Capaciters

[Richard]

Hi,

I wonder if any of you could help me.

Capaciters. I have an idea what they are, but not what they are used for....Make sense?


I understand that they are like tempory batterys, storing charge, but how are they acually used in practice.

Today, we disasembled a Planer, and I noticed that it have a Capacitor wired in. Why would it have this just for running a motor?

Thanks in advance.

Richard

p.s. many more questions to come!

 

[TonyM58]

It would have this (assuming its a single phase motor) beccause its got two windings, a start winding and a run winding

these must be 'out of phase' to get a simulated rotating magnetic field (like in a three phase motor)

use the pneumonic CIVIL

c = capacitance and L = inductance

so in a capacitive circuit I (current) leads the voltage (or voltage lags the current depends which way you look at it)

so one one winding I & V are in phase, and the winding with the capacitor will be 'peaking' at a seperate time, giving effectively two seperate magnetic feields for the motors rotor to follow

most motors and machinery are inductive by nature, so in large installations, some motors are 'over excited' to become synchronous capacitors, thus bringing the current and voltage more into phase and reducing losses.

appreciate this is a VERY BRIEF explanation of a very large subject

hope this has helped

 

[markthespark]

JASUS Tony where do you keep all this info mate haha

 

[TonyM58]

JASUS Tony where do you keep all this info mate haha

Mark, seriously, sometimes i think a need a brain wipe, you know like on an 'etch-a-sketch'!!!

honestly, i have just spent a number of years educating people, guess some of it just sticks in there!!!

 

[Bane]

Am I missing something here??? Where's Tony's post? Same thing in another thread.

What you doing Luke?