SMART METER DESIGN FOR MIDDLE END PEOPLE AT LOW COST

Dear Friends,

i have been looking for ADC Conversion Circuit, which will read the energy consumed in home and make some calculation,display on Lcd in local currency value.

this will helpful for Middle Class People to reduce their Electricity usage.

Single Phase Will be used For this Circuit

I am going to use PIC16F877A for this project with 16x2 LCD MODULE.

this meter will Display the Following Details,

1.Live usage in watts
2.Consumed TOTAL Usage from last reset in Rupees (INR)
3.Last One Day Usage(INR)

dude just for ur help i wanna tell u pic 16f877a can withstand a maximum voltage of 5 volts so u have to use a device to step down the voltage to 5 volts so i will suggest u to use ic 7805

Thank U for Your Kind reply.

Just Now i have Heard From another Friend that We can Use the "Current Transducer" to Measure the Single Phase Current .


Live Wire Means Single Phase AC Line.

I want to identify How much Current passed through My Meter

then i Can Calculate the KWH

A simple possible way to convert a mains voltage current to a low voltage measurable by a microcontroller ADC, is to use a small transformer, which you could wind by hand. (Kits for making transformers are available.)

This transformer will be inserted in series in the live wire of the mains supply.

The primary would be a few turns of ordinary mains insulated wire around a soft iron core, the secondary will have more turns of a much finer low voltage, low current wire. You may need to experiment to find the number of turns required to obtain the necessary level of output.

It will be a step-up transformer, as the primary will be using only a fraction of a volt of the mains supply, but you will want up to 5 volts to go to the ADC at the maximum mains current taken.

The output from this transformer would be rectified by diodes to provide a DC voltage, levelled by a capacitor, with a resistor to discharge the capacitor when the current falls.

If anyone knows the appropriate formulas for tranformer design, or a suitable commercially available transformer, please share the info.

I am am only a technician, if any engineers can provide improvements, they are welcome.

Hi Immanuvel

I think what you want is here on this page
http://scienceshareware.com/how-to-measure-AC-DC-current-with-a-hall-effect-clamp-.htm

Calculations are here at this page for your final readout using the ADC module on bourd the 16F877a

http://www.rapidtables.com/convert/electric/Amp_to_kW.htm

Also have a look at this as an improvement to your circuit using op amps

http://circuitelec.blogspot.co.uk/2009/12/ac-line-current-detector-circuit.html

Hope this helps you

Mark www.harrington.force9.co.uk

Thanks Mark,

the first Link will be useful but the cost of the Current Sensor is Higher

i Have to find the Low Cost transducer Available in india or Some other alternative

Thank u Frank

If any ready made available device will be easy to Implement this Meter

Welcome Just as another point further of interest what you can do is this : - From your 16F877A provide a serial port link or if you like attach a Ethernet module or modem then what you can do is set up a database on a remote server to send all your monthly bills to your electric company on

In other words at the end of each month The electric company dials into your module or sends a packet message via TCP/ IP and retrieves all your customers information to automatically bill them Saves having to send a meter man out to manually check your meters Quite a good idea don’t you think ??

Totla cost to energy firm one phone call , couple of microseconds as opposed to I man 8 hours per day at £25.00 per hour

I bet the Transco whished they listend to me now hmm ??

In fact consider if you will just how much money they could save and what this would do to revolutionize Gas meters and electric meters Also consider that due to this they could also now refrain from massive increases in energy bills and what that would mean for the Old age pensioner What a massive saving of wasted man hours simply by converting the original meters to digital and also providing an Ethernet link or telephone modem link or for that matter even a wifi link for gaining each and every persons gas and electric readings

Not even difficult to do !! Why so long you ask Good question I, also question this as well since this was suggested by myself nearly 5 to 8 years ago and still no one has even given this any interest You tell me !!

Finally whats the big bonus in doing this then you ask Petrol , man hours , cars , expenses "Massive savings" and What else ?? cant fiddle the metres anymore Notifies the Gas company electric company as soon as an attempt is made to fiddle the meter In fact you could even use this incorperated into your project as well

Not sure about the UK but in the US AMI, or automated metering infrastructure, is highly deployed. The methods are utility specific with some using wireless and some using a carrier over the power lines. No one is using 3rd party copper lines (phone, ethernet) to my knowledge.

