
Here are the internals of a cheap Microwave/Convection Oven combo. Electronics bay is pretty much the same as a standard microwave, with the magnetron, transformer & diode/capacitor voltage doubler, with the addition of an extra fan & a pair of nichrome elements to provide the convection oven function.

Convection blower which keeps the cooking vapours & smoke away from the elements, & circulates the hot air around the cooking chamber. This is a 12v DC centrifugal type blower.

The elements are inside this steel shield, air duct extends from the centre.

This oven has a pair of thermal switches on the magnetron.

The usual capacitor/diode voltage doubler in the magnetron power supply. The transformer is visible to the left.

Electronic controller PCB. This has a pair of relays that switch the elements & the magnetron transformer.