Microwave Transformer

These vary in power output and design, but can be readily salvaged and studied. Frequently used for DIY projects involving welders and high voltage, they provide a potentially lethal current. The core of the transformer is commonly composed of many thin slices of transformer steel which are shaped and then painted with insulating adhesive and stacked together to the desired height. Two coils of enameled copper wire can be salvaged from each core, and the ratio in the number of turns between both coils determines the voltage and current output of the transformer. Its possible to re-wind the transformers secondary coil to produce different outputs of voltage. The secondary coil is the coil with many turns of fine wire, while the primary coil is usually a low gauge thicker wire with fewer turns.

Photo of salvaged Microwave Transformer
Photo of Microwave Core disassembled
Free-cad Model of Microwave Transformer Core dimensions.

While electrical specifications of cores vary by model and manufacturer, the main cause for variation is the different voltage and frequency of the country in which the microwave was built. Inputs of 100V/110V/120V/220V/230V/240V as well as outputs from 500V to 1200VA variations of the transformer exist in countries that use either 50hz or 60hz power. A transformer core rated for 60hz is smaller than one rated for 50hz for the same reasons a smaller bell produces a higher pitch.