Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Load cell interface

Status
Not open for further replies.

Ttushar487

New Member
I am using load cell which has very low output voltage so i decided to use AD524 but i can not understand how to use it
and according to pin diagram pin no 6 which is for reference so what to connect to this pin
 
hi,
If you require unipolar output from the AD524, connect Vref pin to 0V, else connect to +Vref.
Post your circuit diagram so that we can give a better answer.
E
 
Thank you sir,
we get it. But its out put is too high its around 12v for full load and we are interfacing it to pic16f877a so it is possible to connect it direct
 
hi,
You cannot directly connect a 12V input signal into a PIC, it will damage the PIC,
You could use a resistive potential divider.
PLEASE post your circuit.
E
 
Thank you sir,
we are testing this circuit on brad board.so we are not able to send circuit . please tell me can we use other ic instead of AD524 for better responce
thank you
 
please tell me can we use other ic instead of AD524 for better responce thank you

hi 487,
Do you mean a faster response or better amplifier gain?
Tell us about your project, what is it expected to do.?
E
 
Thanks Sir,
we are making conveyor check weight system.
and we want to measure weight of box (60 box per min)
box weight around 520 gm
we are using load cell Which has 20ms setting time
and output voltage 2 mv
 
hi,
The AD524 has a very fast settling time, see image.
It will not present a problem at a weighing rate of 1/second.
The L/C settling time is typical at 20mSec.
Your main problem will be the conveyor mechanics.

Assuming your L/C is specified as 2mV/V of excitation, when using a 10Vdc excitation, that is 20mV for Full Scale output.
If you are using a PIC with a 5V supply and its internal 5V reference, you require a gain of 5V/0.02V = 250.
Use a Vref on the AD524 of 0V [ that is assuming you are using a dual power supply to power the AD524]

E
 

Attachments

  • A01.gif
    A01.gif
    23.6 KB · Views: 328
but we are using two load cell in this project so how to add signal of both load cell

Hi,
Its common practice to wire two L/C's in parallel, it helps if you try to get both L/C's subject to an equal loading.
Look at this attached pdf file.
E
 

Attachments

  • load_cell_cabling_wiring.pdf
    80.7 KB · Views: 646
Last edited:
Thank you sir,
we use ad524 for amplification we set gain of it to 250 by setting RG t
but i cant understand where to connect pin no (4,5,15,14)of ad524
(input null,input null,output null,output null)
 
hi 487,
You should produce a simple circuit drawing of the project, showing what you have connected to the AD524.

It is difficult to help you if we cannot see what you have already done.
Look at figure #47 . page #19 of the datasheet, it shows the NULL on pins 14/15 and the NULL on pins 4/5.
It shows two 10K pots on these pins, that are used to NULL out any 'offset' errors in the AD524 and its circuitry.
OK.?
E
 
Last edited:
Thank you sir,
i send circuit diagram of it from that we get 1.25v with 0 input please send me circuit diagram
 

Attachments

  • IMG_20160116_180939.jpg
    IMG_20160116_180939.jpg
    10.4 KB · Views: 318
The image is too small. Post a larger, clearer one showing all component values.
 
Thank you Sir
We send you new image of circuit
we use AD524 but we cant get desired out put
for 0 input we get 1.25 output instead of 0v
Sir please tell me what to do
 

Attachments

  • tus.jpg
    tus.jpg
    80 KB · Views: 357
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top