hi,
The current transformer will output 'ac', you need to use a precision rectifier to convert the 'ac' signal to 'dc', then smooth this dc before its sampled by the adc.
Do you follow OK.?
EDIT: like this.
Can I buy a ready assembled one that meets the requirements off the shelf?
it is going to take me months to assemble one of those.
The sensor has two wires so this means that I have to plug two wires in and get one out.
One wire is connected to 0V
The out signal will then be connected to my ADC.
Please excuse my lack of understanding I am new to all this and I am trying to make some sense of what I need to do to interface the two devices. I can do the coding part but not the hardware side of it.
Many thanks for your time and efforts
I think the clamp-on sensor must be clamped around only a single wire in a power cable because if clamped around both wires then the signal is cancelled.
Here is the one that can deal with 3 cores:
https://www.tequipment.net/MeggerMMC850.html
In my case I am not too bothered really, I just need to be able to read the sensor by interfacing it with an ADC device that supports 10 bits i.e. 1023 integers (Up to 3 volts max).
As Eric pointed out to me I need a rectifier and then to smooth the signal, and he pointed me to the AD736 IC which seems to be the one I need, however I am just a bit confused as to which version shall I buy, exact connection details and whether I still need to condition my signal any further before interfacing with the ADC.
Many thanks.
hi,
The only difference between the two versions is one is surface mount and the other is DIP.
I would suggest a DIP version as you are experimenting, it will plug into your project board.
Read and understand the AD736 datasheet.
Get the ic working in the project board, examine the output from the AD736 then decide if extra conditioning is required.
What exactly are you doing with this project.? I know it measures 'ac' current in a mains line.!
But, why and how are you going to display the current.?
Eric,
The spot uses ADT711 IC.
I am also looking for the bits that simplify the connectivity with the sunspot. I am not sure if there any better place than Maplin or Farnell.
I am looking for the pcb socket one which should give me 0.025" pins to plug the female wires into. (do not know where I can find them in the UK.)
Regards
Charbel
hi,
One of the standard pitches is 0.1inch.
The leads you have posted have sockets, you say you want sockets for the pcb.???
I'll look at the ADT711.
Why have you chosen to go the SPOT route.?
hi,
Look at these pcb pin connectors, you can also buy the mating socket inserts.
https://uk.farnell.com/1554030/connectors/product.us0?sku=tyco-electronics-amp-5103308-7
https://uk.farnell.com/9730990/connectors/product.us0?sku=molex-22-04-1101
EDIT:
Do you plan to use all 8 adc channels and the tempr channel.?
Thanks I will look into these.
However I am not so sure where I should connect my sensor and wires to exactly. I have a vague idea, but I do not want to damage the IC.
I am assuming I will then take the output and plug it into one of the ADC slots on the spot edemoboard.
Any other tips will be very much appreciated.
Look at page 13 of 20 of the AD736 datasheet for the 'ac' coupled application examples.
Have you already bought the ADT7411, if not, look at the MCP3202 adc [spi/i2c] Farnell.
The spot comes with eDemoBoard that is already using the ADT7411 and provides for the ADC input to the spot, it has 6 input A0-A3 and A4 & A5 I think.
Checking page 13 out confuses the hell out of me.
Since my sensor is producing AC I presume it will have to be either Figure 21 or 23.
I will put my money on Figure 23.
I will assume that my sensor will be connected to pin 1 & 2.
+3V to pin 7.
GND to 4
6 is my output.
Just to confirm the DC output will range from 0 to 1.7 based on 2.8 V input right as per the diagram shown?
hi,
As I read it, pin 1, using a series capacitor for one sensor wire and
pin2 for the other.[0V]
Pin7 +3V
Pin4 -3.4V
Pin 6 output.
What type is your current transformer.?
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