Unexplained noise heard through speaker when switching closet flourescents off?

[anothaparson]

I have a question regarding a single 15a circuit feeding power and lighting in a small bedroom. The customer wanted a ceiling mounted receptacle in their closet, which I was able to feed out from a receptacle in the room. He mounts a wireless internet unit in the closet and now he has boosted his internet signal giving the excellent quality he was looking for. Great! Job well done

I receive a call to come back and install another receptacle in the attic above the closet which I do and feed off the ceiling mounted outlet. So far everything is great!

I receive a call 2 days later that he is hearing what sounds like a short coming from a speaker recessed in the ceiling outside the bedroom every time he switches his closet lights off.

He plugged in a Mac unit with an amplifier which he connected 2 speakers to. This unit allows him to play music directly from his phone through is speaker wirelessly from anywhere. In this bedroom closet there is installed a T12 2 Lamp fluorescent fixture and whenever the switch for it is turned off it makes a pop which sounds like a short?

The Mac unit works and the speaker are playing music perfectly.

I would appreciate any comments, thoughts, and or opinions on why this is happening.

 

[Rampage_Rick]

Cheap amplifier picking up external noise. I had a similar situation in my last house where every time one bathroom fan was switched off, the speakers on my computer would pop. The switch for the bathroom fan nearest the computer didn't make a sound, but the one further away did. The volume knob on the speakers didn't have an effect on the pop. Those speakers would also pick up the transmissions from newer Liftmaster garage door remotes. Great for checking the batteries in remotes, annoying when the neighbors start replacing their 10 year old openers...

My personal theory on the issue is that the switch is arcing when opened. It's a tiny arc that doesn't last long, but it gives a nice RF pop. Back in the day they used "spark gap transmitters" for Morse code, which transmitted upon a wide range of frequencies. An amplifier with poor shielding or design might pick up any number of these frequencies, and there's your pop.

 

[LEO2854]

I have a question regarding a single 15a circuit feeding power and lighting in a small bedroom. The customer wanted a ceiling mounted receptacle in their closet, which I was able to feed out from a receptacle in the room. He mounts a wireless internet unit in the closet and now he has boosted his internet signal giving the excellent quality he was looking for. Great! Job well done

I receive a call to come back and install another receptacle in the attic above the closet which I do and feed off the ceiling mounted outlet. So far everything is great!

I receive a call 2 days later that he is hearing what sounds like a short coming from a speaker recessed in the ceiling outside the bedroom every time he switches his closet lights off.

He plugged in a Mac unit with an amplifier which he connected 2 speakers to. This unit allows him to play music directly from his phone through is speaker wirelessly from anywhere. In this bedroom closet there is installed a T12 2 Lamp fluorescent fixture and whenever the switch for it is turned off it makes a pop which sounds like a short?

The Mac unit works and the speaker are playing music perfectly.

I would appreciate any comments, thoughts, and or opinions on why this is happening.

Take an AM radio and place it next to any fluorescent fixture and you will hear the interferance from the light they make a lot of noise when they are first turned on and when you shut the off you are breaking the arc in the lamps and that causes Electrical noise as well.

 

[ritelec]

He plugged in a Mac unit with an amplifier which he connected 2 speakers to. This unit allows him to play music directly from his phone through is speaker wirelessly from anywhere. In this bedroom closet there is installed a T12 2 Lamp fluorescent fixture and whenever the switch for it is turned off it makes a pop which sounds like a short?

The Mac unit works and the speaker are playing music perfectly.

Two things........................watch he doesn't blow the speakers. And sounds like a perfect spot for e'ole illegal balanced power conditioner.

 

[don_resqcapt19]

Two things........................watch he doesn't blow the speakers. And sounds like a perfect spot for e'ole illegal balanced power conditioner.

If it is RF from the arc when the switch is operated power conditioners will not eliminate the pop.

 

[Speedskater]

You might thing about putting a snubber capacitor across the switch.

See bottom of page:
http://www.mouser.com/catalog/catalogusd/645/1021.Pdf

 

[ritelec]

SNUBBER CAPACITOR???????

Interesting.

Wonder how it counts in conductor fill ....................

Probably wouldn't count for anything. They only count wire, clamps and devices.

SNUBBER CAPACITOR????????

 

[kwired]

Putting a capacitor across the switch - I can see that might eliminate the interference from the arc when operating the switch, I can also see that making for a big suprise for somebody working on the light and they think the switch in the off position means the light is dead.

 

[ritelec]

I can also see that making for a big suprise for somebody working on the light and they think the switch in the off position means the light is dead.

OUCH! Bit by the SNUBBER.................

 

[kwired]

OUCH! Bit by the SNUBBER.................

That word seems to tickle you doesn't it?


SNUBBER....SNUBBER....SNUBBER

 

[ritelec]

That word seems to tickle you doesn't it?


SNUBBER....SNUBBER....SNUBBER

Yes............it's too funny....................

I can't tell if it should be said with a pirate voice,

Or now the way you just wrote it............as more of an effect..... like a limp with one foot dragging.................:rotflmao:




(no offense to anyone here who has a limp and drags their foot) ......:rotflmao:

 

[anothaparson]

My better judgement is telling me that I should just move my receptacle and relocate his amplifier and wireless Mac unit further away from light.

Thanks to those who have taken a minute to comment and add some insight. I appreciate all your experiences and thoughts!

 

[ELA]

"Snubbers" are often used in the form of a series Resistor and Capacitor. This combination can be placed across the load rather than across the switch to eliminate the concerns about leakage current when the switch is in the off position.

A magnetic ballast generates a large transient when switched off abruptly. The RC network reduces the transient generation at the point of generation.