Arlid wrote to me suggesting several sources for latching relays to turn on/off loads connected to a buss using a remote switch. (see below)
The idea here is to turn on/off loads fed by the buss using just an 12 VDC impulse from distant switch(s) to a latching relay at the offsticker. Arlid suggests, for simplicity, two single wires instead of two pair, one pulsing the "on" coil, and the other pulsing the "off" coil, the other ends of the coils being connected to Ground at the offsticker. There are also latching relays available with one coil. Reversing the current through the coil toggles the relay on and off. However, I am even lazier than Arlid so I would like to run only one wire. 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. Second Question of the Day. I have two switches in the engine room to send signals to the helm. One closes to ground when the engine is overheated, the other closes to ground when the oil pressure is low. But I have only one wire available to go to the instrument panel where I have two lamps and a buzzer. How would I rig such a system using relays, diodes or other basic parts to light up the appropriate lamp and sound the buzzer. Of course I would not want any current flowing when there is no alarm condition. There is 12 VDC available (via a two-terminal oil pressure switch) only when the engine is running in addition to system 12 VDC and Ground at both ends.. >From Arlid: >>>Have a look at [EMAIL PROTECTED] for big amps relays. I looked at the fog light kit I picked up and they had a chinese no name relay there. However I have seen Bosch type relays used in latch mode. My preference is for the dual coil units like KG uses. It simplifies the wiring so a positive going pulse triggers it both ON and OFF. Any momentary push button pair will do. Several boat manufactures use this kind of switch from Carlingswitch to operate things like trim tab UP/DOWN or Anchor Winch IN/OUT Or you can use two door bell switches. Coil current is low so almost any switch will suffice. Industrial version swith 15A contacts are also available from OMRON Potter & Brumfield (P&B) Deltronic plus any relays tha tare plug pin compatible. Electrical wholesales like Wesburne or Grainger Digikey shoudl have a listing.<<< Norm S/V Bandersnatch Lying Julington Creek 30 07.695N 081 38.484W _______________________________________________ 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
