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VR points to electronic
Posted: Wed May 02, 2018 8:20 am
by 6597
OK, let's get this forum going here gang....
My bird has an old vibrating VR Cessna: C611001-0101, 60amp alternator ala' Cessna 150 wiring on an 0-200A, and when I attach a volt meter to the buss while cruise flying it seems to jump +/- half to one volt. Not changing the load, but wondered if this is normal for a points-type VR.
I did chase down some wilder fluctuations on the volt meter from my old coffee grinder rotating beacon, which had a poor wire connection I repaired.
Contacts cleaned, before I get all excited and start looking at replacing the VR with maybe a Zeftronics want to verify that's what these old point VR's do.
Re: VR points to electronic
Posted: Wed May 02, 2018 11:22 am
by 6298
6597 wrote: ↑Wed May 02, 2018 8:20 am
OK, let's get this forum going here gang....
My bird has an old vibrating VR Cessna: C611001-0101, 60amp alternator ala' Cessna 150 wiring on an 0-200A, and when I attach a volt meter to the buss while cruise flying it seems to jump +/- half to one volt. Not changing the load, but wondered if this is normal for a points-type VR.
I did chase down some wilder fluctuations on the volt meter from my old coffee grinder rotating beacon, which had a poor wire connection I repaired.
Contacts cleaned, before I get all excited and start looking at replacing the VR with maybe a Zeftronics want to verify that's what these old point VR's do.
When the voltage get to the set value, the points open and the charging stops. If the voltage starts down the points will close and charging will start again. The voltage difference is normal. IMHO
Re: VR points to electronic
Posted: Thu May 03, 2018 8:05 pm
by V529
Are you using a "Modern" volt meter? i.e. digital? Then yes, that is rather normal. If you used an old analog (dial type) simpson or something, I doubt you would see that much variation. That does sound a tad more than "normal", but digital voltmeters show all the skeletons.
Victor G
Re: VR points to electronic
Posted: Thu May 03, 2018 8:42 pm
by 6597
Victor,
Yes, a Fluke digital meter. I'll have to grub around for an old analog meter. It is quite a show but I guess it shows all the warts of a points VR, hadn't thought about that.
Re: VR points to electronic
Posted: Thu May 03, 2018 9:01 pm
by 6298
If you lower the maximum charge voltage the fluctuation may reduce or may go on and off as the battery voltage depleats.
Re: VR points to electronic
Posted: Thu May 03, 2018 9:19 pm
by 6597
Thought of that. I have an Odyssey PMA'd battery that apparently the factory suggests 14.2-14.8 charging so that is kinda weighing on me at the moment.