Micro Power Factor Correction?

The cigar box devices are scams.

I am enclined to aggree whole heartedly with you , However, there have been miniturizations in most fields including "Capacitors" which seemed to make up the bulk of such correction devices.

Perhaps you could elaborate on the method of fraud being marketed by these scam artists. What exactly are they selling? are they claiming that a super capacitor the size of a pea replaces one the size of a suit case?

GF

http://michaelbluejay.com/electricity/powerfactor.html

http://www.sciencedaily.com/releases/2009/12/091217102304.htm

There are others (covered on CR4, just search for power factor scam). Many of these are products are misrepresentation scams (the product would work for an industrial site with lots of poorly loaded (low power factor) induction motors but not for a home with an almost purely resistive (high power factor) load). Others (like the small 'magic' box with no capacitors that alters the waveform with an inductor or magnet or such) are blatant scams.

Capacitors have reduced in size due to material improvements (such as super or Ultracapacitors which sacrifice voltage rating for energy storage and operate individually at DC only voltages up to commonly about 2.7V), but in the case of AC mains voltage rated capacitors suitable for power factor correction, not by much (due to physical laws and material limitations). A modern KVAR sized power factor correction capacitor is still a large bulky capacitor just as it was 50 years ago.

Capacitor arrays for Power Factor Correction are bigger when designed for higher power use. Due to non resistive loads (inductive and or capacitive) current and voltage are not in Phase. To correct this your array handles current too.

Space is expanding. I don't know for sure how this works. Ask Jorrie.

Firstly - I do know age of OP - when he says why things were huge in my days!!

I hope you are aware that Pulse width modulation techniques using solid state semiconductors like MOSFETs and IGBTs are being used now and tehy operate at high frequency - may be baout 50 to 60 KHz, unlike old time inductor and capacitors which were used to correct power factor- operating at 50 or 60 KHz only. This is teh real reason behind size reduction - unless you have soem thing else in mind- and then do let me know.

When I was in primary school, our projector (remember these?) broke down and a technician was called.The problem was a bad capacitor.Being the curious lad that I was, I asked what it was, what it did, etc.It was a 100 mfd.What does MFD mean?, I said.

"It means 1/1000 th of a farad. A 1 farad capacitor would be as big as this room"

Nowadays multifarad capacitors are no larger than a thick coin, due to progress in materials and manufacturing.

That's progress for ya.

I know there have been great advances on miniturization, however the dialectric strength needed to with stand 500 volts AC remains a barrier ,excuse the pun.

If capacitors could be miniturized for high voltage, would we not have seen the "disapearance" of the bulges on the sides and tops of single phase motors?

Would this new breed of capacitor not have been installed inside the frame of the motor for convenience and cost reduction?

GF