Prepaid energy meter based on RFID(Needded some guidance)

[karesz]

Hali,
If you will make a product with switched mains voltage, than (in my opinion) you MUST HAVE EXACT SAFETY DATA over the relay(you must know it)_or must select another type!!
I dont no which contry are you from, the actual safety regulations are important to know for you!
For me is important to know, is it really a 230V relay, with enoiugh isolations/crepage distances!?
Is in your contry a mus (maybe is not) to have a so called "safety relay"(they have defined position after mains loss)?
In all cases I WOULD apply an ISOLATED DRIVER from your uP to the relays transistor_or even the RELAYS COIL MUST BE ON LOW(DC?) VOLTAGE, i.e. on the same as your uP!!
Shorter said: I believe that you need another relay to select...
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hi thx karesz for your advice but i still wondering if the relay connection is correct and the output is 230Vac. By the way i come from malaysia. I think i will speparate it from the uP just in case.

 

[karesz]

Also, the load is correct switced with your relay, but for me is the relays coil falsh on the mains voltage!!
It must be connected to a low voltage supply, maybe (or practically) to the supply of your micro!
So you dont need some isolation between relays control transistor & micro , but you need a good relay; I mean not a hyper miniature low voltage type!
In that case will be the isolation in the relay placed_ between contacts & driver coil...
That is than correct for the full worlds safety, so far I know
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Thx karesz, so far i not sure whether the relay can connected to Vac voltage. Actually the relay i use for as switch to cut off power to the load and pic as trigger the switch.

What if do like this:

https://i766.photobucket.com/albums/xx306/hunter1984/relay-1.jpg

Today i was doing a simple rectifier ac to dc voltage and end up the transfomer got a burn smell but still got the supply power i needed to supply pic, i cant figure out what the problem.

My transformer specification is a step down transformer from 230Vac to 12VAC then rectifier it to dc voltage.

https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0437.jpg

The connection from direct supply.

https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0432.jpg

To breadboard
https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0431.jpg

Here is my relay specification, i want to ask how much output voltage we can get from pic?

https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0429.jpg

Dont mind the relay connection on LED cause i just wan do some testing.


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[karesz]

Hali,
your transfomers primary with 0, 110 & 230V are only as 0V & 230V to connect to the mains!
Forget the black(110V wire); but do isolate it & connect never to your circuit or other points!

Maybe is your relay some similar one: http://www.chinacrst.com/crs t73 relay.html{
In all cases: you have a DC 5V relay!
It will be killed on AC 230V!!
Their coil is to your DC 5V to connect, not to AC 230V!!
Dont forget a diode parallel to the coil, with cathode on + supply & anode down, on the transistors collector/relay connection....
If your PIC is driven from 5V, it delivers similar outputs_sligthly lower as 5V if the loads are not illegal.
If you will switch a LED direct to i.e. 5V-maybe you will kill it, than you must limit the supply current with a serial resistor! so ca 330--470 Ohm can be real...

You must ask your distributor for a relay datasheet!
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

OK thx i understand already ^o^, i do some testing all part is working now

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Karesz need some help or the energy panel connection~~~
First at all is the connection which i put notice is correct?
Secondly Why i need connect 5V to 40V to the positive pulse output?

Hope u can help cause i not sure about the connection

https://i766.photobucket.com/albums/xx306/hunter1984/WiringDiagrams.jpg

 

[karesz]

Hi,
Where is description for first question pls?
Second subject: It has a potencial free(basically an optocouplers transistor) on Out Pulse (20/21) contacts.
Their need some supply between 5V up to max. 40V-extern!
Its a little bit spetial specification/drowing for me too..
And a serial restor/circuits input for setthe output current fore functioning, it must be less as 100mA!
Pls refer to fig.2-15 of attachements-link.
**broken link removed**
If question Nr1 is L1 in & L1 out:
You must the load (some equipment) feed through because you wish to measure some energy consuming from that...
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hi for the first question is over here

https://i766.photobucket.com/albums/xx306/hunter1984/WiringDiagrams.jpg

I dont get what u mean 100mA but what i understand is that if i want supply with external voltage does it mean i need supply it with 5V dc cause it wont be burn up my PIC and the for 100mA what i understand is that , the current from the output pulse isn't it?

