need amplifier circuit for M831 Electronic YZC 131 5kg weighing weight scale pressure sensor load ce

[balajiraja457]

We already seen this. But we had a doubt about how to select the value of X to get (4-20 ma) output? and also please explain about 7th & 8th pin. Is this necessary to give 2 v to 8th pin? and What about 7th pin? If we use the assumption values of Ra,Rb, Rc as given in your document, can we get (4-20 ma) output? You told to see the output b/w 11th pin and 0v. What did you mean by 0v?

 

[ericgibbs]

hi 457,
I have modelled a 'basic' circuit for the AD694.
Check your circuit against this demo circuit simulation.

I have often used the AD694 for 2V and 10v operation without problems.

E

 

[balajiraja457]

Hi eric,
What is mean by Rtot=500 wiper=.33? What is the value of R8? You mention 0.1R. What is that mean by? & also we have doubt in 0v. what is meant by 0v ?

 

[ericgibbs]

Hi eric,
What is mean by Rtot=500 wiper=.33? What is the value of R8? You mention 0.1R. What is that mean by? & also we have doubt in 0v. what is meant by 0v ?

hi,
R8 0.1R is only for the LTS simulation, so that I can measure/plot the Iout.
In the actual circuit the Iout will go directly to the 4mA to 20mA input of your external device.
The 0.1R will NOT be connected.

Rtot is the 'total' value of a potentiometer ie: 500R variable resistor, the 'Wiper=0.33' means the pot adjuster has be turned ~ 33%

0V is the Common 0Volt connection for the circuit and the AD694, its connected to the 0V/Common of your power supply.
The LTSpice symbol for this connection is a downward point triangle.

Do you follow OK.?
E

 

[balajiraja457]

Thank you eric . We will follow your suggestion. If we have doubt, we will ask you.

 

[balajiraja457]

Hi eric,
We got 4ma output for 0 input. But we can't get an output when we change the input. We can't get an output corresponding to the loadcell output. We get constant ouput(4ma). Give your suggestion to get corresponding output.

 

[ericgibbs]

hi 457,
Could you post a clear photo shot of your circuit layout, so that I can see how you have it interconnected.?
E

 

[balajiraja457]

We got 4ma output for 0 input. But we can't get an output when we change the input. We can't get an output corresponding to the loadcell output. We get constant ouput(4ma). Give your suggestion to get corresponding output. sir this is our circuit diagram for ad694.

 

[ericgibbs]

We got 4ma output for 0 input. But we can't get an output when we change the input. We can't get an output corresponding to the loadcell output. We get constant ouput(4ma). Give your suggestion to get corresponding output. sir this is our circuit diagram for ad694.

hi 457,
Have you tried the circuit for the AD694 using a 2Vdc input test voltage,?? that should give you a 20mA output.

Could you post a clear photo shot of your circuit layout, so that I can see how you have it interconnected.?
I must be able to see how it is actually connected so that I can help you.

E