Prepaid energy meter based on RFID(Needded some guidance)

[karesz]

Hi,
I think your problem is, that the output has "shorted" only until 100+/-2.5 msec (as specified) as "the output pulse", & these max 100 times in a hour if you have had 1KWh!
Anyway, you can go (I think) up to ca. 60A=12KWh, or good 1200 pulses pro hour ...
I remember so that you have a power-meter with 100 pulses/KWh= in a hour you will count max 100 pulses(shorts from output transistor), but you told me yesterday over 5 houres measuring time for a 1KWh, it means you have at 200W load, concrete its a 200Wh load, you have also only 20 pulses pro hour, in all 3 minutes (only)one pulse...
These means you must trigger the scope (eventually for "single events") & at some higher trigger levels, i.e. +2, volts, so will you not see these such mV noises(an open measurement input), but a right pulse if outs coming(with time scale of 50--200msec), 2V/div settings...
K.

 

[huntersouls]

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

ok i will try again tomorrow and stay few hour to check the output and thank alot for the advice

 

[karesz]

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


You must know, its to modell with a slower generator too:
Take a funktionsgenerator for that (or some other signal gen in range of some Hertzes maximum) with output pulse of +4..5Vpeak, set i.e. for 100 Hz, find "triggered" to + 2V on your scope & switch then for slower & more slower the Generator outputs & see that you have triggered screen (maybe you must adjust some on trigger or Hold Off), up to 1 Hz or if you can do with your generator, than less, i.e. 0.1Hz and so on.
After that you will/can see the seldome coming "KW output pulse" on the so "pre setted/prepared" scope..
Another possibility to check for output/KWh-pulses:
You have a microprocessor system, what works; contact/put "out pulse" to an (iterrupt/digital) input!...
K.

Added after 18 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?

OK,
I think the red is input signal from your scope & black is the GND(or reference), as conventional?
If so is, I would contact w. red the pulseout & w. black the ref (or GND),what I signed with minus polarity too...
Anyway, the colours arnt interesting if you makes every times same for GND and so on, only is more conventional to use black for GND/ref, & red or other colour for signals (even by batteries: black is GND/middle contact & red is positive & blue is negative if you have a double supplyed system)
To my pdf-file:
positive polarity ist the external battery or pwr supply +, than the GND or even negative is = the negative polarity of your external battery or power supply.
THESE negative polarity is identical with your reference for all measurements(called GND too), & is = GND on your oscilloscope for clear situations.
Its often better for clean measurements/scope-screens if you put a bigger electroliyics on the + & - poles on your test breadboard (100 uF or so)...