Note: In original design, obligate inductance L1, L2, CBB capacitance C1, C2 serves as conduct test component, obligate magnetism bead FB1, pottery and porcelain sticks a capacitance C9, stick a resistor R14, R15 to test cell as radiation;

 

Conduct a test:

 

1, short receive L2, l1=4.7mH, c1=0.1uf, c2=0.1uf, 120V voltage is inputted, l line conducts image:

 

 

277V voltage is inputted, l line conducts image:

 

 

Result: Input 277V, near the surplus after the frequency of 150K reads a feature is little at 3db

 

Rectify and reform method: Increase C2 0.22uf, check image to be as follows again:

 

 

Result: The hand is moved read a feature, surplus 7.19db, after line of N of test and verify, pass without pressure.

 

Radiation checks:

 

1, imposing the magnetism bead FB1, condition that does not impose annulus road capacitance, transformer not to wrap cupreous skin, radiation data exceeds bid badly;

 

2, rectify and reform plan: Will rectify and reform the position to strengthen as follows, namely: Increase magnetism bead FB1(100M 60ohm) , c9=1nf of annulus road capacitance.

 

Result: The level checks, surplus approachs limit line; Perpendicular test, 31MHZ, 41MHZ, 53MHZ is in radiation data to exceed mark 5-10db;

 

3, rectify and reform plan: Be based on the 2nd pace, transformer use copper skin undertakes exterior coil laps, increase C9 to 2.2nf; at the same time

 

Result: The circumstance does not have improvement;

 

4, rectify and reform plan: Be based on the 3rd pace, the D that is in charge of Q2 in MOS, S pole receives 60pf capacitance;

 

Result: The circumstance does not have improvement;

 

Image is as follows:

 

 

5, rectify and reform plan: The key pays close attention to high frequency switchpoint (following red circles are in) , adjust Layout wiring design:
 

 

In original wiring plan, part of advertent and high frequency switch (the black line that makes “X” ) , discovery is high frequency walk along a line to grow too, annulus road area is too large:

 

 

After new position, Layout:

 

 

Result:

 

The design parameter that does not add FB1(100MHZ 60ohm) of C9=2.2nf of capacitance of road of cupreous skin, annulus, magnetism bead in transformer: 120V level, perpendicular test pattern resembles

 

 

277V 60HZ level, perpendicular test pattern resembles:

 

 

Test and verify conducts data:

 

120V 60HZ Line of L, N:

 

 

277V Line of 60HZ L, N:

 

 

Result: The test is passed!