0-10Amp DC Transducer for GOLD plating bath?

Hi

I have a current project using an FX2N mitsubishi with an 8AD addon card.

I need to get into the plc the current from a 0-10Amp dc supply.

So far I am looking at these transducers

http://www.powertekuk.com/dcasensor.htm

Any one else got a pointer for me ?

Resolution and Accuracy is preferred rather than price.

The dc is from a thyrsitor fed transformer with full wave smoothed bridge.

The application is a Gold plating bath on a printed circuit board line using i believe Nickel (although i may be wrong here).

Specs are 8V dc max 0-10 Amps adjustable with a 0.01 amp resolution or better.

Oh and this is new to me so anyopne with expierence in this field is welcome to assist!!!

The full wave bridge is 'rectifying', not 'smoothing'. The thyristor control means you must have true RMS.
You can measure on the primary or secondary side of the transformer.
I'll assume 240 vac. The primary is about 0-500 mA. One example is [font=Verdana, Arial, Helvetica, sans-serif]OM9-31382AHD2 from Omega.com.

I checked your link. Powertek doesn't say very much about the CTHR module, but that's the one you need. The input for this module will be with a 'Shunt'. Look here to see a shunt example.

You could also do it on the secondary side of the transformer before the bridge, or after the bridge. At the secondary side, you'll be measuring the full 8 amps. On the primary side, you'll need to have a multiplier for conversion.

You could also do it after the bridge if you want - really doesn't matter where on the secondary side. The most important part is to make sure you have 'True RMS'. You need that even if you're measuring on the DC side.



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money no object? throw away that PSU and get something like Xantrex and enjoy...
it is a lab PSU, programmable, with nice displays, all goodies you want including analog I/Os...

Hi Dave,

Looks a bit 'clunky' especially having a separate transducer & signal conditioner.

I usually use Phoenix Contact for this type of thing, they do a compact DIN rail mounted device that should do the job...

Your best bet for accuracy and resolution is to use a shunt which is a high precision resistor wired in line with the DC output of the rectifier/power supply. Your shunt will produce a voltage drop (V=IR). If you want you can buy a voltage to 4-20 mA converter but it would be preferred to read the voltage directly.

This is typical measurement for power supplies / rectifiers in the plating and battery manufacturing industries.

Check with http://www.ohiosemitronics.com.

They manufacture a wide family of true RMS transducers which are specifically designed to work with the non-sinusoidal ouputs of SCR and Triac power supplies.

Current Transducers

CR Magnetics (www.crmagnetics.com) has a full line of hall effect current and voltage transducers that I have used with your choice of signal outputs (0-10 VDC or 4-20mA) that I have used in another application. Check their accuracy to see if it meets what you need. They have worked well for me.

What make power supply / rectifier are you using?

I have done the same thing you are doing a number of different ways and I have always found the the manufacturer of the particular rectifier / power supply that you are using almost always has an interface board (0-10v, 4-20ma, etc.) that works directly with thier SCR units.

From experience, this has always worked the best.

Chris

I know that Wago offers a 0 to 2 amp, 16 bit, 2 channel input module. They may offer something higher or be willing to customize what you are requesting. Otherwise, you are looking at a shunt or a two stage setup.