Homemade refrigerator monitor

This monitor uses a discarded micro-ampere meter as the refrigerator ammeter. It is divided into two gears when measuring current to expand the range of small current. The large current gear measurement range is 0-10A, and the small current gear measurement range is 0-2A. The large current gear is used when measuring the refrigerator starting current, and the small current gear is used when measuring the working current (in actual use, the starting time is within two seconds, and it is switched to the small current gear after starting). The circuit diagram is shown in the figure below.