hi, can anyone help me know how an electric meter can be slowed down using any remote sensing device? also can any one send me a circuit of how a crystal oscillator works inside an electric meter ?and how can one disturbs its frequency? and

can there be power theft by disturbing harmonics of three phase supply?

kindly try to send solutions if u know? thanks

i don't know what is it but this is very simple power meter. how about tehe secure of this power?

While many commenters are correctly concerned about power factor (phase) there is another even more complex consideration that if ignored results in serious errors: RMS conversion. Again, except for resistive loads, many AC loads can have very odd current waveforms that must be converted to their true RMS values.

There seems to be considerable confusion among the readers about power, energy, and power factor. The circuit shown will measure apparent power, or VA only. It will not read real or true power (watts) unless the load is resistive and the current is in phase with the voltage. For loads that have both an R and X component, the circuit would need to resolve the effect of phase angle. That is why the antique power meters had both current and voltage connections. Utility company mechanical kilowatt-hour meters resolve the phase angle mechanically by the way the motor is constructed with two sets of windings determining the torque on the disk. Kilowatt-hours are a measurement of energy, not power. If you know the power, just multiply it by the time the power is on to get kilowatt-hours.

It's very easy to slow down a power meter. I'm surprised all these engineers haven't mentioned it yet actually. You need to get a special tool though. It's pretty big, but not that expensive. Called a sledgehammer.

Good luck with it!

Z

good

im looking for the circuit diagram of an eletronic prepaid energy meter

im looking for the circuit diagram of an eletronic prepaid energy meter

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Super Prabakaran

im looking for a circuit which can measure the power factor....can anyone suggest me any circuit

I need some kind of Indicator(LED?)that lights up when my Solar System is pushing back more than I use at the Moment,my Power Co installed digi Meters,that CHARGE you for the Power I push back!

hi can usay me how prepaid energy meter work &which is best controoler for design thanks

i need some circuits for 12-48 v dc or ac input and 15 v Dc output if you can help me thankfull

let us c what u have done . Show the progress. Give ur college,university details

hi there pls help on my research work: how prepaid electric meter works?

Hey, if you're a final year engineering student and you can't convert power in KWH, nor get datasheets on your own, you should spend the time to get the routine down as this is not an unusual thing. What're you going to do when someone wants to pay you for the work? Can't keep being handed answers forever, that's what your education was supposed to do for you.

Hello Guy I'm a final yr student in Electrical Eng'g. I propose Digital KWH Meter Design for my project but I can't get the reading material for it. so pls help me how i can design it using a microcontroller for remote control.

urs

hi, i am a final year student of eng. iam going to build a prepaid digital energy meter but i have no idea how to convert power in KWH units. plese send me the information how to build that with HT1380 and 8051.

Slow down a meter? Well as a matter of fact, you can do this with a simple single transistor circuit. Simply pulse a ferrite rod (find that inside an AM radio) at high frequency and hold the end of the rod near the aluminum disk. Better still, thunp the meter around 3 hz quite hard. It will stop and you will get a sore hand.

Seems to me that D2 will short out the negative half of the sine wave. You can't connect a diode across a transformer secondary like that I don' think.

Very Simple and nice kwh meter circuit

How can the digital electricity meter be slow down using an external device ? Is there any circuit or socket like thing that can be fixed into the power plug to slow down the electricity meters?

HY!!

????? ?????(hellove people Howe are you?^) I'm engeneer from Ukraine Do you know thi country)

nice circut, i want to ask if any1 can help to make integrate circut to measure the power factor ?

hi, i am a final year student of eng. iam going to build a prepaid digital energy meter but i have no idea how to convert power in KWH units. plese send me the information how to build that with ADC804 and 8051.

"How can the digital electricity meter be slow down using an external device ?"

