Electrical circuit noise filters?

Drifter said:
Was going to say the exact same thing. Could be a potential fire hazard as well.
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Well there's no shortage of earth AFAIK, just devices that actually use it. Only my TV uses it on that circuit with:
TV, Hifi, DSTV decoder, Raspberry Pi, 4x2 HDMI switch, Wii U, Wireless Router.
I'll get the multimeter out and check earth continuity later.
 
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bekdik said:
check that live & neutral wires are connected the right way around
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With earthed plugs - for sure. For everything else... no way to do it properly. I had read an article some time ago about line noise being an issue if you have L / N the wrong way around on a 2 pin device. Not sure if legit.
 
So the older decoders with PSUs built into them, ( not the newer versions using external PSUs) have only a live and a neutral connection. With these units in theory, one could simply plug em in and not worry about which way around the 2 pin plug is? Well yes and no.

If have a mix of older devices and TVs with newer ones, you may find that this is a source of noise and then one can try and reduce the noise by deliberately always connecting the power all the same way round. Especially if you have cables connecting these devices together and to newer devices.
 
Heavyonthemagick said:
^^They're all on the same circuit. That said, almost all homes have a single circuit, not? The separate lines from your DB all converge at the mains inlet via circuit breakers, so while you can isolate circuits, while everything is normal, there is only one circuit effectively... or multiple parallel segments of a single circuit, or am I mistaken?

I have some of those cables, though the cable to my TV is not one, I may just replace that with a ferrite magnet based one. As for lightning... spot on I have just recently replaced the Pi and Switch for that reason :)
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Yes they all are common in the DB board. BUT , fed via different CBs. Where issues have arisen with DSTV decoders installed with XV cabling between two decoders in different buildings that have completely separate power feeds not common except at the Council supply point, you can set up some really strange earth loops and ground currents flowing through the chassis of your devices.
 
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Geoff.D said:
So the older decoders with PSUs built into them, ( not the newer versions using external PSUs) have only a live and a neutral connection. With these units in theory, one could simply plug em in and not worry about which way around the 2 pin plug is? Well yes and no.

If have a mix of older devices and TVs with newer ones, you may find that this is a source of noise and then one can try and reduce the noise by deliberately always connecting the power all the same way round. Especially if you have cables connecting these devices together and to newer devices.
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Thanks - that's what I had heard I believe. So the typical figure of 8 power cable where the PSU is built into the unit is worth paying attention to.
 
Heavyonthemagick said:
Probably not the right forum, but here goes...

Is there anything that I can stick on my power line just before the HDMI switch I use to prevent noisy electronic gadgets from occasionally disrupting the HDMI signal? Whenever my tumble drier changes it's cycle ans turns the heater / motor on or off the screen goes blank for a second. Really annoying.
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Cheap ups for the hdmi devices.
 
Geoff.D said:
Yes they all are common in the DB board. BUT , fed via different CBs. Where issues have arisen with DSTV decoders installed with XV cabling between two decoders in different buildings that have completely separate power feeds not common except at the Council supply point, you can set up some really strange earth loops and ground currents flowing through the chassis of your devices.
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Aha, I have come across this with shielded twisted pair computer network cabling - it's possible to introduce an earth loop fault which (in theory) can have low voltage but with really high current... even being a fire hazard.
http://www.ee.co.za/article/earth-l...ective-short-circuit-psc-testing-methods.html
 
Heavyonthemagick said:
Definitely not a voltage issue. Bear in mind that most of these gadgets have intelligent power supplies that buffer the basics these days. That said, I have seen voltage fluctuate in some neighbourhoods - right from 120-270... depending on industry demand in the area. Our neighbourhood seems pretty good.
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It makes sure your voltage is clean and will filter out the obvious noise your other machines are giving.
Likely the Tumble drier drawing lots of power for the element then the motor kicks in (and uses a huge amount of power for a second to start the motor) then your power fluctuates (drops) for a second on the circuit, may even be feedback when the motor kicks in spiking the power a bit.
 
Heavyonthemagick said:
Aha, I have come across this with shielded twisted pair computer network cabling - it's possible to introduce an earth loop fault which (in theory) can have low voltage but with really high current... even being a fire hazard.
http://www.ee.co.za/article/earth-l...ective-short-circuit-psc-testing-methods.html
Click to expand...
Yes, with STP cables ground loops are common. Any shielded cables (like HDMI) do the same, as they link devices with low impedance wire.

On other thought. If you find that a distant TV cause problems, consider HDMI extender device which is using UTP Cat5 cabling. It will reduce ground loops on this link.
 
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AstroTurf said:
It makes sure your voltage is clean and will filter out the obvious noise your other machines are giving.
Likely the Tumble drier drawing lots of power for the element then the motor kicks in (and uses a huge amount of power for a second to start the motor) then your power fluctuates (drops) for a second on the circuit, may even be feedback when the motor kicks in spiking the power a bit.
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A true online unit will do that, but cheaper units are not online unfortunately. I doubt the switch will need pure sinewave, but it also likely outputs a square wave.
 
Heavyonthemagick said:
Been supporting systems for 20+ years and have some experience but not an electronics expert.
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Yea ditto, also lived on a plot with seriously dodgy power for the last 15 but what do I know :)

Where are you situated? I can give you a 2000va ups, but it needs batteries.
 
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AstroTurf said:
Yea ditto, also lived on a plot with seriously dodgy power for the last 15 but what do I know :)

Where are you situated? I can give you a 2000va ups, but it needs batteries.
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I'm in East London. I totally sympathise with you on the out of town electricity. That said some suburbs here are worse than farms when it comes to brown outs because of the poor infrastructure. It has improved over the past 10 years though.

How much do you want for the 2kva box? I have no issue buying new batteries and can send a courier. Pm me if you're willing to part with it :)
 
Heavyonthemagick said:
I'm in East London. I totally sympathise with you on the out of town electricity. That said some suburbs here are worse than farms when it comes to brown outs because of the poor infrastructure. It has improved over the past 10 years though.

How much do you want for the 2kva box? I have no issue buying new batteries and can send a courier. Pm me if you're willing to part with it :)
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Lol PM me, I'll reply through the day.

After the lightbulbs sang for the 3rd time I put everything on ups :)
 
Thanks Astro, I owe you!!
Lol @ lightbulbs singing. I know what you're talking about hahaha.
 
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