Measurement for device with higher voltage


#1

Hello,

Would you please provide me more information about measurement for device with >5v voltage? For example, 12v device.

Thanks


#2

Hello

Otii is only designed for up to 5V. However, we do have customers with the same request.

One solution is to simply insert an isolated DC adapter or power supply in line with the Otii main terminal.

This would boost the voltage range, and you would get full benefit of the current measurement’s dynamic range.

You would not get the correct voltage and energy readings, as the Otii only sees its local voltage, but current measurements would be correct.

The limitations are the needed voltage ranges, please supply more details if you want to proceed with this solution.

If we assume four Alkaline batteries in series, running from 1.6V down to 0.9V each, in total 6.4V down to 3.6V, I then recommend using a 3V adapter, giving good performance for this voltage range.

It is important to use good quality DC adapter or power supply to avoid noise and regulation issues, and depending on needed current you might need an adapter to power the Otii as well.

This setup have been verified and is being used.

Hope it helps!

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#3

Hi, just going to hijack this thread because i have more questions. So if my intended voltage range is 0-7.2V, should i use a 7.2V power supply and then feed the otii through? and in this situation are we leaving the main power on the otii off and just reading the main current?

Thanks


#4

If you leave main power off on the Otii Arc you won’t be able to measure any current as the output relay is open.

The Main terminals has to output at least 0.5V. The maximum voltage output with only USB power in high accuracy mode will be 3.75V so to get a control range of 3.95 to 7.2V you would hook up a floating 3.45V power supply in series with the positive main terminal (remember the negative main terminal is grounded). By turning the main output off the voltage would be 0V as the output relay will physically interrupt the connection.


#5

Right I’ve got you. Thanks for the info, ill give this a go.