Prepaid energy meter based on RFID(Needded some guidance)

Status
Not open for further replies.
H

huntersouls

Junior Member level 3
Joined
Jun 24, 2008
Messages
29
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,528
Hi everyone i need help in how to get the pulse from 1-phase energy meter. I was planning to do a energy meter prepaid using RFID. My idea is to get the pulses from the energy meter using with an ic like ADE7757 to count the pulse from the energy panel and interface with pic16F877. By using RFID reader interface with the pic16F877
it will read the value on the RFID as reload prepaid card and show the value on LCD.
My problem is

1. How to extract the pulse from the energy panel, if i buy the mechanical energy meter.

2. Needed confirmation if i buy electronic type will there would provide the pulse and straight can be connected to the ADE chip. This the energy meter i would like buy but not sure about the output contact pulse.

3. Is the pic16F877 is suitable us in this project?

4. Is there another chi like ADE7757 that can be interface with pic?
 

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

Simple mechanical meters don't provide a pulse output. If it's an academic project, you can try with an optical sensor instead.
But an important requirement of meter design is to achieve a trustworthy recording of energy consumption, so it won't work
for a real design.

There are more manufacturers of energy metering chips. I think, they all offer a pulse respectively frequency output, because it's a
common requirement for calibration purposes.

It sounds like you want to use the ADE7757 as a pulse counter? I don't think, that it has a pulse input, because it does the
energy metering itself from voltage and current measurements. It's a replacement for the mechanical energy meter.
A pulse signal can be counted by the PIC directly, you won't need a ADE7757, if you have a meter with a pulse output.
 

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

Thank for replying, i quite understand what u mean there. I having problem how to extract the pulse from panel energy. Down there i the link which i would buy the energy panel with the reference.

Website link from RS Malaysia:
**broken link removed**
RS stock number:457-2874

Reference link:
1. www.binu.somee.com
2. http://www.8051projects.net/downloads134.html
3. **broken link removed** ... AT89S52%29

is it possible to get the pulse from the energy panel i choose there?
 

Hi,
Refer pls to page 2: "Opencollector Optocoupler output(SO): 1000i/KWh, Min 5V, max30V_25mA/100 Ohm, Pulse duration 50ms"
Also you have only the "SO" to find; becauso it hase practically only this one output ...
K.
 

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

Thank karesz, but on page 2 also given diagram on the panel energy seem like there is not connection to get the pulse at all. Do you have any idea?
 

Hii,
NO-sorry. This isnt so.
Your thing has 6 screws, but the datasheet has miserable quality of copy...
On the first page you can see too= Outputs are on SO+ & - (both arte on the top of these picture)...
Good progress!
K.
https://obrazki.elektroda.pl/8_1273592581.jpg
 
Re: Prepaid energy meter based on RFID(Needded some guidance

Thank karesz, from the picture u give i think it might possible can be done. So i will order this type of energy panel. Ok jumping to next step, i need make decision in picking which PIC i needed to interface. And i need to check what the meaning of 1000 imp/kwh. Cause PIC input usually in current and voltage type.
 

Hi,
because the data sheet tells us: "Opencollector Optocoupler output(SO): 1000i/KWh, Min 5V, max30V_25mA/100 Ohm, Pulse duration 50ms", I think you have no more to do as apply an Collektor resistor of i.e. 2K2 to +5V and you will have the ca. 50msec pulses to your PIC...
1000i/KW must mean, if you have in a hour 1KW consumed, your counter will indicate 1000 (hase became 1000 time 50 msec long/width pulses or steps during the referenced 1hour time)...
As I know a PIC-input (as normal digital logic) needs "only" an input level over logic threshold , means digital high/1 , what in +5V system must be over +2.1V & for low/zero less as ~+0.7V, also your pulse ist practically =<0.5V for Zero & >+2.5--+4V for High/1in +3.3or+5V systems.
Sorry, for selection a needed PIC I can tel lothing , its not my terrain.
K.
 

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

Thank karesz, i get what u said. I think any type of pic can be used. The next concern about this project is that i plan to apply this "SO" directly to pic and apply normal digital input to the pic, is there is possible it will burn out the pic? As u said
"Opencollector Optocoupler output(SO): 1000i/KWh, Min 5V, max30V_25mA/100 Ohm, Pulse duration 50ms" hence i assume that the input pulse will be min 5V. Is the assume i make is correct?
 

Hi,
These means; you must take a minimum 5V supply for these outputs pullup, and means too, that your PIC, as simplest realisation, has 5V supplying too.
If your PIC is at 3V3 supplyed >> your pullup is on 5V (minimum!) & you has to apply an attenuator down to ca. 3V pulse-peak between the SO & PIC ...
K.
 

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

Hi again, thank i think i might get the idea and try it later. Another problem occur on me , the energy panel i was planning to order seem like don't have any stock left hence need to change.

I planning to change the energy panel to this type.

Data sheet:
1. **broken link removed**

Availabilities website:
1.**broken link removed**

Problem is, i cant really see the how to connecting the pulse from this type is it the same way as previous energy panel which is screw-in type? Ha ha i cant really make sure of it.
 

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

huntersouls said:
...Problem is, i cant really see the how to connecting the pulse from this type is it the same way as previous energy panel which is screw-in type? Ha ha i cant really make sure of it.
Click to expand...
Hi H,
Dont worry; it has two small srews (I think M3, or M2.5) for the pulse outs & bigger ones for the mains wires (upto 4.5mm2)...
K.
BTW some other and similar products:
**broken link removed**
 

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

OK, thank karesz now i will start test on lcd for this two week first. I will update the further new once i get the energy meter and RFID equipment.
 

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

Hi karesz, i got the RFID equipment already from the website below.

https://www.cytron.com.my/viewProduct.php?pid=ICAoNyUJCyYgMycKBwcGNW9SQ7HIPaCsC1BG3eEpHEA=&store=

Now i try to interface the RFID and still waiting for the energy panel. Problem is that i plan to interface the RFID reader with computer but from the picture the provide seem like need to cut out the R232 to do so......... any idea?

Is it possible to cut one head of the RFID reader and use it?

http://www.cytron.com.my/viewProduct.php?pid=NjgYAygpDR8wIAMYGg0OKzqdLhpEtG141eiy!!!!!YLyX5s=
 

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

Hi is me again, just wondering got any idea or brief idea how to program the pic to count the pulse sent by the panel energy?
 

Hi Huntersouls,
Im sorry, but I can not help you in PIC (& other) programming_Im a fully analog soul...
K.
 

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

Ha ha i understand is ok, since u are analog soul would u mind to help me on relay?
Cause i planning to use the relay to cutoff the direct supply when the user credit is used up. I was thinking if i use relay interface the PIC to cutoff the direct supply, for example if credit reach to zero the pic will give high logic to the relay to cut off while when it is reloaded then low logic to the relay connected back to the direct power. Is this idea be possible apply on this situation?
 

Hi,
I think its possible, but better to make with a semiconductor pwr switcher, is than your micro simpler to interface to the switcher too, but if you have KWs to switch, its of course with a relay more practicable_even if life cycle isnot endless...
Think pls on possible manipulations too!
If somebody take very-very strong magnet or ESD disturber; will eventually stop/overwrite your controll signal, or falsh control your system... ITS A REALLY IMPORTANT ASPECT by ENERGYMETER DEVELOPMENTS!
I worked some time ago for an international consern, the meters are most complicated as you can think it because IT NEED thes and those & x-time more PROTECTIONS in HW & SW!! Power piratery is a big busines :-(...
K.
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…