 15A switch.

just go to the breaker panel, find the breaker that controls the room with the dimmer, and write down what the current rating for the breaker is. it should say right on the toggle.

this is becoming alot of trouble just to get rid of a little noise...

if you use a real residential light switch (you should) then all of this can be avoided and you can go straight to wiring. see what kind of dimmer you have. if it is a single pole, do like my last post said. if it has more than 2 hots and a ground, it is not a single pole dimmer. in that case, you'll need what electricians call an S2 light switch. it is a DPST switch. a regular light switch (called an S1 switch) is SPST.