Creating your own current probe for Dewesoft

Hello Dewesoft,

I have been a long-time Dewesoft user, but due to budget constraints, I need to use new Dent Meter CTR16A4U coils for current sensing in my project. These coils are also IP65 rated, which makes them an attractive option.

Here is the page for the coil: Dent Instruments Rogowski Coil

I noticed another forum page discussing a different current transformer: Dewesoft Accessories Forum. My coil has only two connectors, and I am wondering how to hook them up to the DB-9 connector I am receiving in December from Dewesoft.

Looking to use something like this for the DB-9-Connector for the current

and looking to use something like this for the voltage BU-2323-10-36-0

My Dewesoft configuration will include:

• 1 OBSIDIAN Rugged Waterproof Fanless Rack System
• 4-channel IOLITE Isolated HV Module
• 6-channel IOLITE 5TG Module
• 9 Thermocouple Type K Interface

Any help would be greatly appreciated.

Thank you,

Joe

Dear Joseph,

first, I would like to ask if you intend to use the coil with a dedicated amplifier/integrator or do you want it to connect directly to the device?

Usually, the Rogowsky coils come with an amplifier. For example:

You can try to connect your Rogowsky coil to the STG amplifier but I am not sure how it will ''behave''. If it has two wires the single-ended mode on an STG can be used:

The output is 131 mVAC/1000A @ 60 Hz or 109.2 mV/1000A @ 50 Hz

Please note that the scaling will have to be correctly adjusted.

Best regards.

Rok

Hi,

Apologies for the delayed response. I wanted to clarify your instructions to ensure I understand correctly. You're not certain if this will work, but you'd like me to attempt wiring a DB9 connector as follows:

• Brown wire to Pin 7 on the DB9 connector
• White wire to Pin 2 on the DB9 connector
• Shield to Pin 4 on the DB9 connector

Then, I should plug this into the 6-channel IOLITE 5TG module that will arrive in December.

Additionally, could you please explain the difference between STG and 5TG?

Thank you for your help,

Joe

Dear Joseph,

You're not certain if this will work, but you'd like me to attempt wiring a DB9 connector as follows:

• Brown wire to Pin 7 on the DB9 connector
• White wire to Pin 2 on the DB9 connector
• Shield to Pin 4 on the DB9 connector

Usually, the Rogowski Coils use a dedicated amplifier between the sensor and our device. You will see some readings of the signal, but some scaling will have to be done.

The first two connections are correct. The shield should not be connected to the Pin4, this is the GND pin of the amplifier. If you want to shield the sensor, connect the shield wire to the housing of the DSUB9 connector.

Additionally, could you please explain the difference between STG and 5TG?

I assume there was a typo. 5TG does not exist =)

Best regards.

Rok