I need to find a signal converter that converts 4~20 mA to 0~200 mA

I have heard this converter at the first.

why use 0-200ma? its not standard porduct.

but not difficulty to build up by your self.

http://samplecode.rockwellautomation.com/idc/groups/literature/documents/in/1746-in026_-en-p.pdf

If you want to do this cheaply, you are going to have to build a converter yourself on a radioshack breadboard. Otherwise, use a PLC. Take an 4-20ma Input card and a 0-200ma Output card and then scale the conversion in the PLC code.

4ma = 0 ma out and 20ma=160ma out.

You will also need to code in safety logic such as wire breaks and/or shorts.

You will also need to initially calibrate the input and output cards and also use the PLC program to calibrate the analog output card.

Allen Bradley or similar may have an off the shelf converter. Search google.

Its not me who want to do the device, but the top post.

I can do it. several transistors and optical couple and a powe supply. less than 3usd.

dont like someone who recommanded the cost up as higher as 400 usd. just like a robber floated on the sea from southern hemisphere.

Why do I need this thing?

The Woodward actuator that positions the governor valve on a steam turbine requires 20-160 mA nominal to move it through its full stroke.

I need to be able to control the valve using a controller that has a 4-20 mA output.

This is why I need a signal converter that takes in 4-20 mA and outputs 0-200 mA. The converter will be used in a chemical plant with all of the requirements for certifications et al.

I could bread board something but that is not the point. I would like to provide the customer with a device that is all pretty in a nice din rail mounted box with the appropriarte pedigree.

Thanks!
Gerald

I guess this reply is meant to be one for our famous CN-power, Famous for not so very intelligent and out-of-topic replies.

Reminds me of the story about the Chinese guy that has been asked "why do you Chinese guys, when asked a question, always answer with a question?"

His reply was: "Why do you want to know? "

Wangito.

wangito, are yoiu a dog? and like bark everyehere when you hungry?

occassionally you occur here, and can youi find some green grass?

I have always refered to them as LVDT controllers and they come from a few suppliers one that I know of is Blac Inc. They also make the Hydraulic actuators as well...

here is another... http://www.macrosensors.com/lvdt_macro_sensors/lvdt_products/index.html

http://www.texmate.com/media/pdf/2008/08/ISL1-2_NZ360_5-18-04.pdf

although some are not Din rail mountable...

Hope this helps...

Look on the web for signal conditioning devices there are a few that have the 4-20 ma input that is directly proportional to the 0-200 ma output. http://www.axiomatic.com/current-converter.pdf ...

http://www.axiomatic.com/signal.html

I don't know about the certifications but these folks seem to have potential.

http://integraelect.com/index.html

Try the following link for custom made transmitters and signal converters.

http://www.jhtechnology.com/index.htm

Try the Company below (B&B).

They specialize in this sort of thing.

But, are you sure you don't want 0 - 20 mA?

B&B Electronics

707 Dayton Rd

Ottawa IL 61350, USA

Phone 815-433-5100

Fax: 815-433-5104

http:\\www.bb-elec.com

Hi

Try to google OTA or Operational Trans-Conductance amplifier. it will give you an exact idea of what you need, and maybe even how to build one if you so choose. You can either buy one (expensive) or design one based on LM-13700 or similar. Because your current requirements are rather low, buying a commercial unit maybe be non-economical. The basic OTA is a constant current source that for a given voltage change at the input it will give a proportional current out-put. You will need the voltage loops at each end. for example, at 4mA at the input you will have 0mA at the output, 20mA will give you 200mA current loop at the output.

I have seen units such as Fluke 5220A selling on Ebay at very low prices. ($400.00-$500.00 range) this could be easily modified for your application and has current range of 0-20A.

Wangito.

400--500?

wangito, are you a greedy racketeer from that narrow country in south america? simply a robber.

less $3 enough to build a 200mA device.

200 times sudden huge profits !

are you being poor to death?

B&B Electronics make good converters and they can do customs also:

http://bb-elec.com/custom.asp

It will be professionally manufactured. You will have to ask them about certification.