Power Factor Correction for a small 60W AC Induction motor

[Tom.G]

Post 49, above:

Lsecondary = N²secondary X Konstant
knowing Nsecondary = Nprimary X 55/220 ?

Looks like a Square got dropped. I get 0.5H.

L_PRI = 8H
L is proportional to turns²
220/55 = 4 (turns ratio)
4² = 16
8H/16 = 0.5H

 

[jim hardy]

Tom's right of course, my mistake, haste makes waste... Thanks Tom !Look at that inductance equation.
A gap in the magnetic path adds a section of l_ength with term μ of only 1 instead of the few thousand that's typical of transformer steel.
So it knocks inductance down smartly.
If you can find a transformer with say a winding good for 48volts at 3 amps
and add to it an air gap
that should do.
Sometimes transformers that look like this

have underneath that sheet metal wrapper a core that looks like this,

http://www.rfcafe.com/references/po...nsformer-october-1960-popular-electronics.htm
(an interesting little article there, by the way)

you can see how easy it would be to place a thin spacer between the E and I shaped pieces and measure resulting inductance change..

You could wind your own coil, too.

old jim

 

[DjMadness]

Dear old Jim,

Your references, and explanations are vociferous!

Let me ask you at the moment about a switch, driven by PIC, that connects/disconnects caps according to code.

Popular one, is about Open-Relay Switch, but it is cored on Relay, that in turn have mechanical moving part.

I want to get rid of motion in switching, and referring to a solid-state device. the ULN2003 is a solid-state device, but its problem is that it doesn't connect load at full cycle.

What I want is a solid device, functions just like an open-relay without moving parts.

Any suggestions?

Following is a schematic for open-relay switch:

 

[jim hardy]

you're after a "solid state relay"

there are thousands to choose from
http://www.crydom.com/en/tech/newsletters/solid statements - ssrs switching types.pdf

 

[jim hardy]

Your references, and explanations are vociferous!

Webster
Simple Definition of vociferous
: expressing feelings or opinions in a very loud or forceful way : expressed in a very loud or forceful way

I've been called worse...

when you read that Crydom link
look at the 'zero crossing' variety of SSR's. They'll be gentle on your caps.

 

[DjMadness]

Dear old Jim,

It was a metaphor or equivalent.

Please tell me how to add images via private messaging. <Beside adding image URL, and if having image on the hard disk>

Thank you