Latching Relay?

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=15080
Printed Date: May 25, 2025 at 1:48 PM

Topic: Latching Relay?

Posted By: Dump
Subject: Latching Relay?
Date Posted: June 17, 2003 at 5:19 PM

Building a custom Harley with a magneto ignition. Magneto output is 80,000v to the plugs at 4 amps. Need to install a kill switch using a momentary switch on the right handlebar switch thru a latching relay. I think this is the only way I can do this and be safe about it and keep the switch on the handlebar where it belongs. When activated by the momentary switch, the latching relay must either complete the circuit (to run) or keep the circuit open (no run). Anyone got any ideas how? Any help would be greatly appreciated. Dump

Replies:

Posted By: the12volt
Date Posted: June 17, 2003 at 5:51 PM

Here's a similar set up for a starter kill relay that you should be able to modify to open or close the circuit you wish to interupt: https://www.the12volt.com/relays/page2.asp#psk

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Posted By: cool_greg
Date Posted: June 17, 2003 at 6:12 PM

you can buy relays that mechanically latch, put 12v on it for a short bit to latch it, then re-apply 12v to unlatch it

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Just a Guy, Wiring up those Vehicals
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Gool_Greg

Posted By: the12volt
Date Posted: June 17, 2003 at 6:51 PM

Yes, you could use a mechanical latching relay and an SPDT relay to open and close your circuit every time you push the switch, however if you only need to open your circuit when the ignition is off, you'll only have to push the switch once after you turn the ignition on with the set up I linked to above, but instead of interrupting the starter lead, you'd interrupt your circuit. As soon as the ignition is turned off, your circuit will automatically be interrupted, eliminating the need to push the switch again to open your circuit. This also makes it easier to determine the status of the interrupt.

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Posted By: djfearny2
Date Posted: June 17, 2003 at 8:55 PM

you can also use a pulse timer relay made by dei you can activate this relay by either a negative or positive input. and there is a timer on it from 0-90 seconds. if you need this relay to stay open or stay closed than this setup will not work by itself this can be used with another normal relay to either close a circut alowing it you to start the car and after the set time you will have to repress the button to activate the start wire. so basically with one pulse timer relay and a normal relay you can set it up so that you push the momentary button and it activated the timer relay for lets say ten seconds. or more and the timer relay activates the normal relay to complete the starter circut or what ever wire you want interupted more help email me. the model number for the timer relay is the dei 528t.

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Jon
Installer/Help Technician
---coral springs florida---
mecp certification is not always needed. I have it and it has not helped me out at all. my experience out shines it.