Vibrator Using Transformer

[eyad267]

Dear Guys...
I have seen something that i am not so familiar with and i need some help explaining it...

A transformer is connected to a VFD with two phases only out of the three phases output of the VFD, and used as a vibrator to a steel circle aligned exactly above it so the circle vibrates continuously to move some pieces...

what is the theory behind that? and why it is allowed to connect 2 phases out of the U V W phases of the VFD?

Thanks in advance

 

[freddofrog]

i dont see anything wrong with this, its very common in cement, ashphalt and quarry industries.

Its ok to use 2 phases as long as the maximum primary voltage of the vibrator transformer isnt exceeded. Its common to use this where sometimes light product like cement will create a bridge effect that needs to be dislodged. Its just a form of vibrating feeder.

 

[OkiePC]

Is it really a transformer? Or some sort of specialized motor?

 

[eyad267]

yes it is a transformer... just how is it happening? the theory behind that

 

[leitmotif]

Dear Guys...
I have seen something that i am not so familiar with and i need some help explaining it...

A transformer is connected to a VFD with two phases only out of the three phases output of the VFD, and used as a vibrator to a steel circle aligned exactly above it so the circle vibrates continuously to move some pieces...

what is the theory behind that? and why it is allowed to connect 2 phases out of the U V W phases of the VFD?

Thanks in advance

Can you send a picture of the components? You just turned on my curiosity

Dan Bentler

 

[Andybr]

This sounds exactly like an electromagnetic vibratory conveyor. The magnets normally look like a transformer but obviously have no secondary winding. Most of the units I have seen use a purpose built drive but I did come across some a few years ago which used a slightly altered Yaskawa VFD.

 

[panic mode]

dithering can be used to eliminate effects of friction in a mechanical system:
http://en.wikipedia.org/wiki/Dither

 

[freddofrog]

I have seen them as Transformers. As the trasformer magnetic flux increases it will Pull a ferrit lever and disconnect the circuit, as it collapses, it will energise again.

if its off unbalanced rotating wheel type. its a single phase motor operating at 240vac or 415vac (adjust voltage to suit country)

 

[eyad267]

I guess that freddofrog has come so much near the actual situation, ive been looking for the feeders after your reply and it seems to be the actual situation...

this website shows a picture near the one used in our factory http://www.clevelandvibrator.com/equipment/feeders.php
same alignment but with a transformer and VFD below the rack.

anyway according to the replies, what do you mean by the bridge effect? i am not so familiar with this information and i couldn't find alot about it in the internet?

Thanks in advance