Voltage Measurement in Very Noisy Environment

R

Thread Starter

Roy Matson

Hi,

I need to find a number of DC Voltage transducers for a very noisy environment associated with a large DC to AC inverter described as "a Radio Station in a Box" The unit has a switching frequency between 4 & 20 kHz.

Ideally I would like a transducer that measures 0 - 150 VDC and transmits back to the control system via fiber optics. This would make it easier to protect the control system from the RFI

Does anybody have experience with such a transducer?

Thanks.
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There's no single transducer I'm aware of. Any signal conditioner vendor has an isolated 'high voltage' (it's all relative') DC-to-4-20mA module.

http://api-usa.com/pdf/api/api4380ghv3.pdf

As far as I know, conversion from analog to Fiber Optic (FO) is a separate function.

Weed Instrument (and I'm sure others) have a 4-20mA-to-FO 'transmit' modem and a mating 'receiver' modem (FO-to-4-20mA) for the other end. There's single or dual AI/AO models:

http://tinyurl.com/o9z5pps

or multiplexer/demuxers with multiple AI/AO modules. No programming, wired-in/wired-out.

http://tinyurl.com/mju8vea

If it's as electrically noisy as you report, you might pulling shielded TP leads to an area more conducive for typical DIN rail mount converters. Or make a Faraday cage?
 
R
David,

The Weed Instrument modules look like a good start.
The conversion from 0 - 10 Volts to fiber optical signal should be fairly easy to make noise free, the fiber optic cable will be ok but I have a hard time converting it back to an analog signal then re-convert it yet again back to Digital.

If I could go from a converter (Modbus Slave) daisy chained to other converters via fiber then back to a PLC Modbus Master with the PLC as Master that would be ideal.

I will certainly get in touch with Weed Instruments and let you know what I find out.

Thankyou for taking the time
Regards
Roy Matson

>There's no single transducer I'm aware of. Any signal

>If it's as electrically noisy as you report, you might
>pulling shielded TP leads to an area more conducive for
>typical DIN rail mount converters. Or make a Faraday cage?
 
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