13 VDC switch

Looking for a ready made 13VDC electronic switch, that switches a
circuit on when voltage reaches 13+VDC - or a simple circuit. It would
be for optional devices I want to go on when the engine is charging and
off when not charging. Any sources? Not sure what to Google for.
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SQ2000 canard: http://www.abri.com/sq2000

Trivial to design and build.

Jim





"abripl" wrote in message
ups.com...
Looking for a ready made 13VDC electronic switch, that switches a
circuit on when voltage reaches 13+VDC - or a simple circuit. It would
be for optional devices I want to go on when the engine is charging and
off when not charging. Any sources? Not sure what to Google for.
-----------------------------------------------------------------
SQ2000 canard: http://www.abri.com/sq2000

Since its so trivial for you, how about a basic indication of the
components hookup or reference to the circuit elsewhere?

Anybody (else) know of a finished product source of this trivial
product? Kit?

RST Engineering wrote:
Trivial to design and build.

Jim

abripl wrote:
Since its so trivial for you, how about a basic indication of the
components hookup or reference to the circuit elsewhere?

Anybody (else) know of a finished product source of this trivial
product? Kit?

RST Engineering wrote:

Trivial to design and build.

Jim



Nope.

That's mostly a roll yer own.

Sounds like a relay circuit to me.

Off the shelf automotive supplies?
Wally World?

abripl wrote:

Looking for a ready made 13VDC electronic switch, that switches a
circuit on when voltage reaches 13+VDC - or a simple circuit. It would
be for optional devices I want to go on when the engine is charging and
off when not charging. Any sources? Not sure what to Google for.
-----------------------------------------------------------------
SQ2000 canard: http://www.abri.com/sq2000


Gonna need a bit more detail, alphabet...

Steve Foley wrote:
I remember a loooooong time ago, I was in a math class. We were being told a
story about some math genius who came up with a better something-or-other.
In the notes was a formula with the notation "Proof is trivial". In the
hundreds of years since, nobody has been able to prove that formula. It
appears to be correct, but it's never been 'proven'.

I believe it was "Interesting proof." And didn't someone finally work
it back out a couple of years ago?

I like the college professor who is lecturing and showing the steps to
solve a problem. Step 1...2...3... then as he writes down step three
he adds "and from there it is obvious that..." and writes down step
four. He backs up a minute, stares at the board, looks puzzled.
Mumbles to himself a bit, and finally wanders out of the classroom.

Students sit there puzzled. Five minutes go by, then ten. Suddenly
the professor reappears, beaming from ear to ear. "I was RIGHT!" he
exclaims. "It *IS* obvious!"

[And we need some more info about your "switch." Above 13 volts, below
13 volts, precisely at 13 volts? How much current?]

jmk

Steve Foley wrote:
"RST Engineering" wrote...

Trivial to design and build.

Jim

Not for me

----------------------------------------------------------------------------------

Yes, even for you :-)

Although he hasn't stated it very well, the original poster is probably
looking for a voltage comparator.

Some years ago I kitted and sold a simple on-off 'controller' based on
the LM-339 voltage comparator chip that would probably fill the bill.
Although sold as a solar controller, the circuit also served as a
low-voltage indicator, a means of turning on a motor-generator set and
a number of other functions, depending on what voltage was being sensed
and how you adjusted the set-points.

The circuit itself was little more than the practical application of
one of the several circuits provided by the chip manufacturer
(National, as I recall), making the 'design' a trivial task indeed.
The real value was in the circuit board and the accompanying article,
which appeared in 'CTM' magazine, in that you needed a precisely
adjustable power supply to adjust the set-points (ie, turn-on &
turn-off). In the article I provided a schematic for such a power
supply, cobbled up from a salvaged wall-wart, regulation provided by an
LM-317T.

Unfortunately, the original poster's use of the term 'charging' needs
to be defined in electrical terms, and the chances off finding exactly
what he wants in an off-the-shelf package is probably somewhere between
slim and none. But there are numerous examples of such circuits out
there, assembled as well as kits.

-R.S.Hoover

In article .com,
"abripl" wrote:

Since its so trivial for you, how about a basic indication of the
components hookup or reference to the circuit elsewhere?

Look up zener diode for starters.

This is starting to smell very much like the upcoming November Kitplanes
column.

Jim


"cavelamb" wrote in message
k.net...
abripl wrote:
Since its so trivial for you, how about a basic indication of the
components hookup or reference to the circuit elsewhere?

Anybody (else) know of a finished product source of this trivial
product? Kit?

RST Engineering wrote:

Trivial to design and build.

Jim



Nope.

That's mostly a roll yer own.

Sounds like a relay circuit to me.

Off the shelf automotive supplies?
Wally World?

You mean I started a new idea? It sure would be handy to plug in
portable devices into the cigarette lighter socket source and not drain
the battery with engine off. OR in case of charging system failure
some non-crucial devices could be turned off automatically. We need
this before November.

RST Engineering wrote:
This is starting to smell very much like the upcoming November Kitplanes
column.

Jim