hi..

how to gain up the 4-20mA signal loadcell because the initial ready less than 4mA..

 

Welcome to AAC!
Here's one suggestion for boosting loop current:-

The ratio R1/R2 sets the current gain.

 

ok.. is it possible if i change the R1 & R2 with variable resistor? any suggestion what kind of ohm need to use if put variable resistor??


thanks buddy..

 

LM358NS -
Low Power Dual Op-Amp

there are have 2 output.. which output need to use?
one more thing, what mean with u1a?

 

Here you go. R1 has been replaced with a pot but R2 should be left as is. You only need one opamp in the LM358NS dual package. I've labelled it U1a in the schematic and shown the pin connections. The other one, labelled U1b, isn't used; nevertheless its inputs (pins 5 and 6) can't be left 'floating', so I've shown how those are connected too. I have assumed you have a well-regulated 12V (or 24V, or whatever) supply for the circuit. Q1 can be almost any smallish NPN transistor, e.g. 2N3904.

 

hi alec'
Attachment error msg.
E

 

Hi Eric. Looks ok from here. Perhaps you got the error message while I was mid-way through posting an edited schematic?

 

hi alec,
It's visible now.
E

 

hi..

how to gain up the 4-20mA signal loadcell because the initial ready less than 4mA..

Look @ http://www.ti.com/lit/ds/symlink/xtr115.pdf

Picbuster