[TowerTalk] X99KP 12VDC RELAY FOR AMERITRON REMOTE

[Jim Thomson]

Date: Mon, 27 Sep 2010 20:50:48 -0700
From: Jim Lux <jimlux at earthlink.net>
Subject: Re: [TowerTalk] X99KP 12VDC RELAY FOR AMERITRON REMOTE
ANTENNA SWITCHES


And just how do you think they do a "double make" contact? :)

Bridge the two armature contacts on a dpdt or dpst relay and you get a double make spdt or spst.

##  whoa.  P+B makes SPST-DM  relays.  They are configured just like any contactor.  It's 2
sets of contacts IN SERIES.  The COM [ moveable part] is shaped like a 'T'... and comes crashing
down on the TWO 'throws.   One throw is the input, the 2nd  throw is the output.  Contactor's
are built the same way, except times  two or three.    The concept is when shutting off stuff like
motor's, etc, the back emf is split into TWO gaps, = zero arcing. 

##  IF you take a DPDT  or DPST  relay, and parallel all the contacts, you just get a 
higher current rated  SPDT  or SPDT.   I dunno if you would call it DM.   I would call it
redundant contacts.   It's an excelllent config, when using mech realys for remote switch's.
If you double the current rating, you quadruple the power rating. The way the poer can go open is
if both contacts go open. 

## The only other config that is reliable is  vac relays. 

Jim  VE7RF  




On Sep 27, 2010, at 8:39 PM, "Ron W8RJL" <youngron at verizon.net> wrote:

> For anyone who might be confused by the armature and parasitic verbage here 
> is what Allan Bradley has to say about Form X relays:
> 
> 
> A Form X contact arrangement is one which has single-pole, single-throw, 
> normally open double-make contacts. The function of this arrangement is to 
> close a circuit when actuated.
> 
> Forget about parasitics and armatures. It is just a contact configuration.
> 
> 73,
> Ron W8RJL