Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 01-19-2019, 10:36 PM   #41
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 1,563
Default Re: 12 volt conversion

Quote:
I tried a voltage reduction device from speedway & it was too much of a drop in voltage, it would work fine on a constant load but not the horn
You could try 2 of them in parallel.
__________________
Talk slow, think fast.
katy is offline   Reply With Quote
Old 01-20-2019, 01:50 AM   #42
Mike V. Florida
Senior Member
 
Mike V. Florida's Avatar
 
Join Date: May 2010
Location: South Florida
Posts: 13,790
Send a message via AIM to Mike V. Florida
Default Re: 12 volt conversion

I goofed on the ohms law, it is early in the morning. Don't tell my boss, wait I have a union job never mind.

Let me see if I can explain this another way. My house has a 200 amp service going to it. This does not mean that I draw 200 amps. A car can have a 100 Amp alternator but the car will not draw 100 amps just because of the alt.

If the battery is run down to the point that it will accept 90 amps it would not start the car in the first place and the battery would most likely explode, if the main fuse that almost every A owner has installed, did not blow first.

I have never heard of this happening if you have can you cite a source. Nobody in our car club that has a 6 volt alternator has a 30 amp meter in it and none have burned up.

It is your car to do whatever you want to it. If it gets you on the road fine do it.
I'm just saying that unless you are going to add accessories to draw more than 20 amps the amp meter can stay and you can use the money saved on gas to keep you on the road (besides you would need to calibrate the wire you would use as a shunt to properly divide the current if you went in that direction).

The started can no way push off the gear ring as the system is designed.

Again to be crystal clear it is your car do with it as you want, my objection is that someone will make the choices based not on personal preference but on wrong information and even cause damage.
__________________
What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

Last edited by Mike V. Florida; 01-20-2019 at 02:01 AM.
Mike V. Florida is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 01-20-2019, 09:51 AM   #43
pinball73
Member
 
Join Date: Nov 2017
Location: North mo.
Posts: 62
Default Re: 12 volt conversion

Quote:
Originally Posted by BillLee/Chandler, TX View Post


Thanks guys! I got to have one! been looking for a long time
pinball73 is offline   Reply With Quote
Old 01-20-2019, 10:35 AM   #44
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Location: Wisconsin
Posts: 666
Default Re: 12 volt conversion

Quote:
Originally Posted by Badpuppy View Post
With a 12V conversion you should expect half the normal current reading as the 6V. If you add electrical accessories such as AC clutch and blower fans or - Lord save us - electric heaters, you should bypass the ammeter with properly sized wire.

An ammeter should not overheat within its dial range. If it does, the cause is faulty connections either internal or external. Wire terminals should be soldered for best connection. Those hardware store crimpers really don't do it.

------------

Last edited by 30 Closed Cab PU; 01-20-2019 at 11:18 AM. Reason: Removed double post info
30 Closed Cab PU is offline   Reply With Quote
Old 01-20-2019, 11:13 AM   #45
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Location: Wisconsin
Posts: 666
Default Re: 12 volt conversion

Quote:
Originally Posted by Badpuppy View Post
With a 12V conversion you should expect half the normal current reading as the 6V. If you add electrical accessories such as AC clutch and blower fans or - Lord save us - electric heaters, you should bypass the ammeter with properly sized wire.

An ammeter should not overheat within its dial range. If it does, the cause is faulty connections either internal or external. Wire terminals should be soldered for best connection. Those hardware store crimpers really don't do it.
I believe the current is the same, 6 or 12v.


When converting from 6 to 12, all the loads (coil, starter, lamps, wipers, etc.) have to be updated with 12 V components, or a Series limiting resistor installed on the 6V part.


Essentially; the 12v replacement has twice the resistance of the 6v part, or the series limiting resistor is sized the same as the 6V part and when put in line with the 6V part doubles the resistance of the 6V part for 12 v operation. Eitherway, way current is same: 6V part on 6V, 6v part with series limiting resistor on 12 V, or a 12 volt part on 12V.


An ammeter shunt is only needed when using alternators. They can deliver a max of current of 80-90 amps, pegging a 20 or 30 amp max ammeter. High readings can happen if the alternator is not regulated. Case of high output - short time after starting until the battery refreshes from starting. Longer high output - a partially discharged or bad battery, Halogen lights, lots of optional lights (cowl, fog, etch), air conditioning, etc. A properly shunted ammeter halves the current going through it, and you have to double the reading in your head to get a true reading.


For a long time I had difficulty getting my head around all this, info was spread out and I am not as quick as I once was learning/understanding all this new to me info.
30 Closed Cab PU is offline   Reply With Quote
Old 01-20-2019, 11:56 AM   #46
katy
Senior Member
 
katy's Avatar
 
Join Date: Jun 2015
Location: Alberta, Canada
Posts: 1,563
Default Re: 12 volt conversion

Quote:
Eitherway, way current is same: 6V part on 6V, 6v part with series limiting resistor on 12 V, or a 12 volt part on 12V.
Not true, when on 12 volt the current (amps) will be 1/2 of the current for a similar part on 6 volt.
If you have a 12 volt 50 watt bulb on 12 volts it will draw around 4 amps.
If you have a 6 volt 50 watt bulb on 6 volts it will draw around 8 amps.
Watts law, watts equals the voltage multiplied by the current in amperes.
__________________
Talk slow, think fast.
katy is offline   Reply With Quote
Old 01-20-2019, 01:27 PM   #47
Badpuppy
Senior Member
 
Join Date: Dec 2017
Location: Guthrie, OK
Posts: 280
Default Re: 12 volt conversion

^^What katy said. And the resistance of a 12V bulb is 4x that of a 6V of the same wattage: W/V = A, V/A =R. From katy's example, 12/4 = 3; 6/8 = .75.