My personal opinion about the deployment schduling has to due with the way regulated utilities fund projects and recoup investments. In a nutshell, it is easier (legally and financially) to keep paying meter readers as an ongoing expense rather than investing millions upfront and recouping the equipment cost over time. Wide scale deployment did not occur until the federal government mandated deployment and provided partial funding.

The primary goal is to encourage different consumption patterns via flexible energy pricing. i.e higher prices during peak demand. Other benefits such as consumers being able to access their consumption data is a side benefit. I have not seen any detailed analysis but I don't think AMI will be cheaper for consumers than manual meter readers at a micro level. At a macro level, one could argue that forcing consumption patterns to allow the electric system to be operated with a more constant load will allow the system to run closer to peak capacity without building aditional power plants, therefore lowering consumer costs in the long run.

Hi Todd the answer to this is no they don’t

Hence why we have such high energy bills Most of the costing of course is in the labor

In fact most meters in the UK to all intensive purposes are way out of date I’m surprised that the Meter man , and this will make you laugh , “walks into the premises and punches the figures into handheld and then faxes them to their head office via modem when he gets home or he puts memory card into the handheld and takes that to the office “

A simple usb port on the side with an ip address , a wi fi link and you wouldn’t get human error at all

In fact you could also argue that wasted man hours are spent on the phone when the bill is estimated incorrectly "Here we think accounts departments, Pro or what they term as human relations

You might also debate that if done with a small area to start with the savings would be incredible and so the Investment negligible with a view to overall costs You might even choose a GPRS Modem with an initial setup fee to the customer one off and simply part of your bill is the top up amount Also negligible if we consider that an sms message costs 0.20 pence


The public telephone systems in the UK if anyone still uses these are used if you don’t mind to punch in the credit card details over a public telephone link “That’s DTMF tones over a public link “

Yet no one including the banks of England have ever regarded this as a complete nonsense when it comes to security and fraud over the telephone You would only have to have to put DTMF decoder coupled to the line and a VOX transmitter so that in days you would certainly have all details of the consumer , plus dates of birth, plus credit card details


To make this even better they then decide again if you don’t mind to sms your bank statements to your mobile phone uh , “ Data not encrypted at all “ and then ask you for your password alternating on each occasion over and audible link i.e the microphone

Despite pointing this out to the banks of England as being highly dangerous because of the fact that you can access person personified mobile phones via Bluetooth , “serial over Bluetooth “ and you can dump all contacts and bank statements to any PC or other mobile using simple hays AT command set

This then means that anyone whishing to supposedly transfer a file to you via Bluetooth you being unaware of this whilst they issue Hays commands to dump text messages , also your recent bank statements call other numbers and extract details from your mobile phone

Having done so they then follow you to a cash point and hold you to ransom

They didn’t seem to take much notice of this when I pointed this out to them

The real answer to this problem would have been to insert a smart card holder on the underside of your telephone or an adaptor for your mobile phone such that you don’t have to type in any details also so that any data sent could be encrypted and access could have been re written to the memory chip on the credit card using rolling code algorithm

The Banks of course have failed to answer to this still and to this date 27th April 2012 also I might add major credit card companies "Still no answer "

All I can say to this one is "Thank god for people who can hack otherwise we never ever find out this would we ?"

But its an certainly interesting discussion


Thank you for your comments
Mark Harrington

www.harrington.force9.co.uk

Hi Mark ,

It is a very good idea.but in india its highly impossible because we are getting the energy from
Goverment Sector. So,i have to go with this option only.Here we are still using analog meters at home.
for the past 2 yrs only they are switch to Digital Meter if we want to with Your idea atleast it will take 15 yrs from govt side.


I have selected current Sensor from honeywell this model CSLH3A45 OR CSLT6B100 CAN U TELL ME
the connection procedure .


Thanks

FYI: there is already such a product on the market -- the Kill-a-Watt meter:

http://www.p3international.com/products/special/p4400/p4400-ce.html

Not sure if there's a version for your country, though.

I thought you would like this and find this interesting

Best of luck



Mark Harrington