# Resolver reading backwards



## nolabama (Oct 3, 2007)

I have a resolver 

Amci ht-20-x

It is hooked up via a flexible coupling (a piece of hose and some duct tape) shaft to shaft

It is reading down not up. 

The HMI displays down from zero. 
-360 to -X whatever

I really would like this thing to count up in positive integers. That would be so nice. 

My tech support dingbats can't help

The contractor paid to make it work can't help

Internets please help.


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## nolabama (Oct 3, 2007)

This is the only document I have. 

http://amci.com/resolvers/ht20-x-resolver.asp


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## nolabama (Oct 3, 2007)

It's my understanding that pin out can be changed by two wires and reverse this tragedy.


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## varmit (Apr 19, 2009)

It appears that swapping "R1" and "R2" would reverse the input reference. This should reverse the readout response.


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## Big John (May 23, 2010)

It's been a while since I've played with one, so bare with me.

You have three sets of wires going to this thing? Should be one set for the excitation coil and then two position windings that produce a signal that's just like two-phase power: Two separate voltages 90° out of phase.

Swapping two wires of either position winding should correct the negative error, because as it stands it's actually generating a voltage of subtractive polarity compared to the other position winding.


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## nolabama (Oct 3, 2007)

Can't damage it if I swap the wrong wires?


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## nolabama (Oct 3, 2007)

R1 and r2d2 is getting swapped stat


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## TimGoon (Apr 22, 2014)

If I want something to go one way but it's going the opposite, what should I do? The opposite.


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## nolabama (Oct 3, 2007)

TimGoon said:


> If I want something to go one way but it's going the opposite, what should I do? The opposite.


I can't flip it over.


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## TimGoon (Apr 22, 2014)

nolabama said:


> I can't flip it over.


Do it electrically


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## nolabama (Oct 3, 2007)

TimGoon said:


> Do it electrically


Then , according to the documents I provided , which wires get swapped?


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## TimGoon (Apr 22, 2014)

Sorry I haven't looked at your link. Reverse the excitation leads. Take an ohm meter and ring on the pins, your sin and cosine leads will have the same resistance, the leads that are different should be your excitation.


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## TimGoon (Apr 22, 2014)

P.s. I've never done this, I'm just guessing as to how it could be done. Hope it helps


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## nolabama (Oct 3, 2007)

What would be my reference for ringing the pins? Ring all against each other? Ground?

If ringing them out gives what coil is what and they are R1 and R2 I may be on to something. Thanks.


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## Tsmil (Jul 17, 2011)

Swap s2 and S4

www.amci.com/pdfs/faqs/1f010.pdf


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