Fotios need help with input selector. Rotary switch or Relays?

[jacco vermeulen]

Originally posted by fotios
who is the type of these relays.

DS-2E, now NAIS, used to be SDS (Sicher Durch System) in Deisenhofen Germany.

SDS history : here

[jacco vermeulen]

Before NP slaps me again, he's using the Panasonic DS2E versions.
Same Same, NAIS/SDS/Panasonic= all Matsushita.

edit: me forget datasheet again.

[multi-volti]

I think Cliff's got a pretty good pragmatic answer. I have learned not to discount any claims about voodoo because I learned that some of them are true...then there are others I have to draw the line at for reasons of practicality and sanity.

Alot of times when a particular component technology is disparaged for reliability reasons, it is sometimes because it was misused. I worked somewhere people decided certain brands of op amps were bad because their active filters oscillated - HELLO, do you SMELL how crappy your design is? It doesn't work with the op amps that are closer to ideal (higher gain) -sorry ,off topic...

I personally have never used mercury wetted relays for audio - so I don't know. I liked them in the days of tubes (oh, wait, we ARE still in the days of tubes) because the contacts are more forgiving about not welding when switching bigger things that audio.

[fotios]

Originally posted by fotios
Thus I revised my opinions for relays and thought that sure certain factories found the way to construct noiseless relays (I mean without the danger of electromagnetic interference). I search in the sites of all companies for one month and still I could not locate with certainty who is the type of these relays. Of course I suppose for some that they have these specifications, but I cannot be based in the document of constructor or the seller of them.

Originally posted by jacco vermeulen


DS-2E, now NAIS, used to be SDS (Sicher Durch System) in Deisenhofen Germany.

SDS history : here

Originally posted by jacco vermeulen
Before NP slaps me again, he's using the Panasonic DS2E versions.
Same Same, NAIS/SDS/Panasonic= all Matsushita.

edit: me forget datasheet again.

Bravo Jacco. Exactly this information i wanted. Thanks man, you make my day because already i have bought 12 pieces of DS2E of NAIS from my local supplier before one week (fortunatelly NAIS is distributed in Greece and the local distributor has stock!). I am obliged to you. Now i can go to sleep. Tell me your address to send you a bottle of "CHIPOURO' of much more higher quality from "OUZO".
Fotios

[fotios]

Originally posted by sandyK
mzzi
It was mainly switching use in Telecommunication relay sets as used in Crossbar Telephone Exchanges, but varied types of use and coctact switching requirements as to current and voltage.
SandyK

sandyK
In the photos that i have received from you, to big luck the input relay PCB it has the same type relays from these that refers Jacco Vermeulen. Thanks my friend.
Fotios

[fotios]

Originally posted by cliff
Reed relays have their contacts sealed in an inert gas filled glass tube.

They are specifically designed for low level switching without any self-cleaning.

I have used miniature reed relays by the tens of thousands switching nanovolt level signals in automatic test systems. They will effectively last for ever unless abused with inductive loads.

With only 2 or 3 pF between contact and coil, any feedthrough of noise in the audio bandwidth and at reasonably low impedences is negligable

Thanks Cliff for your really esential information. This type of reed relays you refer has contacts from Gold coated or mixed with Ruthenium (a member of platine familly) and marked as "Ru" usually. Thanks again for your precious experience offered.
Fotios

[anatech]

Hi Fotios,
Many telecom relays are also gas sealed types. Inert of course.

From all relay constructors untill now only from the OMRON i have seen noise figures in dB caused from the electromagnetic interference of coil when activated.

There are two things you can do here. Shape the on and off current ramps. Run the coil from a clean supply. Then there will be no noise emitted from the coil.

Hi Sandy,
Isolating the ground from all video sources would be very worthwhile. Things like tuners (unless connected to cable antenna) and CD players would not have very much noise on their grounds.

Excellent point though. Using a dual deck, four contact rotary switch might be the best plan. Ground sections make before break to avoid a "no ground" hum that may occur.

-Chris

[sandyK]

Chris
Inevitably , when you have a full complement of inputs from various sources, and piles of cables, audio,video and SPDIF, together behind a cabinet, and you turn up to full gain, when the grounds are also switched you will hear different levels of hum from many sources, From some sources there will be dead silence. This method allows you to isolate the poorer inputs, and optimise cable routing etc. Perhaps even to improve the equipment that does not respond to better cable routing clear of mains leads.
Regards
Alex

[anatech]

Hi Alex,

when the grounds are also switched you will hear different levels of hum from many sources, From some sources there will be dead silence.

Very true.

Sorry for calling you the wrong name. Pardon me, your handle throws me off.

This method allows you to isolate the poorer inputs, and optimise cable routing etc. Perhaps even to improve the equipment that does not respond to better cable routing clear of mains leads.

Absolutely!

I design my equipment enclosures with this in mind.

-Chris

[smithy666]

If you're worried about electromagnetic interference from the energised coil, you can use latching relays, which don't use any power once switched. This could alleviate your concerns.

I have been using relays mounted at the RCA input point for abour 12 years and I find them far superior to switches. Prior to that I used switches but these became very noisy after only a few years and were a pain to clean. Go relays for a hassle free long life (use the best quality)