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I understand Bob, but:
I had a 12V LED with 12V supply, and the wire from the EM-2 connected to the other terminal. I noticed that the LED glowed slightly all the time (very dim, but noticeable). I called and talked to Tracy, and he said to take a 5V lead out of the EM-2 and use a LED set up for 5V, that the 12V would overpower the circuit (my words not his) and allow a small current to flow through the LED, causing the dim glow. It was almost a year ago, but I believe that he said that if you use a filament bulb, it doesn't matter, but with the LED to use the 5V supply.
Bill Schertz
KIS Cruiser #4045
N343BS (reserved)
----- Original Message ----- From: "Bob White" <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, February 25, 2008 2:48 PM
Subject: [FlyRotary] Re: EM2 Warning light
Hi Bill,
My manual says to connect the + side to 12V unless the lamp requires a
different voltage. The output pulls the indicator light to ground, so
it shouldn't matter if it's hooked to +12 or +5.
If using an LED, a series resistor is required to limit the current.
The LED's that are rated at 12V have a built in resistor so an external
one isn't needed. A typical LED will have a maximum current rating of
around 30 ma and that may be too bright especially at night.
Something like a 600 ohm resistor would limit the current to between 15
and 20 ma. There is approximately 2 volt drop across the diode and the
bus voltage varies by several volts so the actual current will vary
also. A smaller or larger resistor can be used to adjust the
brightness. (Check the specs for the LED you use of course.)
Bob W.
On Mon, 25 Feb 2008 20:05:49 +0000
wschertz@comcast.net wrote:
Check the manual -- I believe that the warning light should be connected to a 5 volt source. At least if using LED's. An LED will glow all the time if fed with 12V, but if it is incandescent, it won't light up. The EM-2 connects to ground when alarming
Bill Schertz
-------------- Original message ----------------------
From: Bob White <bob@bob-white.com>
> Hi Bob,
>
> It sounds like a wiring problem. The warning light should be connected
> to the 12V bus on one side, and the other side is connected to the wire
> from the EM2. If it's an LED, then polarity of the LED is important > too.
>
> When a reading is out of spec on the EM2, the reading also flashes.
> That continues even when the ACK button is pushed. Are you seeing any
> of the readings flash off and on on the EM2 display?
>
> Bob W.
>
> On Mon, 25 Feb 2008 10:13:49 -0500
> bmears9413@aol.com wrote:
>
> > I dont have a warnig light hooked directly to the alternator. I > > understand
> that if any display on my EM2 is out of "spec"..the display will flash > and the
> warning light from the EM2 will light up untill you press the ACK > button. My
> warning light never lights up...for any reason so far.
> >
> > Bob Mears
> >
> >
> > -----Original Message-----
> > From: Bob White <bob@bob-white.com>
> > To: Rotary motors in aircraft <flyrotary@lancaironline.net>
> > Sent: Sun, 24 Feb 2008 11:02 pm
> > Subject: [FlyRotary] Re: EM2 Warning light
> >
> >
> >
> > Hi Bob,
> >
> > Warning light connected to the alternator? It should come on when > > you
> > power up and go out when the alternator starts putting out. If it's > > the
> > warning light from the EM2, it should start flashing when anything > > goes
> > out of it's range, and that's practically all the time when you're > > fist
> > setting it up. If It's not coming on at all it sounds like something
> > isn't hooked up right.
> >
> > On your water pressure, it should come up to cap pressure at the > > most.
> > Do you have an air cushion in your system. If not, the pressure will
> > go pretty high because of liquid expansion until a little liquid is
> > pushed into the overflow tank. 23 psi isn't going to hurt the > > engine,
> > but the EM2 calibration needs to be checked also. I was able to rent > > a
> > cooling system pressure tester from AutoZone which helped with the
> > calibration.
> >
> > Bob W.
> >
> >
> > On Sun, 24 Feb 2008 23:46:39 EST
> > BMears9413@aol.com wrote:
> >
> > > Is there a test mode on the EM2 warning lamp? My alternator is only > > > putting
> > > out 12.6 volts and my EM2 has the voltage flashing, as it should. > > > But my
> > > warning light doesn't light up. Shouldn't it? It hasnt lit up yet, > > > even
> with
> > the
> > > engine not started and 0 oil pressure.
> > >
> > > Bob Mears
> > > Supermarine Spitfire.
> > >
> > >
> > >
> > >
> > > **************Ideas to please picky eaters. Watch video on AOL > > > Living.
> > >
> (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/
> > > 2050827?NCID=aolcmp00300000002598)
> > >
> >
> >
>
>
> -- > N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> 3.8 Hours Total Time and holding
> Cables for your rotary installation - http://roblinstores.com/cables/
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
-- N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
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