Connecting pulse sensor to lower voltage DAQ

[searme]

Hello there!

Simple question, I have energy meters like those:

Compteur d'énergie monophasé 45 A implusions

EM145PU - compteur d'énergie monophasé 45 A à impulsions Pour visualiser la consommation d'énergie active de tous les appareils électriques...

www.zelec.fr

this one is on a french website, but the operation is simple. This one in particular uses an optocoupler 27 Vdc for the pulses, but what is the voltage output? is it really 27 V pulses? How do i know if it's safe to plug in a low voltage data acquisition card?

For example this meter doesn't specify anything on how the voltage of the pulses works...

http://docdif.fr.grpleg.com/general/MEDIAGRP/NP-FT-GT/F01689EN-00.pdf

I am kind of lost.

thanks in advance for your help.

 

[ElectroChem]

As far as I can tell, that pulse output is an opto-coupled transistor, so it doesn't actually output any voltage itself. Rather, it switches a DC signal of your choice, with a max voltage of 27v and a max current of 24mA. The transistor junction is polarised, so it only works in one DC orientation hence the +/- rather than just 13/14 terminal labels.

 

[searme]

Hey, thanks for the answer, seems logical. But if i take the second meter that i linked, i've looked into it, in fact, it refers to a Uimp (Impulse voltage) varying from 12 to 27 V. even though it doesn't "output" any "voltage" i would still fry an arduino or raspberry for example...?

 

[ElectroChem]

Hey, thanks for the answer, seems logical. But if i take the second meter that i linked, i've looked into it, in fact, it refers to a Uimp (Impulse voltage) varying from 12 to 27 V. even though it doesn't "output" any "voltage" i would still fry an arduino or raspberry for example...?

I think those work at lower voltages like 3.3 or 5V yes? DIN meters like those are more often connected to PLC inputs that operate at 24V. I think it will likely work, but the lower voltage may not be enough to pass the transistor.

Where are you looking at installing it? You've posted in the Auto Electrical forum but cars don't normally have 230VAC running around for this meter to measure.

 

[searme]

Oh i thought this section was referring to auto=automatism (PLC, micro controllers...)
Anyway, it's for solar inverters, sometimes, they can't communicate in RS485 so i need to install a meter for monitoring purposes, but why buy a PLC worth a couple hundreds to monitor a meter that costs 10x less :/
Guess i need to search for another solution.

 

[ElectroChem]

There are definitely meters like that one that have an RS-485 interface. Ali-express is full of them, if you want reputable brands I'm sure an electrical supply store could advise you.

 

[searme]

There are definitely meters like that one that have an RS-485 interface. Ali-express is full of them, if you want reputable brands I'm sure an electrical supply store could advise you.

I will look into it, they don't seem that expensive, I still have a couple of the ones linked though... but I surely didn't think about just replacing them with RS485 meters!
Thanks a lot for you help!