Load Cell Amplifier Needed

[SABorn]

That looks to be a strange way you have the load cell configured with your wiring, try V+ and V- supply direct to the cell and V+ and V- output from the cell direct to the chip inputs.

The only time you would normally have a pot in there is to balance more than 1 cell to read the same as the others, even then i have never seen it done as you have.

Pete.

 

[Reloadron]

I don't understand the gain configuration on the AD624? While I have never used the 624 I have used the 524 and don't understant why your gain is configured as it is.

Ron

 

[asimzia]

Thanx Ian Rogers

but this AD624 is working perfectly i have no issues with it
the issue is of comparator

without comparator all things work fine
but when i attach comparator, the change in weight on load cell does not affect the output of amplifier

 

[asimzia]

thanx SAborn

it is just actually mentioned in data sheet of AD624
the load cell is working in both ways whether directly connected to supply or with the above given circuit diagram

but issue is of comparator as i have mentioned
amplifier is working perfectly

 

[asimzia]

THanx RON

the gain from AD624 is pin configurable and is configured to be 1000

but issue is of comparator
amplifier is working perfectly as i have mentioned

 

[Reloadron]

Your drawing shows two 741 operational amplifiers? The pins make no sense? The first is shown as a non inverting amplifier with a max gain of about 100 with pin 11 going to power (it's an 8 pin chip) and pin 4 to ground. The second has power and ground reversed with pin 11 going to 0 volts? The 741 is a poor choice and will not work well single ended (if at all) with a 5 volt supply as a comparator it is an old op amp and not a rail to rail op amp. If you want to use the first op amp for gain and the second as a comparator I would use a single TL082 and drop the 741s. Actually I would use a TL081 for the amp and a LM311 for the comparator as the LM311 will work off a single supply.

Ron