Pratica Chef Express Service Manual page 65

High Voltage Transformer
The HV transformer of the microwave circuit is formed by three windings. The primary low/line
tension winding (208/240V), the secondary low tension/voltage winding (3.6V) and the secondary
high tension/voltage winding (2000V), as shown in the scheme below.
The secondary low voltage winding (3.6 volts) acts as a filament transformer and begins to energize
the magnetron by heating the cathode. The magnetron will fully energize when the 2000V are applied
from the secondary high voltage winding causing the emission of electrons that start to produce the
microwave radiation.
The two longer wires of the transformer are the secondary low voltage wires (3.6V) and the wire
grounded to the transformer chassis belongs to the secondary high voltage side (2000V) as seen in
the picture below.
WARNING: Never attempt to measure high voltage directly. Death or serious injury could
result. Always make sure to discharge the capacitor manually before commencing repair.
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