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Discussion Starter #1
Finished my obw today.
Welded for 30 seconds at 2000 rpm no gauges and than nothing.
How do I test the exciter diodes ?? ? ? ? ? also see next question.
Ford big case frame mounted YJ ,yes i have belt issues.
#4 wire, my ac/dc Lincoln runs this size.
Ran exciter directly to battery + using a clamp.
Assuming I have diode failure.
I bought a bridge rectifier on ebay 150A/1600v
I will bring out the field windings to it.
Where do I run the wire that goes from the brush to the exciter diode.? ? ? ? ? ? Ground ? ? ? ??????????????
Wont delta wind yet i can only count to 3
Please help
Mike
 

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You have your terminology all jacked up.... maybe you understand what you're talking about or maybe not.... hard to tell.

The diodes do nothing to "excite" anything. They are there to rectify the AC produced by the alternator to DC. The field winding is what you connect to the (+) terminal of the battery. This energizes the field windings which "excites" a voltage in the stator windings.

Is the bridge rectifier you bought off of ebay a 3-phase rectifier? Alternators produce 3-phase AC power, so you will need a either a 3-phase rectifier or 3 single phase rectifiers. You have to rectify all 3 phases of the stator windings. You can't just land all three of the stator legs on one terminal of a single phase rectifier.
 

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Discussion Starter #3
OBW In need of help.

Hi Thanks for the reply.
I have a wire going from a brush to a diode pack and a spade terminal. It is maybe 12 ga.
The other brush has a spade connector on the other end which goes out.
Could i have hooked up the wrong wire for exciter?
Yes it is a 3 phase bridge rectifier.
I am not sure which brush connections go to where,when i bring out the windings.
Michael
 

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Discussion Starter #4
I think i figuresd it out

The spade marked FLD goes to rotor brush.
The spade marked STA goes to rotor brush and to diod and to case ground.
I did have it hooked up right.

When i input 12v to terminal marked FLD it goes directly into the rotor windings.
That circuit than comes out the other brush and into diodes and to ground completing that circuit AH HA.
So the wire from diodes to brush is a diode ground wire and will not be used for anything.
And the STA brush will need to go to case ground but the spade terminal will not be used and the diode wire be cut close to brush holder.
What do you think.
Time for a star. nap and cookies
 

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Go ahead and eat your cookie and take your nap.... but hold off on the star. You're getting close, but your not quite there yet.
 

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Discussion Starter #6
Thanks Dad your swell

Thanks dad.
I hope my rectifier will fit in the case it is going to be close.
Keeping it in the case would be good for cooling and keeping wiring in the case.
Thanks for getting me thinking for myself.
Guess i should go ahead and delta wind it while i am there.
 

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The spade marked FLD goes to rotor brush.
The spade marked STA goes to rotor brush and to diod and to case ground.
I did have it hooked up right.

When i input 12v to terminal marked FLD it goes directly into the rotor windings.
That circuit than comes out the other brush and into diodes and to ground completing that circuit AH HA.
So the wire from diodes to brush is a diode ground wire and will not be used for anything.
And the STA brush will need to go to case ground but the spade terminal will not be used and the diode wire be cut close to brush holder.
What do you think.
Time for a star. nap and cookies
It will work like you've described, but your logic is a little off on the statement in red. The field wire coming off the brush does not go "into diodes" but does go to case ground. When used as an alternator, the (-) terminal of the rectifiers goes to case ground. Since both of these circuits go to case ground, they simply tied them together in a common ground. When used as a weldernator, one field wire goes to batterty (+) and the other field wire goes to (-) case ground. The (+) from the recitifer goes to one welding lead and the (-) from the rectifier goes to the other welding lead.

With the weldernator, if the (-) rectifier terminal is tied to the chassis ground, then you can only weld with DCEP polarity on your own vehicle. If the (-) terminal of the rectifier is islolated from chassis ground, then, in theory, you can weld on your own vehicle with either DCEP or DCEN polarity although most people would probably advise against DCEN to be on the safe side.
 

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Discussion Starter #8
Thanks for the correction.

I will run an isolated ground.
3 phase kind of spooks me. It can really kick the snot out of you and leave you smoking.
I have installed 175 amp Anderson connector to my frame just in front of the grill for my out leads and will have the same on welding leadsfor ease of setup.
I havnt fully tested my home made tensoner yet. Seemed to work ok.
lot of belt squeel though.
I will take the belt off when not in use.

Thanks much.


Sometimes i feel like i am not a total moron.

Than life returns to normal.
 
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