I am looking for an inexpensive way to convert a 0 to 5 Vdc signal from a pressure transducer to a 4 - 20mA signal. Does anyone have a better solution or some simple calculations I should make to ensure that I will get the best results?

Thanks In Advance:

Wahba Atia

 

This little device will fix you up. See the manual and picture at: http://www.almegcontrols.com/4-20_converter.htm

Thanks Bob Hogg

 

I'm not sure what your inexpensive is. This unit will do the job:

http://www.actionio.com/support/datasheets/actionpak/ap4380-2000.pdf

The "list price" I got NOW was about $345. The unit is DIP-switch configurable for your I/O requirements. Looks like the standard model needs 120 or 240VAC power. The 9 to 30VDC power supply is "Optional".

JC

 

You could just use a 250 ohm resistor... that would give you 1-5 VDC. Then just scale your input to start at 1 VDC not 0.

But this will probably be an unpopular solution in this forum.

jb

 

Send me an email to [email protected] and I'll send the circuit drawing. It's a popular one.

Regards

cww

 

I have one right here, an inexpensive circuit that converts a 4 - 20mA signal into 0-5V. I have recently made a little pcb for it, just 1 IC and a handfull of other components. I estimate the total cost in the area of $75.

Regards,
Flyer

 

Another option is the AutomationDirect model FC-33 signal conditioner. I haven't used any yet, so cannot speak to it's performance or reliability, but it's only $119, and about as cheap as I've seen for a commercial product. It requires a 24 volt DC power supply for operation, features selectable 0-5 VDC, 0-10 VDC, 0-20 ma, and 4-20 ma inputs, and outputs, and is DIN rail mounted.

One thing, Automationdirect only does direct sales in the US and Canada, so, depending on where you are located, you'd need to go through one of their international vendors.

For instance, the one for the Middle East is:

TOPCO Control & Automation LTD.
99 Medinat Hayehudim St.
PO Box 12504, Herzlia
46733
Israel

Phone: 972 9 9588008
Fax:972 9 9587953
E-mail: [email protected]

Regards,
Bob