Looking for a 5PDT or 6PDT sealed relay, 28V, low current contacts

[Peter]

I wonder if anybody has any kicking around...

It needs a 28V coil, preferably with gold contacts so it can switch
low currents. Most really sealed relays are milspec metal case ones
of this general style:
http://www.ebay.co.uk/itm/12-Volt-R...al_Components_Supplies_ET&hash=item257839a5ee

but I can also use plastic cased relays so long as they are fully
sealed e.g. the Panasonic K6EB24
http://uk.rs-online.com/web/p/non-latching-relays/3992542/

which is recently discontinued (and anyway Panasonic relays were
always on a 1 year lead time).

I've checked mouser.com and digikey and can't see anything there. They
probably do some but their websites have no many items with no images
it's hard to find one.

There are many 6PDT milspec relays on US Ebay but nearly all are
shabby 50 year old ones. Just a few are still 40-50 years old but in
original bags so not too bad, but I would like gold contacts, and I
believe silver contacts are not so good (not sure that is actually
true).

I know one can make one up with two 4PDT ones but I want to avoid the
potential of some contacts closing and not others. I know there is a
way to detect that (by wiring contacts on different relays in series
and checking for continuity) and in fact I will be doing that anyway.

I actually need 4PDT with the 5th contact being used to confirm it
switched.

If anybody has a couple I would buy them, Paypal...

 

[Jasen Betts]

I know one can make one up with two 4PDT ones but I want to avoid the
potential of some contacts closing and not others.

I don't see how using 5-pole relays will ensure that.

 

[[email protected]]

It needs a 28V coil, preferably with gold contacts so it can switch
low currents.

A TE / Axicom V23030J1021A106 is 6PDT, 24 VDC coil, silver with gold
flash terminals. It is "environmental category of protection RTIII",
which is apparently one step below "sealed":
http://www.relaymaster.com/Glossary.aspx#Category-of-protection-IEC-61810
Digi-Key has no stock but says it is orderable; US$178 each in a minimum
quantity of 5.

Why do you need it to be sealed? That appears to be the tough part of
this spec.

I know one can make one up with two 4PDT ones but I want to avoid the
potential of some contacts closing and not others.

How about sticking a solenoid on top of some regular snap switches
("Micro Switch" style)? Mouser lists several of these style of switches
with IP67 ratings. If you get the kind that have holes through the
body, they are relatively easy to gang up by stacking them up and using
long screws. They probably won't all switch at precisely the same time,
if that is important in your application.

You could also stick a solenoid on top of a Honeywell 426EN9-8 switch
from Mouser - 6PDT and sealed to MIL-S-8805 symbol 4. They have 9 in
stock at the astonishingly low price of US$1,752.08 .

Matt Roberds

 

[Don Y]

A TE / Axicom V23030J1021A106 is 6PDT, 24 VDC coil, silver with gold
flash terminals. It is "environmental category of protection RTIII",
which is apparently one step below "sealed":
http://www.relaymaster.com/Glossary.aspx#Category-of-protection-IEC-61810
Digi-Key has no stock but says it is orderable; US$178 each in a minimum
quantity of 5.

Why do you need it to be sealed? That appears to be the tough part of
this spec.


How about sticking a solenoid on top of some regular snap switches
("Micro Switch" style)? Mouser lists several of these style of switches
with IP67 ratings. If you get the kind that have holes through the
body, they are relatively easy to gang up by stacking them up and using
long screws. They probably won't all switch at precisely the same time,
if that is important in your application.

You could also stick a solenoid on top of a Honeywell 426EN9-8 switch
from Mouser - 6PDT and sealed to MIL-S-8805 symbol 4. They have 9 in
stock at the astonishingly low price of US$1,752.08 .

Mount a bunch of reed switches in a coil? I.e., the switch contacts
are "under glass"...

 

[Greegor]

Mount a bunch of reed switches in a coil? I.e., the switch contacts
are "under glass"...

Quaint!

Didn't they make SPDT reeds once?
I seem to recall some with two contacts
on one end of the glass capsule.

Magnet biasing and all was sort of an art.

With the right magnet biasing you could
even make regular reeds function as
normally closed, right?

Isn't this a bit too retro, like using 555's?

Visions of dozens of raw reed capsules
stuck in one great big electromagnetic coil..

Shades of the 1970's...

 

[Peter]

Mount a bunch of reed switches in a coil? I.e., the switch contacts
are "under glass"...

I need changeover contacts. One can get CO reeds but less commonly.

Also I think with a single relay it is less likely for one contact to
operate differently to the others.

 

[Peter]

[email protected] wrote

Why do you need it to be sealed? That appears to be the tough part of
this spec.

It is for switching signals in a light aircraft. One wants protection
from humidity, which *will* get in given the air pressure swings.

The traditional solution in avionics is an old box from e.g. Northern
Airborne (RS08 etc) which contains 2 or 3 cheap 4PCO relays and they
usually are wired with one contact on each all in series so the stuff
being switched can tell if one or more of the relays has failed to
move. But these boxes are quite bulky and IMHO badly made and open to
corrosion everywhere except inside the relays.

One can get the small 4PCO relays used in the RS08 from
IMO/SDS/Panasonic (EN4 or DS4 series) and these are normally sealed.
The IMO ones are even nitrogen filled. All these great relays are now
discontinued - example
http://www.ebay.co.uk/itm/10-NEW-PI..._DefaultDomain_0&hash=item1e7c635ed5#shpCntId
I think these were widely used in telecomms but the market seems to
have died.

There are other more expensive relays that will do it, but the lead
times are silly.

 

[Peter]

I don't see how using 5-pole relays will ensure that.

There is no way to completely ensure that...

 

[John S]

The picture on the Web site looks like a dip switch, so it is
misleading. The data sheet is what to examine.

Good find, John.

John S

 

[[email protected]]

[email protected] wrote


It is for switching signals in a light aircraft.

I don't have an A&P. I don't even have a TG&Y. If your airplane falls
out of the sky, I never heard of you. I also don't like buying lawyer
food - not even a little bit - so I wish you luck with your project.

Matt Roberds