I think you could do it with a DPDT 2-coil relay and a momentary contact switch; one pole would be used only to power one of the coils and you'd use the momentary contact switch the common ground (for the coils). Hot the coils from the relay poles: The "OFF" coil would be connected to the output side of the main supply pole, the 12v power to the appliance (the other "throw" for this pole isn't used); the "ON" coil would be connect to the output side of the second pole which would be fed 12v from the 2nd (other) "throw" (the first throw would not be used on this pole which is used solely to provide 12v to the "ON" coil when the main appliance power is off). Only one (the right one!) coil has 12v volts on it at a time.
Caveats: &ou'd need to verify that the time constants worked out OK and switch bounce wasn't a problem. Also, the relay case might have to be isolated. Rufus > First Question of the Day. > > To control a load remotely on your new 12 VDC buss how would you rig up a > remote switch to operate either a one or two-coil latching relay so only > one wire (system ground and system 12 VDC is available at both the > switch(s) and the relay) would be needed to operate the relay using either > a center-off momentary toggle switch or two pushbuttons at the control end. > The one-wire would pulse at 12 VDC for one command, pulse at Ground for the > other condition and be floating otherwise. > -- Be Yourself @ mail.com! Choose From 200+ Email Addresses Get a Free Account at www.mail.com _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
