Author Topic: Electrical testing  (Read 841 times)

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Offline eigenvector

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Electrical testing
« on: October 14, 2017, 11:10:47 AM »
I have to ask this because I am puzzled by it.  Maybe I'm just not thinking about it clearly.

I'm testing the stator on my Sabre.
I have the regulator hooked up still, measure the INPUT voltage and it's reading 13.x VAC, except on one leg where it's 12.6 or something.

So I unhook the regulator and test again - this time I get 27.x VAC, and a single 26 VAC reading. AT IDLE.

I'm confused - why would having the regulator hooked up change the INPUT voltage from the stator?  In the back of my mind I'm guessing it has to do with the load the regulator puts on the input, but still I wouldn't expect it to drop by 50% just because the regulator is hooked up.

I've already decided the stator is questionable from the single leg that is down by a volt, now I'm just tying up loose ends - like why unhooking the stator is necessary for testing it.
Rob
--------------------------------
2018 HD Softail Heritage
1979 CB750K Limited Edition
1977 CB550K
1984 CB700SC Nighthawk
1983 VF750S Sabre

Offline TwoTired

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Re: Electrical testing
« Reply #1 on: October 14, 2017, 12:39:09 PM »
A voltage is excited in a winding wire when lines of magnetic flux cross it.  It only rises to a peak potential, if there is nothing draining it.

If a load is present, the peak voltage is diminished, as it is draining at the same time as it is trying to build up.  If the load is excessive, the voltage excitement is drained off before it can build.

Think of the stator windings as a bucket receptacle for excited electrons, the outlet wires as variable size hole in the bucket.  Big hole; the bucket, can't fill as electrons are siphoned off.  Small hole; the bucket can reach a nearly full state of max excited electrons.

Excited electrons = voltage potential.

Please don't confuse the terms regulator, with rectifier.  "Regulator" is a control mechanism.  "Rectifier" converts and connects a load.
There can be a configuration that includes both, but are separate functions within.

Cheers,

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline Steve F

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Re: Electrical testing
« Reply #2 on: October 14, 2017, 01:31:12 PM »
Dang, TwoTired.....THAT was excellent!
I learned something today!

Offline TwoTired

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Re: Electrical testing
« Reply #3 on: October 15, 2017, 01:50:32 AM »
Dang, TwoTired.....THAT was excellent!
I learned something today!
Glad you liked it.
Kinda my purpose in life to learn new things. Try to help others do that, too.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.