This is for a new project and I need a way to do this:

I need an SPST relay to control the voltage going to a part of the circuit.  However, I need the relay to change states (open/closed) with a pulse of 9 or 12V+.  I can't seem to find them anywhere.   Any ideas?  Thanks!!!

How much voltage are you switching (i.e. do you need a relay, or could a linear switching IC do)? It sounds like you might need some sort of flip-flop circuit with a relay driver tacked on the end; so it's not really the relay that you are after (IMHO) but the appropriate relay driving circuitry.

I'm 99% positive RG has info on his site for relay driver stuff that changes state with momentary switch toggles or voltage pulses; you can always divide down the incoming voltage pulse if it is too high for the design there.

HTH! (does it? )

Mike

Well I need this for two unrelated projects.  One is a huge switching system for my effects, the other is for my car.  THe car project is giving me the most trouble since we are dealing with a few amps of 12V power, not just a 9V battery.

then U need 2 types of relays.
4 the stompbox---a read relay.
4 the car---a power relay.
U can find both @ www.mouser.com.
i have a stack of DIP read relays.
i think, SPST(?)
$2 each + $1 shipping.
these are *not* "latching" type.
they use 5VDC for the coil.
U can build a power FlipFlop from
2 descrete transistors 2 "latch"
the relay on.  
Pulse once--on; pulse again--off.
PM me 4 more info.
staytuned
tone

Thanks!  I'm having trouble finding just the right power relay, but there are a few out there.  Alot of them are just non-latching relays, they don't remain in the last state which makes the search alot harder.  If you come across one for 12V and 15A+ that would be amazing!

@ mouser there are magnecraft 12V latching relays.

page 1952
http://www.mouser.com/catalog/619/1052.pdf

highest amps i C is 10A, woth 12V coil.
they're *not* cheap...

go to www.mouser.com

search:  "relay"

when search comes up
select "magnacraft latching relays"
browze 2 2nd page...
must say "in stock"
there are other brands.
afn
tone

So is that all I need, a latching relay.  I've been asking around and no one seems to know how latching relays worked.  So I send a pulse of current across the coil and it switches and stays, then do it again and it switches back?  That would be so perfect, regardess of cost.  I just need to make sure it will work.