EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Suggestions => Topic started by: uranium235 on June 16, 2010, 04:34:35 pm

Title: power saver device
Post by: uranium235 on June 16, 2010, 04:34:35 pm
i recently read about this in a local forum (also an engineering forum) so i decided suggest

this to have a video. how this thing works and i think there are alot of people curious about the mystery of this device   ;)



http://www.yugatech.com/blog/wp-content/uploads/2009/01/power-saver-max.jpg
Title: Re: power saver device
Post by: Time on June 16, 2010, 05:02:24 pm
Some kind of intelligently controlled capacitive bank that removes large transients off mains in your house.  It probably works best in places with lots of flourescent lighting or inductive loading (crappy power factor).

Thats my guess, atleast.  Probably mostly a gimmick - or most effective in a place like the phillipines where the grid is more unstable because of population density.

update:

After reading a little, its tricking the meter by introducing a power factor correction so its not truely saving any power.
Title: Re: power saver device
Post by: uranium235 on June 16, 2010, 05:15:55 pm
Some kind of intelligently controlled capacitive bank that removes large transients off mains in your house.  It probably works best in places with lots of flourescent lighting or inductive loading (crappy power factor).

Thats my guess, atleast.  Probably mostly a gimmick - or most effective in a place like the phillipines where the grid is more unstable because of population density.

update:

After reading a little, its tricking the meter by introducing a power factor correction so its not truely saving any power.
so if the power is stable that device is useless and so a good profit for the company who make crappy devices ;D
Title: Re: power saver device
Post by: cybergibbons on June 16, 2010, 07:40:03 pm
These are a waste of time and money.

The only things in the UK that you could have that would create a massive inductive load are:
* Old ballast fluorescent lights (and a lot of them!)
* Old fridge compressors

So, if you have these, it could improve your power factor.

But the meter doesn't care anyway - it will measure real power... on one assumption - that the power factor is approximately 1.

If you really, really try, you can push the power factor so far that the meter will under-read.

However, a lot of them are full of rubbish anyway:
http://www.bigclive.com/power.htm
Title: Re: power saver device
Post by: uranium235 on June 17, 2010, 07:41:23 am
so it will depend on how many inductive loads you have?
Title: Re: power saver device
Post by: cybergibbons on June 17, 2010, 08:16:54 am
Well, on the proviso that:
a) The device you have bought actually works (i.e. isn't one of the ones on the site I linked to)
b) The inductive loads don't already have some form of power factor correction (most ballasts are electronic, and most motors in the home are corrected)
c) You don't want to save any money, as the device costs you, and even if it corrects the power factor, you weren't paying for it in the first instance.
Title: Re: power saver device
Post by: alm on June 17, 2010, 08:17:48 am
Not really (if it's indeed a device to correct the power factor, and not an empty box). Consumers are only billed for real power (the power you can actually use to heat/turn/etc something), not apparent power (which is basically real power + reactive power). Commercial costumers (eg. industries) are also billed for reactive power, so they often have large capacitor banks to compensate for inductive loads. Reactive power can't be converted to energy (which is why it's not real), but the resistance of the copper wires in the distribution network does cause losses (I2R), so it does cost the power company money.
Title: Re: power saver device
Post by: NiHaoMike on June 19, 2010, 05:23:40 am
If you can find a source of free or very cheap motor run capacitors (broken appliances are one good source), make your own. If it works, great. If it doesn't, you'll have some nice capacitors to use for various projects.