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Scheme for Electric power savers?

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rx5

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hello all.. :)

anyone got ideas/schems for such a device? they are advertised on cable TV shows and claim they could decrease power usage for power hungy appliances....

you just plug it in, and voila! power Wattage decreases.....



tnxxxx
 

Mate, you can advertise everything you wish as long as you can find gullible people who will buy this bullshit.... 8)
 

rx5 said:
hello all.. :)
anyone got ideas/schems for such a device? they are advertised on cable TV shows and claim they could decrease power usage for power hungy appliances....
you just plug it in, and voila! power Wattage decreases.....
tnxxxx
I saw this type of adv before. But if you read carefully, the adv usually states that "You can save energy up to 30% (as an example)". This is not real...
 

oh ic.... :lol: twas really to god to be true... :) anyways, go tany infos how this gadgets work? i mean is there an oscillator or somthing?? :)
 

There was a discussion on this board last year about this. NASA invented the idea. It is for machines where a motor runs most of the time without a load such as a drill press. The device is a PWM circuit that allows the motor to draw less current from the mains in the unloaded condition.

The high unloaded current has a big phase angle with the line voltage so the current does not result in heat or mechanical power, but does make IR losses in the transmission lines from the power generating plant.
 

Hello,


from What I remember in college,

The nature of our appliances at home is somewhat purely inductive, so the imaginary component is producing a big phase angle difference between the real power and the reactive power.

What the device do is (Simple capacitor with bleeder) will introduce a capacitive load and will try to cancel the big phase angle.

If you will imagine a triangle, real power is the base, while reactive power is the leg. the hypotenous (Sorry if I got it mis-spelled) is the power that we pay for in our bill. so the smaller the phase angle the lesser our bill.
 

rommelm said:
Hello,


from What I remember in college,

The nature of our appliances at home is somewhat purely inductive, so the imaginary component is producing a big phase angle difference between the real power and the reactive power.

What the device do is (Simple capacitor with bleeder) will introduce a capacitive load and will try to cancel the big phase angle.

If you will imagine a triangle, real power is the base, while reactive power is the leg. the hypotenous (Sorry if I got it mis-spelled) is the power that we pay for in our bill. so the smaller the phase angle the lesser our bill.

how do you propose to do that? i mean capacitor with bleeder... maybe "add" ?? an electronic switcher for that "capacitor withe bleeder" ?? :)
 

rommelm said:
Hello,
The nature of our appliances at home is somewhat purely inductive, so the imaginary component is producing a big phase angle difference between the real power and the reactive power.

What the device do is (Simple capacitor with bleeder) will introduce a capacitive load and will try to cancel the big phase angle.

If you will imagine a triangle, real power is the base, while reactive power is the leg. the hypotenous (Sorry if I got it mis-spelled) is the power that we pay for in our bill. so the smaller the phase angle the lesser our bill.

We also saw this device in our country. Then, I discussed with my lecturer (he's an expert in power harmonic). He told me that the device basically consisted of capacitor to improve the power factor. He agreed that the device could help to save electricity but the benefit, for home usage, was not significant because:
1) The inductive load at home was small compared to factory/industry.
2) The length of wiring at home was short (therefore I^2R loss is low or ignorable) compared to factory/industry.

If we still remember, electricity supply company wants the factory to install capacitor bank to improve the power factor (e.g. more than 0.8). If the power factor is low, the electricity supply company will lose $$$ due to higher I^2*R loss introduced by very very very long transmission lines.
 

oh ic.... so it means the circuit behind this power savers are just plain capacitors, right?? ceramic capacitors? or high value electrolytic caps?? care to give a value??
 

PIceX said:
oh ic.... so it means the circuit behind this power savers are just plain capacitors, right?? ceramic capacitors? or high value electrolytic caps?? care to give a value??

Capacitors across the power line have to be specially rated and the symbol X is used for them. Power factor correction by this method can cause more losses because of the circulating currents from the resonant circuit. In commercial instillations the power factor is never made higher than 0.8 to prevent this problem.

The losses from the circulating currents are paid for by the user since it is on their side of the utility meter.

This method is completely different than the NASA method wihch is adaptive in real time.
 

flatulent said:
Capacitors across the power line have to be specially rated and the symbol X is used for them. Power factor correction by this method can cause more losses because of the circulating currents from the resonant circuit. In commercial instillations the power factor is never made higher than 0.8 to prevent this problem.
Do you mean the commercial installation is from customer point of view? As far as I know, the power supply company will be more happy if the power factor is higher, isn't it?
 

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