There following is the instrumental amplifier build from 3 opamps
But there is somethings strange with the power supply.
+Vcc does nothing to the output because it provide power to operate the system
so the output does not change when i change +Vcc
But, when I change -Vcc away from zero, its value add to the output and make the percentage change in output small. why -Vcc would do such an effect? I thought +Vcc and -Vcc only provide the power for devices and the range for the output.
But there is somethings strange with the power supply.
+Vcc does nothing to the output because it provide power to operate the system
so the output does not change when i change +Vcc
But, when I change -Vcc away from zero, its value add to the output and make the percentage change in output small. why -Vcc would do such an effect? I thought +Vcc and -Vcc only provide the power for devices and the range for the output.