This is easy. Get a big generator, put some fuel in it, and hook it up to your house's power lines. Running the generator will supply power to your appliances, and any left over will go back to the power company, and actually turn the meter backwards! This will save you lots of money on your power bill. (However, it'll also cost you even more money in gasoline.)

Probably not the answer this moron was looking for, but "ask a dumb question..."

I need to learn how to make a digital power factor meter. Please if you know,let it know to me. Thanks very much.

we need the IC use full to measure MVAR & we need the complete circuitry with design such that i can procure the IC.name the ic & give details availability in india

Very Simple and nice circuit

How can the digital electricity meter be slow down using an external device ? Is there any circuit or socket like thing that can be fixed into the power plug to slow down the electricity meters?

Nice circuit. Assembled works fine!

I have once read about a circuit that could be built to slow down a power meter. Does anybody have any idea what this circuit may be called or when to find more information about it.

I need advice on how to design power factor angle meter.

fine

fine circuit

The circuit looks fine. there seems to be a problem with the understanding of what real and reactive power is.

If you want to measure reactive power get a Varmeter.

The person who wants the Fp of the circuit use a volt meter and a current meter to find the apparent power because this one gives the real power.

Obviously, an understanding on how an analog meter works is absent in all of the above comments. These meters work on a mechanical principle of Torqque and the instantaneous power which is directly related to the instantaneous torque.

Since there is a PM meter this means that the only dependant variable is the current through the moving coil within the PM field of the meter.

Current in an AC circuit rises to peak values and diminishes to zero many times a secong. the energy stored in the magnetic field of and inductor, or the plates of a capacitor, is returned to the source when the current changes direction.

If the current in an AC circuit is purely inductive (the instantaneous power which is directly related to the instantaneous torque) the torque is clockwise for 1/4 cycle and reverses for the next 1/4 cycle, the net torque is zero, ergo no movement on the meter.Where as real power is not returned to the source and its instantaneous power, hence torque is the average of the min and max of the torque and power hence the Average power or real power is recorded, because of a net torque being generated in the meter movemnet.

This is the whole problem with modern technology they don't teach the basics anymore. They give the student a digital meter and the first time they see a analog meter is in someone's basement and have no clue on how it works. Analog meters are work on an entirely differnt principle than digitals. Digitals generally use an 'algorythim' in order to measure power and current and the voltage.

Hi there! Can you please revise the circuit so that it will take into account the reactive component of the load? As you know, AC current is the vector sum of real current (produced by purely resistive load) and reactive current. Reactive current leads real current by 90 degrees if the load is capacitive and lags it by the same degrees if the load is inductive. About 95% of consumer's load is inductive. Thus, real or true power = (V)(I)(power factor) for a single-phase circuit. Power factor is the cosine of an angle between the voltage and current. The smaller is this angle, the closer is the cosine or power factor to unity, the less you pay for your electric bills.

May I request, if you could provide an schematic diagram for a power factor meter? Using a DSP IC would be much better since the circuit will contain less components. This DSP IC will measure the correct power factor even with the presence of harmonics in the line. Thanks.

Has it been built for the home consumer? By who? If not, it should be.

artical is excellent documented well and i will visit this for futher clarification

novice-like idea, but useful circuit

The circuit is at best an "AC Current" indicator. Power in AC circuits is the product of RMS voltage and current and POWER FACTOR.

wow, tiny circuit but useful to me

good circuit, really i searched it for so long

very simple and interesting

Article is incorrect -- the circuit is at best an "AC Current" indicator. Power in AC circuits is the product of RMS voltage and current and POWER FACTOR. The latter was never even mentioned in the article!

Very simple circuit,and useful for beginners

Good circuit, useful for many designs. Electronic Design should publish such simple DBs like this one.

While the circuit may appear to work from a novice point of view, one should be warned that true power is the product of E x I x Cos theta. Without taking into account the power factor, or phase angle, the wattage result can be drastically inaccurate. Therefore, the illustrated circuit will only be valid for purely resistive loads.