Winding of high frequency transformer in switching power supply

1: the use of special transformer design software, will require parameters, such as input voltage, output voltage, bias voltage, transformer size estimation power, power factor, rated load, the primary coil and the secondary coil number of turns of input parameters, PI software according to user input parameters are given a reasonable transformer the parameters, then the designer can according to the given parameters of transformer winding, the software will have the following parameters: the primary coil, the feedback coil and the secondary coil number, number of turns and line through the tape winding between the size, direction, size of the gap, the coil and coil number, skeleton model, core the type, impregnation requirements.

2: these parameters can be winding of transformer, give the skeleton pin a number before the winding of transformer for example, we now need a winding of the input voltage is +24V, output is 1 +9V, the output is 2 +15V transformer, power output for 1.5W 2 then, the transformer winding method are as follows:

Primary coil winding method: starting from pin 2, the use of wire diameter of 0.19 mm of the wire around the skeleton 53 circle, it is estimated that there are two layers, the wire should be as smooth as possible. At the end of pin 1, after using the insulating tape wrapped around the two layer.

The bias coil winding method: from pin 5 to use the diameter of 0.13 mm enamelled wire wound frame 27 to pin 4 ring around the end, after using the insulating tape wrapped in two layers, and a layer of insulating tape wrapped in pin other than all coil exposed places.

9V end of the coil winding method with insulating tape wrapped in 7 feet and 6 feet, enameled wire using wire diameter 0.35 mm, from 7 feet to 6 feet to 20 times around the end, with insulation tape wrapped in two layers. Then the insulating tape wrapped around 7 feet 6 feet outside the winding.

15V end of the coil winding method with insulating tape wrapped in a 10 foot 9 feet, enameled wire with the diameter of 0.19 mm, from 10 feet to 9 feet to 34 times around the end, with insulation tape wrapped in two layers, and then loaded on two cores, 0.3MM thick paper in the middle two cores (i.e. the air gap, about 4 layers of white paper thickness), flattened tape the core and skeleton wrapped together. (that means 4KV insulating rubber insulating tape)

EPC13 skeleton pin diagram is as follows:

3: test transformer output and load capacity

Test method: will be installed around the transformer has been successfully tested on the test board, the detection circuit output and load capacity, if the output and load capacity of the normal test transformer capacity.

4: test transformer capacity.

The transformer voltage test is divided into three groups, that is, the primary end (1, 2 feet), 9V (6, 7 feet), 15V (9, 10 feet). In any of these two groups end with 3KV AC voltage for 20 seconds (clamps which each end of any foot, feet can also be full clip), pressure test instrument alarm the transformer failure, no alarm is qualified.