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One more bad Voltage Regulator

Was the picture in flight or taxi/low RPM?

I am watching mine too at 150 hours seeing the voltage lowering in flight, amps usually 1 or 2, and after a flight in taxi voltage dips to 12.4 or so and amps go negative. With RPM things go closer to my normal, but as of late not as perky.

I have my original VR with one on standby and a John Deere also on standby.

Was discussing the decreasing voltage reading and he suspected the VR, and noted the one in his Sonex has 500 hours on it. He speculated the location must be a good one. I will ask him more about next time I see him.
 
If you need or want an original replacement. https://www.dbelectrical.com/produc...ier-12v-for-900cc-ducati-darmah-61046750.html


I'm of the opinion that you shouldn't run anything off of the battery inside the firewall without the engine running, that would cause the main battery to get into a low state of charge. An AGM battery will take almost as much current as you can give it if it gets much below 90% state of charge or less.

This Ducati regulator is designed for motorcycles from the 1980's, that don't have power hungry glass EFIS with fans dragging the small light battery in a plane down while you play with settings with the engine not running, like in a RV-12. It's really a Rotax engine sourcing problem, once electrical needs increased with newer glass EFIS computer systems.

Find another power source if you need to run your Dynon or Garmin units for any length of time without the engine running, and you won't strain the Ducati Voltage regulators trying to recharge your battery. It's fine, if your engine starts quickly, for a top off recharge, but it gets overtaxed if you drain your main battery too low. Then too much current gets drawn while recharging, and solder joints start to melt, and ensuing failure occurs, IMHO.

Keep that battery voltage up in storage, 12.85V or more if you take a DMM reading.

I fly weekly, and see 13.13V on shut down, and usually 13.05V after a week without flight, on a DMM reading.

I now keep a 12v 150W solar panel in my hangar that puts out about 8.5 to 9 amps at 14.8V with a charge controller, that I used to keep with my travel trailer for off grid battery recharging. It's set up with Anderson Power poles. I'll usually plug it in for 15 minutes or so while I do my pre flight inspection. Then I remove it, put solar panel in the hangar, pull the plane out of the hangar, and go fly. I see very low amps being provided at 13.7 to 13.8v around 2500 rpm after start up. 4 amps charging rate, goes down to 1 or 2 in less than a minute.

IMHO, this is low level taxing on the Ducati Voltage Regulator, and helps keep the circuitry in side the VR good and cool.
 
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Headset Noise From Newer John Deere VR

Hi,

I have an RV-12 I bought last year. It had a John Deere VR installed in the cockpit, as per the plans when it was assembled, and the builder gave me one spare. I had to use the spare last year when the installed VR quit. The now installed VR hasn't been putting out as much voltage as it once was. Down to about 13.7 or 13.8 occasionally getting to 14. It used to be a steady 14.2 at higher RPMs. I had ordered two other spare JD VRs from Amazon last year at about $20 a pop so I decided to replace the one I had with one of my spares. With that JD VR installed I now get noise in the headset at anything above 2700 RPM. It is a fairly consistent wine and it gets louder as the RPMs increase. If I drop back below 2700 it is gone, or at least I can't hear it anymore. If I have the strobes on I can hear them. Tried the other spare i bought last year with the same result. Replaced the original spare and the noise is gone. Ordered another one from the Amazon source (now $28). Installed it and I also get noise in the headset.

So all of the 3 replacements I bought all generate noise in the headset. The original spare I have does not. The only difference I can see is that the 3 I bought all have gold connectors, the original spare I had has silver connectors.

Has anyone had a similar experience with any of the John Deere VRs purchased lately? Any possible solutions to using them and eliminating the noise? Any suggestions on what to move to if I need to go to another regulator.

Thanks for the help!
 
Some General Suggestions

Mount the voltage regulator using heat conductive paste between the mating aluminum surfaces.
Use a shroud and forced air blast tube to keep the regulator cool.
Connect a heavy 12 or 10 AWG wire from a mounting screw to the airframe.
I connected a thermocouple to my voltage J.D. regulator.
Maximum temperature is around 155 degrees F shortly after takeoff when the battery is recharging.
Cruise temperature is around 130 F with outside air temperature in 80s.
 
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