12V sense.... remote turn on???

Thread Starter

theeld

Joined Oct 5, 2006
12
I am on a design team that is developing some new hardware. Ideally we would like our device to be powered when an 12V switched power signal is sensed. The signal that we are recieving is not capable of driving our board/system itself. We are powering from a seperate 12V source. Essentially we want a voltage controlled Master Switch that is automatically switched on when the 12V switched power signal is present in place of a physical toggle switch or something. Obviously this sounds like a transistor or MOSFET, but there will be significant current flowing through the switch for long periods of time and am not sure if a transistor will survive over time. Any suggestions?

THEELD
 

beenthere

Joined Apr 20, 2004
15,808
Everything is a guess without some parameters, such as: voltage, current and nature of the signal.
 

tek_fool

Joined Feb 24, 2007
12
Well in my feild we use Solid State Relays,,sory I am just new to them myself and I am also switching a source remotely, however I am actually havning a little trouble witht he current wiring.
The device I am using it a Data logger that has a programable 12 volt switch channel,(it will switch on for a time period when a certain condition is true),this is preprogrammed into the logger and communication (sms alarm message on event ) takes place over a SAM (Stand alone modem).
It really depends on when/how you want it switched (remotely, on event,when condition is true,timed).

cheers
 

beenthere

Joined Apr 20, 2004
15,808
Actually, it depends on how you want it switched. I am merely trying to be helpful.
 

mrmeval

Joined Jun 30, 2006
833
Do both circuits have to be isolated from each other? What is the max current allowed to be drawn from the monitored voltage? Can this be a switch closure? Did you want the DC supply to the circuit to be turned on (not powered) by the monitored 12V?
 

Thread Starter

theeld

Joined Oct 5, 2006
12
The sensed 12V is not powering the board only switching the power to the board provided by a seperate DC power source. I am estimating current consumption to be at a max of 8-10 amps continuous for a period of 2-3 minutes and 1 amp 95% of the time.
 
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