Pins number are shown on resistors next to relay
Pin1: Offset null
Pin2: Inverting input
Pin3: Non-Inverting input
Pin4: V-
Pin5: Offset null
Pin6: Output
Pin7: V+
Pin8: NC
Because it might crash at the beginning, I use these relays to prevent it crashing.
I also built an ideal circuit at bottom equivalent to upper one.
