---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 04/25/09: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:21 AM - Re: LR3 regulator Amperage indications (Bill Schertz) 2. 06:35 AM - Re: LR3 regulator Amperage indications (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:21:14 AM PST US From: "Bill Schertz" Subject: Re: AeroElectric-List: LR3 regulator Amperage indications Bob, The heavy lead from the Alternator feeds through a hall effect sensor that is supplied by and read by a Blue mountain EFIS to supply a 0-5 volt signal that is calibrated for amperage. The Voltage readings are on the main bus, and also the e-bus (Reads a few tenths lower because of diode) and they are nice and stable. Bill Schertz KIS Cruiser #4045 N343BS ----- Original Message ----- From: "Robert L. Nuckolls, III" Sent: Friday, April 24, 2009 5:16 PM Subject: Re: AeroElectric-List: LR3 regulator Amperage indications > > > At 03:57 PM 4/24/2009, you wrote: >> >> >>Bob, >>Does the LR3 regulate the voltage by switching the current on/off? or by >>smoothly varying the field circuit. I have a data recorder taking samples >>every 5 seconds, and the current jumps up and down, while the voltage is >>quite steady. Is this normal? > > Where are you measuring current and voltage? The LR series > regulators are linear devices i.e. smoothly variable DC output > voltage. But without knowing exactly where you are sampling > voltage and current, I'm unable to deduce the significance > of your observations. > > > Bob . . . > > ----------------------------------------) > ( . . . a long habit of not thinking ) > ( a thing wrong, gives it a superficial ) > ( appearance of being right . . . ) > ( ) > ( -Thomas Paine 1776- ) > ---------------------------------------- > > > ________________________________ Message 2 _____________________________________ Time: 06:35:26 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: LR3 regulator Amperage indications At 08:17 AM 4/25/2009, you wrote: > >Bob, >The heavy lead from the Alternator feeds through a hall effect >sensor that is supplied by and read by a Blue mountain EFIS to >supply a 0-5 volt signal that is calibrated for amperage. > >The Voltage readings are on the main bus, and also the e-bus (Reads >a few tenths lower because of diode) and they are nice and stable. >Bill Schertz >KIS Cruiser #4045 >N343BS Okay, how much do the current readings "wiggle". Remember that a 3-phase rectified AC output alternators has about 5% pk-pk ripple on it. Further, there are diode switching transients that can expand the total pk-pk level of noise to 10% or so of bus voltage. Depending on the roll-off in frequency response of your data acquisition system, you may be sampling the effects of this noise. Try putting a 1000 ohm resistor in series with your sample sense line an a 10 mF capacitor across the line on the line away from the sense point. This will roll off your frequency response to about 100 Hz. See if this doesn't settle the readings considerably. The fact that your bus voltage is stable suggests that the phenomenon you're observing is a product of measurement technique and not a suggestion of poor system performance. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.