tinvestor

I am trying to open and close a circuit with a pulse not a constant energy source does a relay exist to do this or do I need something different?

The pulse would be from a keyless entry system keypad.

Icemark

What are you really trying to do???

If the keyless has a pulse, you already have a signal to activate a relay

tinvestor

yes most of the relays i have seen require constant power to hold the circuit closed I cannot provide constant power nor can I find a relay that operates off a pulse.

By the way I was hoping and praying that you would answer. Thanks

Oops didnt answer the question. I am trying to allow and disallow power to given components

Haltech
switch panel
starter

Icemark

Okay, If I understand you, you need a relay that activates off of a pulse, and stays closed until another pulse??? Which it then stays open until another plus... right???

tinvestor

correct

Sideo

Ive heard of some called latching relays that are similar to that, dont know where to find one though

tinvestor

http://zone.ni.com/devzone/conceptd....256F1C006B7124

Here is a link to a dscription of those but I cant really tell if it is what I am looking for.
I think it would be the 2-coil latching relay?

tinvestor

I would need to be able to route the power to a specific coil for that to work and I only have the ability to send pulses to three different places and I origionally wanted four but had to settle for three as that is the limitation of the keyless entry system I am using. I wouldnt be able to even use 2 with this

Icemark

Yep, Mechanical latching relays. DEI (Viper alarms) makes one, as well as they are available from Digikey. Mind that the Digikey ones are pretty expensive (around $38 each last time I ordered 12 volt ones). I use the Tyco/Potter Brumfield S89R11DBD1-12 (DIGIKEY p/n PB514-ND) as it uses conventional .250 terminals (same size as regular 12 volt relay terminals) and is a 12 volt relay (actually will trigger with as little as 9 volts at 553 mA) and has a 15 amp contact rating. Single coil, dual make

The other option if you have a switched 12 volt on source (such as a key in the On position) then you can use a pluse to latch a conventional relay on, until the key is turn off. That takes two conventional relays and a 1n4004 Diode.

tinvestor

I think I like the idea of an auto off function that way I do not need to repulse to secure the vehicle.

this is a guess but you would wire the pulse to the first relay which would take the switched 12 volt source and close the load side to the diode that somehow holds the second relay open untill the switched 12V source that is running through the load side of that relay is lost and it will then return to an open circuit untill activated again?

I am still a little unclear how this works.

Icemark

I'll draw you a diagram... remind me with a PM if I still have not posted it by this weekend

tinvestor

thanks again Mark I will have to spend some time doing writeups this winter when everything is done and I am finished playing for the year.

wiring is not my strong suit, but I am trying to get a handle on everything.