Hello,
This in amp is showing some unexpected behavior.
The voltage output is normally near zero. After 10 minutes the output still fluctuates with the input, but the output voltage drops to -3 volts offset or so.
Have you ever seen this? What's wrong? View attachment 60255
Thanks,
John
Is the Load cell temperature compensated? Sounds to me that the input is dropping off (as Carl implies) read the mV on pin 2 & 3 on startup & 10 minutes running.
If it's a 350 ohm bridge the zero drift due to temperature should be minimal... If it's a 1k bridge then it could be that. -3 volts with a 100 ohm gain resistor is about 6mV drift (a bit high)
BUT, when I disconnect the load cell from the AD620, the load cell outputs (top and bottom of bridge in fig.) are both 5.007v, which is correct. I know the load cell is working.
John
BUT, when I disconnect the load cell from the AD620, the load cell outputs (top and bottom of bridge in fig.) are both 5.007v, which is correct. I know the load cell is working.
John