 

[karesz]

hoi,
read the, from me, linked manual pls!!
It clearly describes what it means...
The output (a optocouplers transistor) can max 100 mA deliver, but you must not have a 100 mA.
You should/can use it (in my opinion) with only 5-10mA (a serial resistor of 2.2--4.7K) & 5V of course
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hihi thx karesz i done with hardware part already but i still cant get the pulse from oscilloscope >.<. I did supply 5V supply but no pulse.............

 

[karesz]

Hi,
Be care pls!
If you didnt apply some KOhm serial resistor: you have yet(practically 100%) a dead output transistor! :-(
You must have a current adjusting/limiting (or called working too) resistor for a supplyd /biased transistor...
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Will it got percentage to spoil the transistor if i didn't apply any?
I was having another problem as i don't have any equipment to can use a lot load to show the power used >.<.

Is this connection correct as i try today at lab no pulse give out >.<.

https://i766.photobucket.com/albums/xx306/hunter1984/scope.jpg

 

[karesz]

Hi,
its more conventional to change the battery/pwr supply & your resistor (battery + pole on Collector & -pole & resistorcommen=reference point, other resistor contact on Emitter-as another measuring point or pulse out), & referencing to the Emitter (as you maked), but important is to measure only on the resistor!
Because your system is floating; you can make it_measure only over the resistor_ not from emitter...
The above descripted connection makes no phase reversing or inverting to optocouplers inp(unknowed) input.
Otherwise if you need an inverted signal_ no problem: connect battery -pole to Emiter, these point is reference potential/output GND, & connect resistor to collector and the other resistor pole to battery plus pole: In these circuit is pulse out from collector to take, even GND/or reference potential at the Emitter.

Dont worry, you have an output transistor, of course, in the optocoupler in the "Power Meter Unit", but what you are writing-I didnt get it 100% .
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hi karesz,

Thank you for quick reply, on your advice i don't really quite to catch what are u trying to tell sorry as my understanding is not really good is it possible u describe in diagram?

Another problem that i encounter today is that i might be buy wrong panel meter as it is really hard to get even 1KWH~~~ now i still measuring the using of CPU+monitor usage around 5hours and till now haven't get 1kWH......what should i do ><

 

[karesz]

You dont have a vakuum cleaner or an iron, eventually a water heater?
Be care with the right KW-Meter model selection, than a washing mashine needs 1 KW or more ... (I remember so, that for these goal will it developed)
Clear, it is really better to have some resistance (or electrical/active) load, but you dont have it yet.
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hi again i being testing with cpu + monitor lolx it took around 5 hour to run up to 1KW. Thx for the pdf file i will test it again in lab

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Ermm that 5 hours just for measure the CPU + monitor usage power that i measure using the panel meter. My aim of this project is doing a prepaid reload the mcu and calculate the usage of user use and deduct the money through prepaid method, But seem it hardly to show 1KW would be possible to calculate the pulse and show on my lcd in term of watt instead kilowatt.

In Malaysia , the payment is done through how much unit kw is used by the user. Through my survey one house will only use 100kw per month hence it wont be possible to show that amount in short time as i don't have that heavy load.

 

[karesz]

Hey,
you can take a pulse generator too for testing your equipment_of course after that your PowerMeter Module verified is as original "KWh-pluse generator"...
K.

 

[huntersouls]

Re: Prepaid energy meter based on RFID(Needded some guidance

Hi ,

Today i was experiment the way u teach me but seem cant get the result yet.
I provide some picture to you see but not really clear.

https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0453.jpg
https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0452.jpg
https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0450.jpg
https://i766.photobucket.com/albums/xx306/hunter1984/CIMG0454.jpg

I think would it possible that since not enough load to generate 1KW so it wont produce any pulse?

Added after 24 minutes:

ok let said the oscilloscope got two cable red and black, the red cable connect to your measurement ref. while the black cable to ?? (ground or negative -5V). Is that connection correct?

Ok for the pdf connection you provide let said i use a cell battery the positive pole to the indicate place in your pdf while for the negative pole also same method. Do i need to connect external ground for it?