well our prof said " a device that could strip off 20-50% of the electric bill". A legal one, of course!"

anyone can lend me a hand?

 

A switch that is spring-loaded to the "OFF" position

Seriously though - this is a school assignment; it should be in the Homework forum.

 

Could you please elaborate on the assignment you have been given?

hgmjr

 

Lets see, replacing incandescent lighting with CCFL, turning the refrigerator to the correct settings. If winter turning the thermostat to 65 and wear a sweater, if summer turn the AC up to 75 and try to use external ventilation when possible. Turn the temperature down to 125 on the hot water heater. Price out the cost effectiveness of high efficiency devices such as on demand water heaters, various cooling options, efficient refrigerator, if you have oil or gas upgrading those... etc

 

Hook up a very loud horn to sound when a power monitor detects rate of consumption exceeding 50% (or 80%) of last month's usage.

Or, more practically, make a study of where the power is being used throughout the day and month. Target any usage which seems wasteful.

 

There are devices being sold at the mall that states that it can strip off 30% of the electric bill. anyone of you had used this? or anyone have an idea what is inside of this device?

 

That's an interesting assertion - do they use magnets to align the electrons for higher efficiency, or a diode to cut half the current through the bulb filament?

Got a name for these wonderful devices? There is more than one mall, so not all of us have access to the devices you mention.

 

Well, it is marked chinese for god's sake.. (im sorry, i cant give a brandname) and it has a led lights when it is turned ON.
It was bought in a local mall here in the philippines.
Does these devices uses a capacitor to correct the power rating of an appliance?

 

juniorece,

the device is actually a power factor correction device.
don't be dissapointed, but i can say it is bogus.
power factor correction is needed there, but we are not being charged for the reactive power.
the electric company's meter at our house is only measuring the true power, so the only one that gets benefit from this device is the electric company (and the manufacturer of the device itself of course ).

in marketing this device, the demonstration is using an amperemeter to measure current flowing through inductive loads such as neon lamps with inductive ballast, to show that the device really works. well it does. it's the reactive power it's compensating though.
using a home kwh meter would show no difference in using the device or not, because the meter already measures the true power, excluding the reactive one.

 

look at this device at: http://www.made-in-china.com/china-products/productviewKTrEVuQGTJZP/Power-Saver-FL-001-.html

this is the device i was talking 'bout.. hope anyone can help me find a schematic diagram of this or simply what is inside that device..

 

to be honest, other than a capacitor (or capacitor banks with a microcontroller), i don't know what is inside or how this device works.
if you happen to get a hold at one, and manage to learn how it works as it claimed, please tell us here at the forum.

if it does contain only capacitors or capacitor banks with microcontroller then it is bogus. maybe there is no customer satisfaction guarantee or no rules against false claim by manufacturers in the country.

 

It might not have anything inside.
It might have just a cheap capacitor inside.

Look at Power Factor in Google.

 

Dear rwmoekoe, I agree all of you said about "power saving device" but I just want you to read a page of Q&A link below and please reply your comments whether they are right or wrong
http://www.mega-power.net/mega_qa.html
Thanking in anticipation,

 

Dear htookyi,

The thread you replied to is 7 months old and the interest is quite lost.

The device touted by the link is utter rubbish.