What are you willing to define as "evidence" that the load is activited?
A specific level of current drawn by the load? Presence of 12 VDC at the
load? Switch to the load in the "on" position? Presence of the load's
output (e.g., sound, heat, light, motion, water flow, etc.)? The load's
output is usually, but not always, present when the load is drawing
current of course. An electronic navigation device could draw current
forever and yet not work at all.

The most obvious solution (power the relay with the same switch you use
for the load) is probably the most reliable method if all you want to do
is verify that power to the load is switched on.

Other seem to have figured out what you are seeking from your post, but
I can't see the info there.

Chuck





Electricky Dicky wrote:
On Sat, 4 Mar 2006 23:35:48 -0500, "jon doe" wrote:


Hi:
Looking for a simple circuit idea that will tell us when a 12V DC load is
activated. This is a critical load so we don't want to do anything that will
make it unreliable. The circuit just has to activate a tiny relay when the
load is going. Any ideas?
Thanks


Take a reed relay element and take a number of turns of your load wire
around it! If the required switched load is too great for the reed
then slave it through a larger relay!
Cannot get much simpler than that!

Richard

Nb "Pound Eater" Parkend G+S
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