In Midea induction cooker MC-EP192, a triode with Q1 model D667A is a switching triode for the cooling fan.
When the control board provides a high level to the B pole of Q1 through R4, the CE pole of Q1 is on and the cooling fan works. When the work board provides an extremely low level to the B pole of Q1 through R4, the CE pole of Q1 is off and the cooling fan stops.
Diode D15 is a protective diode for Q1, preventing the internal coil from producing reverse potential breakdown Q1 at the moment of closing the cooling fan.
D667A triode is: NPN type low-frequency power amplifier triode, Vceo maximum voltage 100V, Ic maximum current 1A, TO-92L package.