Mains upgrade

Have you noticed that a hair about three inches long can grow out of your ear overnight? It's bizarre, and axiomatic of being older. 

Huge posted:

Adam,

Part of the explanation...

 Radio Frequency noise is conducted in two forms

Common mode: where line and neutral carry the same noise signal with respect to earth

Differential mode: where the noise is carried as the difference between the line and neutral

 Filtering of RF noise relies on the basis that the frequencies involved are a lot higher than the 50Hz or 60Hz of the mains

Inductors pass low frequency signals more easily than high frequency signals.
(If the current through the inductors tries to change fast, the rapid change causes energy to be stored in a magnetic field and released more slowly.)
Inductors are also known as ‘chokes’.

Capacitors pass high frequency signals more easily than low frequency signals.
(If the voltage changes rapidly the other side of the capacitor tracks that change, but slowly an electric field is built up that stores energy inside the capacitor as the two external sides of the capacitor return to lower energy states.)

 The usual approach to filtering involves both inductors and capacitors.  Place the inductors in series with the mains supply to block the high frequency getting through, and place capacitors across the mains so that any remaining HF energy is shorted to earth.

That’s the principle at least.  However, there’s a problem when a spike occurs.  In both inductors and capacitors electrical energy can be stored.  When used together and subject to a pulse (or sharp step) some of the energy gets rapidly passed back and forth between them; this is called ringing.  This is not what you want from a HF filter circuit.

So just using the inductors blocks some of the energy from the RF noise, without the ringing effect.  The reduction of the RF noise isn’t as great as with the circuit using both inductors and capacitors, but it doesn’t have the ringing problem.

Well that cleared that up then 

Roger

Hungryhalibut posted:

Have you noticed that a hair about three inches long can grow out of your ear overnight? It's bizarre, and axiomatic of being older. 

This crossed my screen just as I had a mouth full of tea and a client on the line. Terrible combination but quite a laugh.

Hungryhalibut posted:

Have you noticed that a hair about three inches long can grow out of your ear overnight? It's bizarre, and axiomatic of being older. 

Do old androids get wires hanging out of their ears?, and is that why they dream of electric sheep?

Mains spur with a ceramic fuse, the fuse wire should be 30/45 amp. This is directional btw. None swiched wall plug and piggybacked powerlines. Oh I'm sorry I forgot you guys aren't down under lol

and don't try this unless you know what you are doing and you must abide by your countries regulations......That was for the Richard factor and the general safety of the public.

Hungryhalibut posted:

Have you noticed that a hair about three inches long can grow out of your ear overnight? It's bizarre, and axiomatic of being older. 

Oooohhh get you, axiomatic !!!! .

No the real sign of getting old is not noticing, or more likely not at all bothered,  that the hair was growing.

Also for the creaking joints brigade  .......... https://forums.naimaudio.com/to...40#54786295722204340   

rjstaines posted:

Well that cleared that up then 

Roger

Perhaps you could contribute a better descriptive* understanding of L-C filters for us?

* i.e. not having to use integration and differentiation or complex numbers.