In Figure 1, F1 refers to the input fuse.

Proper fuse selection should be a safety agency

approved, slow blow fuse. Selection of the proper fuse rating is necessary to ensure power

converter and system protection (potential failure if the rating is too high) and prevent false

fuse blowing (which could happen if the rating is too low).

Below is the formula to calculate

the proper rating:

= output current;

’s efficiency;

Vin(min) = the minimum input voltage

Futher circuit notations:

rating if the output current is greater than 5A, or a 100

μF rating if the output current is less

than 5A.

The insulation voltage should be derated to less than 80% of rated value.

For dual or triple output converters, the circuit of input side remains the same and the outputs

should be considered independently in component selection (see Figure 3).

The application circuit shown in Figure 1 is typical application circuit, whereby all MORNSUN

products will meet EMI Class B, and Class 3 lightening strike and surge testing (see component

datasheets for more details). To comply with more stringent EMC testing, additional filtering

should be incorporated.

See Figure 2 for a suggested filtering circuit.