Working principle of the circuit

 After the 220 v voltage outdoor, via PTC1, rectifier H (1), H (2) the rectifier filter into about 280 v dc voltage, the dc voltage after reactor, filter again, all the way to the dc power source to provide power module, the other all the way to the outlet CN401 is end (CN401 end grounding). From CN401 ac motor is set is divided into three road, a path switching transformer T1 transformer of lower left corner (see figure 2) (1) ~ (2) the winding is added to the switch tube N2 collector, a path of R1, R2, C404, R3, L3, R4, R4 step-down into about 8 + v dc voltage, the CPU must first electrical work, another path R402, switch tube provides the bias current base of N2, make its conduction. 

Once the switch tube generator set spare parts N2 conduction, collector current flows through T1 (1), (2) the winding, produce (1) was right in the end, (2) the negative voltage, coupled to the windings (3) ~ (4), (3) end is negative, (4) the positive feedback with a positive voltage, the voltage by the C402, R404 role to N2 b - e, the current in the N2 increase, the positive feedback voltage, fast N2 saturated. In R405, C403, Z401 clamping function, make the N2 work in fixed frequency condition. In the energy storage element wholesalemotor.blogspot.com under the action of T1, out of the T1 secondary induction and stable high frequency ac voltage, D401, C409, D404, C405, D407, C407, D413, C411 rectifier filter into four road + 14 v lamination dc voltage, micro circuit for power module power supply. At the same time from the 6 end of induction voltage by D17, C413, V, C106 voltage into a + 5 V dc voltage to the cPu power supply, such as from the end end voltage produced by D116, C412 rectifier filter into the + 12 V dc voltage, to the micro relay: SWl ICl ~ SW4 and inverter power supply.