We have voltage and current measurement equipment, but the display module does not work. So we want to use the Photon to make these measurements, does anyone have any idea how to work it?
It’s not clear to me what do you want to do ? do you want connect this clamps directly to photon ? or do you want interact somehow with digital interface of this meter ?
which kind of AC parms you would like to monitor ?
I’ll say no you can’t connect this clamps directly to photon as
you are limited by 12Bit AD resolution which gives you 0.8mV per unit (3300/4096) as long as this can be done with external 16Bit AD conv. which will gave you resolution of ~0.05mV per unit (3300/65535) which give you ~142mA per unit (0.35/0.05 =7 → 1000/7) but this is just for clamps, current measurements what about voltage ? and here is a big big NO NO NO ! you can’t measure AC voltage which amplitude is higher than 3V3 it’s physically not possible and is DANGERUS !!! when you deal with voltage higher then 24V you have to be really really carefully !
So theoretically you can use some external AD and get current but just with current you can’t calculate nothing e.g. Power, Power factor etc.
different story when the manufacturer provide information how to deal with their digital interface, as the display is dead you will have to ask them about full implementation of the communication I mean you have to interact with it in both side to set measurements (->) parameters and to get results (<-)
I want to amplify what @dreamER said above: this is challenging engineering problem and if you don’t have a good amount of experience building high-current and particularly high-voltage measuring equipment, you should not attempt to do this. It is just too dangerous!
Hi @JesusSoto96 -
That said, I have done a couple of current sensors and control (soft start with phase shifting), nothing close to 1kA, only up to 200A three phase.
Allegro has some nice sensors that might be able to get you started, (inline and busbar application) but you really need to think long and hard about what exactly you expect from this. Looking at your clamp rated at 1kA and 600V I can only assume the amount of power (W) you will be measuring will be substantial. Designing PCB for that purpose is challenging and requires a lot of detail, attention, careful planning and a TON of research unless of course you are familiar with hight current design. You can use non invasive off-board clamps that will make it a lot safer, but I have not seen ones rated at these specs that are logic level - I might be wrong.
The other VERY important consideration would be inrush current (which can be up to 6x your nominal current) and you would have to know the pulse duration of this inrush current. Then design you board and spect components to withstand this. Further you will have to consider the KA rating as well. At some point you need to consider whether it is not better (safer) to buy something tried and tested. For me that usually comes into play when lives are at stake
There are some manufacturers that is willing to assist with high current PCB design, but it will most certainly cost quite a bit.
Good luck and TAKE CARE!
I don’t like to mention my failures but maybe this warrants it
Attached is a photo of a PCB designed to withstand at least twice the requirement stipulated by the client. The client however failed to mention that they have a soft starter downstream effectively prolonging the inrush current from 20us to 20s!
This is what happened at 240V and 78A with inductive load… still a long way from 1000A!!
Again, please be careful!
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