The number of turns in the primary coil of a microwave oven's transformer can vary depending on the specific model and manufacturer. Typically, the primary coil of a microwave oven transformer has hundreds of turns, often in the range of 200 to 300 turns or more. However, the exact number of turns and the size of the primary coil can differ between different microwave oven models and manufacturers.
The primary coil is responsible for converting the standard household voltage (e.g., 120V in the United States) to a much higher voltage, typically in the range of 2,000 to 2,500 volts, which is needed to power the magnetron—the component responsible for generating the microwaves used for cooking.
As for the size of the primary coil, it is usually wound around the core of the transformer, and the dimensions can vary depending on the specific design of the transformer and the power requirements of the microwave oven.
It's important to note that microwave oven transformers operate at high voltages and can be dangerous even when disconnected from the power source, as they store electrical energy in their high-voltage capacitors. Therefore, any maintenance or repair work on a microwave oven should only be performed by qualified technicians with proper knowledge and equipment. Additionally, always follow safety precautions and guidelines when dealing with electrical devices to avoid any risks of electric shock or injury.