Relay question

Jim Brain brain at
Fri Nov 28 01:23:25 CST 2014

I know this is not an electrical forum, but I thought perhaps someone 
has seen what I am looking for.

For an application, I am looking for a relay that is connected to 12V 
through a switch, with the switch voltage also going to the middle of a 
SPDT relay contacts.

  * If I energize the latch once, for the time the button in pressed,
    the relay flips "on" and the middle relay contact sends power to the
    NO contact
  * If the energize the latch a second time, for the time the button is
    pressed, the relay flips "off" and the middle relay contact sends
    power to the NC contact.

The circuit works with an open relay of the kind they used to use in 
garage doors (push button once, and door goes up, second press makes it 
go down...)  But, we need a sealed relay to beat the weather (it's for a 
lineman's bucket truck we own).

Simulating this with some electronics and two relays won't work (well, 
it would work, but it's for my father, and he really wants a 
electrical/mechanical relay solution, like he has, but weathertight).

I thought for sure there was such a thing as a D-type FF in relay 
format, but all of the magnetic and mechanical latching relays I see 
online use two separate coils to operate, which means two switches, and 
that won't work (no more signal paths available in this application).

I must not know what to call what I am looking for, and was hoping 
someone had a better name for this type of thing or a suggestion of 
where to look...


Jim Brain
brain at

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