Need a device that GENERATES AC mains noise

[Alex from Oz]

I'm tired of explaining to people that AC mains power effects audio gear.
So, what I want is a very cheap, effective device that I can buy/build that creates masses of audible hum, buzzing and noise when plugged into a mains power outlet near some audio gear.
Basically, I want to be able to say 'Here, plug this in next to your audio system and then tell me AC power has no effect...'

Any ideas?

Cheers,

Alex

[Pjotr]

Buy a cheap electric welder….

Fiddling with the mains this way is for safety reasons beyond the scope of this forum IMHO. Anyway, professional gear (programmable AC supplies) to do this is in the price area of 10K – 20K. Maybe you can find something on Ebay?

[Alex from Oz]

Thanks, but a welder isn't practical and a programmable AC power supply is way out of scope budget wise.
Most electrical projects on diyaudio use mains power - so what I'm asking for presents no greater safety issues than any other project that uses AC mains.
What I was hoping for is some kind of plug-in oscillating circuit that feeds noise into the mains power outlet which can be heard through audio gear.
Essentially the exact opposite of what we normally try to achieve!

Cheers,

Alex

[Ron E]

Dimmer?

[wwenze]

Originally Posted by Ron E

Dimmer?

Was thinking of something that can include it... and them some...

fluorescent lamp

Plus parallel enough of them and you might get enough surge to kill something.

[Alex from Oz]

Dimmer would be about the right size. I could fit one into a metal box.
What would be the best to use as a load for the dimmer - wire wound resistor maybe?

Cheers,

Alex

[marce]

Hi Alex,
in a past life I worked for a firm that designed Gen Set controllers, due to the horrible mains around the world and trouble determining where the zero crossing was, we designed a dirty mains simulator for testing circuitry. Basicly we had a signal gernerator with the fundimental frequency + lots of nasty harmonics, this wired up a chip amp, the output of this put through a transformer to give us our mains voltage. Of course to get some current it is quite a large rig.
This was also used to test PSU's as it is during the inital stages of a PSU that you want to filter out this crud on the mains, if it gets through to the equipment you are asking for problems.

[Geek]

CFL bulb does wonders too at making power line noise from 60Hz to > 30MHz for under $5

Cheers!

[markr14850]

Try an adjustable soldering iron with the power set at 2/3.

Also try a string or two of LED (not incandescent) Christmas tree lights.

[wwenze]

Can't fit many fluorescent lamps inside into a metal box though, even if they're CFL. What produces the noise anyway, the power supply? Would it be possible to build one specially designed for producing noise?

I wonder if it's possible to make the earth noisy too.