Isolation Xr. V/s C.v.t.s ?

Hello all, for the protection of a telephone exchange, from voltage transient, spikes etc, which is more useful and applicable, an Isolation transformer or a constant voltage transformer (C.V.T.) ?

Automatic Cyclic 555(or Any Other) Timer Circuit Design Requested.

Hello, I am looking for a circuit for an automatic timer which can switch ON and OFF an A.C. of 2 tonnes every 15/30/60 minutes (user selectable). The circuit relay and components should be able to handle 10A current.

Energy Saving Via P.f. Control ?

First of all, thanks to Internet , thanks to the creator of this forum , thanks to god/LUCK for making me come here accidentally and lastly thanks (in anticipation) to all the tech.guys who can help me out with my quarry, which I know otherwise might have remained unsolved. (By the way, I am from India.)

I bought a ENERGY SAVER device for up to 15KW load, from China, made with some German technology. It's a sealed unit which may be having a capacitor for sure. Anyway, it claims to reduce electricity bills by 50%, besides of course our benefits like surge protection, stabilize electric current, reduce electrical heating, prolongs life of appliances and saves energy efficiently etc etc.

http://www.made-in-china.com/china-product...er-FL-001-.html

I tested it on various loads in parallel to the device ,with a clamp meter and got the following results :


1. Current drawn by fridge before = 1 amp. / After device in-parallel = 0.6 amp.(40%)
2. By tube light = 0.3 amp. / After = 0.1 amp. (66%)
3. Table fan = 0.5 amp. / After = 0.3 amp.(40%)
4. AC = reduction very less or not clear.

But it did not show any difference before or after on Washing machine, Air-cooler etc, which did intrigue me a bit but I thought it is because both already have a condenser attached to them. But the shocking part was when the current consumption by the sealing-fan, instead of decreasing (or at least even remaining constant), it in fact increased by 20% !!!

Now by this I am totally confused (and sad at my purchase, as I wished I would do a business of this).

Now my questions to the experienced guys here on this and related subject are :

1. Does this device not work on already condenser attached appliances ?
2. Why is there an increase in current consumption, by the sealing-fan ?
3. Is the massive reduction of current to fridge and tube light, is then only an eye-wash, as at the end all appliances will average out in terms of overall current consumption ?

[Because when I attach the clamp meter to the main meter's phase wire and switch all the various loads, I get only an average 15%-20% reduction at the most. However, when only the fridge is ON, I get a reduction of 35% at the meter too (is the rest 5%lost in the wires?).]

4. Most importantly, does the reduction of 40% in fridge, reduce the POWER CONSUMPTION at the meter by 40% ALSO ? i.e. will my bill DUE TO THE FRIDGE ALONE, reduce by 40% or is it all differ net. I mean CURRENT REDUCTION IS DIFFERENT, to the reduction of actual wattage ? OR will the device work to actually reduce my bills, even though it maybe an average of, say, 15-20% only ???

5. So, on what kind of domestic or industrial machines and appliances do such devices work ? So, that I can still think of a business with this otherwise fantastic device/technology (as far as the fridge and tube lights are concerned) ? Also, in industries P.F. correction is a known fact and required badly by the industry too. This is the first time (at least for India, that a device up to 15KW load has come-in for domestic loads, where the concept of power factor correction does not exist at all).

The device is sold here by making a false claim of 50% by showing the current reduction on a tube light alone. God only knows, what happens finally when all the load is switched ON ? I got this doubt more, as when sealing fan was ON, the current in fact increased !!!

So, kindly someone explain the above points raised by me. WILL IT BE MORALLY AND TECHNICALLY RIGHT TO SELL THIS DEVICE to others ? OR, will it at least reduce 15% ? OR none at all ? OR on "particular", inductive domestic/industrial loads only ? I am very confused, kindly help ? Do I have a really nice and new technology at hand or is it all a fake ? Although, in industries, PF correction is a big big issue.

Waiting for a detailed guidance by all aware guys here and once again, thanks in anticipation.