# PCB Heaven

## General Category => Maths, Geometry, Physics and others => Topic started by: spic0m on March 10, 2008, 02:52:25 AM

Title: Motors
Post by: spic0m on March 10, 2008, 02:52:25 AM
Hi everyone!
I'm using Dr. Calculus a for some time and its been very helpfull, also the whole site is very good, congrats!
I'm not that experienced with electronics and staff but i'm willing to learn.  ???  ???  ???
I have a question that might be off topic but i will ask it  :), also i think it'll be a good idea if the site expands its field of interest and subjects.
To the question ....
I have a 3 phase motor and i want to know if the coils are burned or damaged in any way, whats the measurments i should take to find out??? Is that mesurments apllies also to dc and servo motors???
If you think i'm out of topic of the site just erase this.  :)
Title: Re: Motors
Post by: kam on March 10, 2008, 09:02:05 AM
If you think i'm out of topic of the site just erase this.  :)
It is not really you out of the topic. It is us that we have run out of topics  :) :) :)

Actually we should have a MOTORS topic somewhere. It will be done.

Well, a 3 phase motor has 3 coils. Thus, 3 coils means 6 connections. I think you have met before these 6 pairs of connections. They are called RST from the input side and UVW from the output.
Each coil uses 2 of these pins, so coil 1 has R and U, coil 2 has S and V and coil 3 has T and W.

1] To check first that there is no circuit break, you must measure the resistants to the coils and you must find approximately the same resistant. For example you must find 4 Ohms between R-U and S-V and T-W.

2] Then, to ensure that there is no sort-circuit, you must measure the resistant between the inputs of the coils. You must find it infinate. The measurements are R-S, S-T and R-W. For being sure you can also measure the outputs (U-V,V-W,U-W).

3] To ensure that there is no current leak, you must now measure the inputs of the coils to the ground. This must also be infinate. (R-N,S-N,T-N and you can also measure U-N,V-N,W-N).

If all other above are correct, then your motor should work.
Title: Re: Motors
Post by: spic0m on March 10, 2008, 23:49:21 PM
Thanks alot man  ;D  ;D  ;D  ;D
Except the motors topic you mentioned i believe that all of us have their own "sources" which they dig for info or bying, so why not make a page with all the links in categories and all add theirs?
Title: Re: Motors
Post by: kam on March 11, 2008, 07:39:07 AM
I am preparing a links page ( as you may have notice within the left menus). I just get in contact with people to exchange links. If you have any suggestions eith usefull links that i can exchange links, send me an email with these,
Title: Re: Motors
Post by: spic0m on March 14, 2008, 00:57:45 AM
Ok, i got another one for you.
How you can tell servo or stepper motors from the connection? Dull question and i can find it elsewere also but i like the way you explain it. (ok i'm getting paid by the guy to tell good things about him)  ;D
Title: Re: Motors
Post by: kam on March 14, 2008, 14:18:40 PM
!
A servo will have an encoder. A stepper will have 3 or 4 or 6 wires and no encoder and when you try to rotate it it will usually make a characteristic 'CLICK' thing. For example a stepper with 60 division will make 60 clicks per rotation  :P
Title: Re: Motors
Post by: Mosquito on March 15, 2008, 00:21:53 AM
This click is not always there! Some does no 'click' thing.
Title: Re: Motors
Post by: kam on March 16, 2008, 23:03:17 PM
really? i have never seen one clickless  :P
Title: Re: Motors
Post by: spic0m on March 18, 2008, 22:01:50 PM
Lol, stupid question indeed.  :(  :(
Title: Re: Motors
Post by: kam on March 19, 2008, 18:27:52 PM
You should know that already. You are a CNC technician!  :P
Title: Re: Motors
Post by: spic0m on March 19, 2008, 21:16:25 PM
yep but a noob one also, i practise the proffesion for one year only and the guy training me is leaving now, bastard!  ;D  ;D  ;D