If you add a series resistor with a device with the same resistance (horn motor) the power dissipation is doubled, since the current must remain the same. The resistor dissipates the same power as the horn in heat, rather than honking.
Badpuppy is offline   Reply With Quote
Old 01-20-2019, 01:55 PM   #48
Charlie Stephens
Senior Member
 
Join Date: May 2010
Location: Southern California
Posts: 5,762
Default Re: 12 volt conversion

The problem is not the discharge side (unless there have been a lot of changes) but the charge side.

Charlie Stephens
Charlie Stephens is offline   Reply With Quote
Old 01-20-2019, 02:17 PM   #49
MAG
Senior Member
 
MAG's Avatar
 
Join Date: May 2010
Location: Austin, Texas
Posts: 725
Default Re: 12 volt conversion

From Post 42.
"The started can no way push off the gear ring as the system is designed."

Are you really sure about that?
__________________
I noticed the harder I work the luckier I get!
MAG is offline   Reply With Quote
Old 01-20-2019, 02:32 PM   #50
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Location: Wisconsin
Posts: 666
Default Re: 12 volt conversion

Quote:
Originally Posted by Badpuppy View Post
^^What katy said. And the resistance of a 12V bulb is 4x that of a 6V of the same wattage: W/V = A, V/A =R. From katy's example, 12/4 = 3; 6/8 = .75.

If you add a series resistor with a device with the same resistance (horn motor) the power dissipation is doubled, since the current must remain the same. The resistor dissipates the same power as the horn in heat, rather than honking.


I see on your public profile you are a retired EE, so either I am having issues remembering theory learned 45 years ago and not used in depth since then(definite possibility), or we misunderstand each other. If fOK with you I will be looking at this more in the next few days, and PMing you - take this off line until I understand. Thanks for being patient, am just trying to understand.

Last edited by 30 Closed Cab PU; 01-20-2019 at 02:34 PM. Reason: Typo
30 Closed Cab PU is offline   Reply With Quote
Old 01-20-2019, 02:49 PM   #51
The Master Cylinder
Senior Member
 
The Master Cylinder's Avatar
 
Join Date: Aug 2012
Location: SoCal
Posts: 142
Default Re: 12 volt conversion

I enjoy these long drawn out threads that go way off topic but that is a good thing because maybe I will learn something (or become confused by incorrect info).

Unfortunately the OP has not been back for ~1 week so he can't take advantage of the same...
__________________
The Master Cylinder

Enjoying life at the beach in SoCal...
The Master Cylinder is offline   Reply With Quote
Old 01-21-2019, 12:50 AM   #52
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Location: Wisconsin
Posts: 666
Default Re: 12 volt conversion

-----------------------


Deleted, not sure my calculations used correct coil resistances.

Last edited by 30 Closed Cab PU; 01-21-2019 at 06:51 AM.
30 Closed Cab PU is offline   Reply With Quote
Old 01-21-2019, 01:22 AM   #53
30 Closed Cab PU
Senior Member
 
Join Date: Aug 2018
Location: Wisconsin
Posts: 666
Default Re: 12 volt conversion

I have not done the conversion from 6v to 12v , so it is all theoretical. How about getting feedback from member's who have done the conversion. Did current at the Ammeter increase or decrease substantially, or stay about the same?
30 Closed Cab PU is offline   Reply With Quote
Old 01-21-2019, 08:55 AM   #54
Kurt in NJ
Senior Member
 
Kurt in NJ's Avatar
 
Join Date: May 2010
Location: on the Littlefield
Posts: 4,472
Default Re: 12 volt conversion

Quote:
Originally Posted by MAG View Post
From Post 42.
"The started can no way push off the gear ring as the system is designed."

Are you really sure about that?
"as designed" means the ledge on the flywheel is still there , not broke/ worn off due to improper ring gear removal, and a ring gear that fits properly with the proper shrink, and tooth geometry
Kurt in NJ is offline   Reply With Quote
Old 01-21-2019, 12:19 PM   #55
MAG
Senior Member
 
MAG's Avatar
 
Join Date: May 2010
Location: Austin, Texas
Posts: 725
Default Re: 12 volt conversion

The ring gear is installed on the flywheel.. front- to- rear. Meaning, with the flywheel lying with the clutch side down, the ring is installed the top side. Pushed on until it reaches the ledge. It is held in place by friction/fit. The starter drive engages the ring gear from the back side. In effect trying to push the ring gear forward; i.e. toward the engine. The starter engaging force is opposite to the installation force.
Saw 3 cases of it last year.
One came completely off.
One came forward enough to cause a severe knocking. The ring gear teeth were hitting the webbing inside the flywheel housing. Drove it back on with a punch and tack welded it in place around the perimeter.
The third one was mine. I noticed it when the starter was removed for 12v conversion.
My ring gear was a new repo. that I installed when rebuilding the engine some 12K miles ago.
Do not know about the other two ring gears.
__________________
I noticed the harder I work the luckier I get!
MAG is offline   Reply With Quote
Old 01-22-2019, 11:25 AM   #56
jrelliott
Senior Member
 
jrelliott's Avatar
 
Join Date: May 2010
Location: Pine, AZ
Posts: 622
Default Re: 12 volt conversion

As stated before, running 12V conversion with original power house generator. Had a 12V alternator at first, then went back to 6Volts when I found the Power House. Went back to 12V as easier to find batteries here in the sticks. Wanted a 12V regulator, but Tom Westburg only has a 6V one. I am designing my own and now have the parts to build and test it. Wanted one that went inside the generator to control the field and not like Fun Projects which regulates the current and Voltage afterward.
jrelliott is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 08:05 AM.