Impulse relay?
A simple challenge, I suppose: I want the battery-powered (growing ever more complex) circuitry in my cabin to switch off by itself when I forget to throw the switch as I leave for home. I forget too often; the battery runs empty - and kills itself. New batteries are expensive.
The auto-off-switch needs to handle 20A, and the voltage is 12V. In off mode it should have a minimal power consumption, in the order of 1-2mA max. I was thinking an old fashioned impulse relay, because it would consume zero power, but maybe there is a electronic solution to this?
The auto-off-switch needs to handle 20A, and the voltage is 12V. In off mode it should have a minimal power consumption, in the order of 1-2mA max. I was thinking an old fashioned impulse relay, because it would consume zero power, but maybe there is a electronic solution to this?
Comments
How were you going to tell that the cabin is unoccupied? You could use a Stamp or Propeller to provide a resettable timer that would turn off the power if time runs out.
Lots of options for doing that.
A micro switch activated by the door being unlocked/locked.
A switch you turn on when you enter and off when you leave.
A switch activated by hanging the car keys on it.
A PIR sensor(s) for the living area(s) combined with a load sensor for the bed(s).
IR/visible light cameras.
Sound/sonar detectors.
What you choose depends on your personal habits.
A simple solution would be to buy yourself a key-operated switch and get it mounted between battery and load in the cabin. You should fix the key to the switch together with the cabin-key. Then, to get lock up the cabin before you leave, you`ll have to switch the power off to get the cabin-key free so you can lock the door. Only thing is that you`ll HAVE TO remember to lock tha cabin.
That's great answer. I am also looking for answer of such type of question which Erlend ask. I think your answer is good answer. Thanks for sharing.
EDIT: @Mike Green, I cannot find anywhere where it is add-to-basket available. Tip?
Looks like there is no on line purchasing and only paper catalog available. A bit behind the times. I look after 3 brands of lighting controls and will take a look to see if one of the latching relays they use are suitable for your application.
handle 20A with minimal heatsinking...
Erlend
BTW
I don't want to go the mosfet way because there sure will be a short-circuit one day, and I doubt a fuse will save it. (Of course i could make a current limiting circuit, but relay is a quicker solution)