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Forum Index : Electronics : Ripple-switch filter?
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Does anyone know how you would go about filtering off the signal the power board sends down the mains to switch the hot-water cylinder off and on? Here in NZ, it is about 1kHz by the sound of it, but it is a perfect frequency for getting into audio paths. My amplifier is always whining with intermittent ripple-switch tone bursts, as they manage the load on the network. Is anyone aware of anything you can get/make/buy that will filter this out of the MAINS VOLTAGE, cos it is passing right through all transformers and PSU's, and ends up as a very annoying whirr noise on the stereo. One way around that is to crank up the volume, but if you want the music quiet as background music, and that bloody ripple-switch noise keeps coming over the speakers - roughly 1kHz is not much fun as background music...... Smoke makes things work. When the smoke gets out, it stops! |
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Madness Guru  Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
Have you considering making a complaint to the power company as they are the one causing it. You also could build an Inverter and have your own clean power source  There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
LOL  - Love your comment about the inverter - funny you should say that......
Complaining to the power board would get me no-where. As every single house has a ripple-switch, they would just say it is your hard-cheese cos they ain't gonna change anything for one or two complaints about the ripple-switch noise. I suppose I could ask them about it, but I seriously doubt they would do anything to help there. Smoke makes things work. When the smoke gets out, it stops! |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
If they won't turn down the strength of it or supply a filter to stop they should at least provide you with details of what would stop it. Have you tried running the amplifier through a small computer UPS? There are only 10 types of people in the world: those who understand binary, and those who don't. |
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yahoo2 Guru Joined: 05/04/2011 Location: AustraliaPosts: 1166 |
http://www.elec.uow.edu.au/apqrc/content/technotes/UOW019_Tech%20Note%2014_AW_screen.pdf it says the ripple can be as high as 30 volt with a combination of underground and poles and wires causing amplification. interesting I'm confused, no wait... maybe I'm not... |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 6101 |
They are called "zellweger relays" and a google search will give plenty of info about them but not a lot in ways to filter it out. Back in my early days, the signals were generated by motor-generator sets. Even then you could hear the 1050Hz signals if you were standing near the meter box when they went off. They are used in most Australian states with a notable exception of Tasmania. We like to be different and switch our off-peak loads using time switches. A bit sad if the peak load period changes! Jim VK7JH MMedit MMBasic Help |
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| Phil23 Guru Joined: 27/03/2016 Location: AustraliaPosts: 1664 |
Hey Grog, Just curious about how much current your audio system draws? Don't suppose you can beg borrow or steal a 12V PSW inverter & they running it of that to see what happens? Would need a fairly juicy 12V supply though, & maybe something like a SLA battery to buffer the peaks. Might isolate whether it's getting in via the P/Supply or induced some other way. Phil |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9308 |
Well, Phil, the new one is currently under construction and uses +/- 32v AC supply, with 8.4A of capacity per rail - a 16A toroid from Germany is running the power amps side of things. A good 50% or more of that capacity will be used by the sub amps I would expect - they are the ones that suck most of the juice. I am in the process of building one of those OzInverter beasts as described in the Electronics forum. So among other things, once that is up and running, I can chop off the street supply. Smoke makes things work. When the smoke gets out, it stops! |
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