VR points to electronic

Ask Questions and Offer Advice Related to the Cessna 120 & 140 Type
Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
Post Reply
User avatar
6597
Posts: 402
Joined: Tue May 01, 2018 7:00 am
Name: David Sbur
Location: Vancouver WA KVUO
Aircraft Type: '46 140 0-200A
Occupation-Interests: Agriculture
Contact:

VR points to electronic

Post 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.
6298
Posts: 247
Joined: Tue May 01, 2018 7:00 am
Name: Randy Thompson
Location: California
Aircraft Type: Cessna 140
Occupation-Interests: Work on airplanes and engines
Contact:

Re: VR points to electronic

Post 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
Randy Thompson A&P IA Pilot
Hold STC SA547EA for installation of O-200 engine in Cessna 120/140 and 140A"s
Overhaul small Continentals
V529
Posts: 608
Joined: Tue May 01, 2018 7:00 am
Name: Victor G
Location: Michigan
Aircraft Type: C-120
Occupation-Interests: Work on airplanes till the cows come home..........they're still out.
Contact:

Re: VR points to electronic

Post 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
User avatar
6597
Posts: 402
Joined: Tue May 01, 2018 7:00 am
Name: David Sbur
Location: Vancouver WA KVUO
Aircraft Type: '46 140 0-200A
Occupation-Interests: Agriculture
Contact:

Re: VR points to electronic

Post 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.
6298
Posts: 247
Joined: Tue May 01, 2018 7:00 am
Name: Randy Thompson
Location: California
Aircraft Type: Cessna 140
Occupation-Interests: Work on airplanes and engines
Contact:

Re: VR points to electronic

Post by 6298 »

If you lower the maximum charge voltage the fluctuation may reduce or may go on and off as the battery voltage depleats.
Randy Thompson A&P IA Pilot
Hold STC SA547EA for installation of O-200 engine in Cessna 120/140 and 140A"s
Overhaul small Continentals
User avatar
6597
Posts: 402
Joined: Tue May 01, 2018 7:00 am
Name: David Sbur
Location: Vancouver WA KVUO
Aircraft Type: '46 140 0-200A
Occupation-Interests: Agriculture
Contact:

Re: VR points to electronic

Post 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.
Post Reply