> Subject: strobe light power draw > Date: February 17, 2013 2:16:22 PM EST > To: lml@lancaironline.net >=20 >=20 > Amigos,=20 >=20 > My 24V strobe light systems draws 3-4 amps like Whelen says it should, = but seems to do it cyclically, i.e., a 0-4 amp sine wave with period = equal to the flash rate (about 3 sec). Can anyone tell me if that is = normal, or should it be a steady 3-4 amp draw? (12V guys, same question = only 12V Whelen strobes should pull around 7 amps) >=20 > < I ask because it's making prime alternator amps cycle up and down; = bus voltage cycle up and down, only about 0.1V; but it may be related to = the demise of two successive regulators for the backup alternator, which = starts kicking in at 3-sec intervals, with loud "BONG" alerts from the = Garmin. You are invited to enjoy the mental spectacle of the Garmin = BONGING me into insanity while I hurl epithets at the instrument panel = as I alternately shut off ALT 1, then ALT 2, then both, trying to figure = this out when I SHOULD be sitting back, smoking a stogie, and watching = the Texas hill country scenery slide by. PS -- Alternator one regulator = checks out good with good ground and power paths etc > >=20 > Charley --Apple-Mail=_9B916C99-7FC9-4288-88D0-299CE0B440F5 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=iso-8859-1 Hi = Charlie,

The strobe power supply does draw power = cyclically in sync with the strobe flashes. The inverter runs = continuously drawing low power after charging the strobe energy = capacitors and higher power during the recharge interval. This is a = relatively small fluctuation and is partially filtered by the strobe = power supply to insure it doesn't radiate and upset radio reception. It = does show up as current fluctuation in my G900 but will not damage an = alternator regulator. The autopilot has a similar current fluctuation = depending on how much the servos need to work in rougher air. Same = filtering needed in the autopilot controller and again not big enough to = damage anything in the charging system.

Current = fluctuations of any magnitude should not damage the charging system.... = think hydraulic pump or A/C compressor cycling. I would look at the back = up alternator's controller to isolate why it is kicking = in.

Hope this = helps.

Jack Morgan

On = Feb 18, 2013, at 6:03 AM, Lancair Mailing List wrote:

From: Charles Brown = <Subject: strobe light = power draw
Date: February 17, 2013 = 2:16:22 PM EST
To:

My 24V strobe light = systems draws 3-4 amps like Whelen says it should, but seems to do it = cyclically, i.e., a 0-4 amp sine wave with period equal to the flash = rate (about 3 sec). Can anyone tell me if that is normal, or = should it be a steady 3-4 amp draw? (12V guys, same question only = 12V Whelen strobes should pull around 7 amps)

< I ask because = it's making prime alternator amps cycle up and down; bus voltage cycle = up and down, only about 0.1V; but it may be related to the demise of two = successive regulators for the backup alternator, which starts kicking in = at 3-sec intervals, with loud "BONG" alerts from the Garmin. You = are invited to enjoy the mental spectacle of the Garmin BONGING me into = insanity while I hurl epithets at the instrument panel as I alternately = shut off ALT 1, then ALT 2, then both, trying to figure this out when I = SHOULD be sitting back, smoking a stogie, and watching the Texas hill = country scenery slide by. PS -- Alternator one regulator checks out good = with good ground and power paths etc = >

Charley

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