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Spikes in relay system

moonloopsun

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Hi guys.
i hope that someone can help us.
We moced to a new flat and installed an audio system in a room where we have 4 Shutters that are driven by a Shelly 2.5 relay.
the problem is that when the relays are starting or stopping the engine the turntable‘s preamp is picking a spike pop noise and amplify it.
we tried everything from the audio system‘s side (electric filters, surge suppressors, different cables...),
On the relay side the only thing we tried is to to wrap the cables with Ferrite clips.
we don’t know if the spike sound is created by the relay itself or the Shutters engine.
but we can’t use our sound system because those amplified pop sounds can destroy the speakers.
wirth to mention that in this room there is also a motorized beamer screen running by a different type of relay and it creates the same problem..
is there anyone that could possibly help us to understand what we have to do?

thanks a lot for your time.
 

danadakk

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.





The above on snubbers might help.


Regards, Dana.
 

Audioguru

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A record player? It should use shielded audio cables to connect to the amplifier's inputs.
Disconnect the record player and short the cables to see if the cables are picking up the interference.
Then disconnect the turntable's cables from the amplifier to see if the amplifier is picking up the interference.
 

moonloopsun

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A record player? It should use shielded audio cables to connect to the amplifier's inputs.
Disconnect the record player and short the cables to see if the cables are picking up the interference.
Then disconnect the turntable's cables from the amplifier to see if the amplifier is picking up the interference.

that’s the thing, i change all the cables, pre amp, amp, turn table.
i keep getting that spike.
it’s there also when the preamp is connected to the speaker directly without anything else.
i can eliminate it only when the electricity cable is connected to another socket 20 meters away. I tried audio high end surge suppressors and so on (5 different types). Currentky using Niagara 1200 from Audioquest. Still nothing filters it.....
 

Relayer

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when the relays are starting or stopping the engine the turntable‘s preamp is picking a spike pop noise and amplify it.

Can you check the relays that the spike suppression diodes for them are serviceable?
i.e. None have gone open circuit
Regards,
Relayer
 

BradtheRad

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i can eliminate it only when the electricity cable is connected to another socket 20 meters away.

No doubt because that other socket is on a different circuit breaker.
It suggests the click comes through house wiring on the same circuit breaker branch. It's hard to be sure what type of filtering, and where, is most effective.

In some cases it helps to reverse the orientation of the power plug. It was easy to do this when plugs only had 2 prongs. We experimented until we found the position which minimized hum from the speakers.
 

dick_freebird

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You could try powering the entire audio system
through an isolation transformer, and break the
ground as well as neutral and hot connections.
Somebody will say it's not safe to float the ground.
You might investigate running your own ground
wire to an earth-point, in this isolated power domain.
You'd like to think that wallplug ground is quiet.
But current spikes in the neutral can kick the local
ground back at the breaker panel if that's where
neutral is bonded to earth ground, getting into the
case of every electronic box in the lineup. And that
case might well be the audio reference ground,
so ground spikes turn into input-difference signal.
 
Z

zenerbjt

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I think you can try and replace the relay with a back to back fet or igbt switch........and make it switch at the mains zero crossing.
Or else you could have a big power resistor in series with the relay, and switch out the power resistor after some 20ms.

But yes, its best if the relay has an RC series circuit across it...then when the relay bounces the electricity can get snubbed into the rc series circuit...Dana above has kindly alluded to this. Make sure the cap and res are rated for the big mains voltage

So yes, first try with rc series circuit across the relay...be careful with electricity as you know.
You might be abkle to buy a relay with inbuilt rc series circuit snubber across it.
 

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