DER-75
2.4W Power Supply using LNK520P
September 12, 2005
6.4 Transformer Build Diagram
8
W4
7
Tape
3
W3 Shield
FL1
Floating
Tape
3
W2 Primary
Tape
4
2
1
W1
Cancellation
Figure 5 – Transformer Build Diagram.
6.5 Transformer Construction
Start at Pin 1. Wind 39 turns of item [3a] in approximately 1 layer. Finish
at Pin 2.
Shield 1
Basic Insulation
Use two layers of item [6] for basic insulation.
Start at Pin 4. Wind 114 turns of item [3b] in approximately 3 layers. After
1st layer insert one layer of tape. Complete 2nd layer insert one layer of
tape. Complete 3rd layer. Finish at Pin 3.
Use two layers of item [6] for basic insulation.
Temporary start at Pin 2. Wind 13 turns of bifilar item [3c]. Spread turns
evenly across bobbin. Finish at Pin 3.
Primary
Basic Insulation
Shield 2
(Disconnect from pin 2 and leave floating (FL1) in the stack.)
Basic Insulation
Use one layer of item [7] for basic insulation.
Temporary start at pin 2. Wind 12 turns of item [3d] in 1 layer. Finish on
Pin 8. Move connection from pin 2 to pin 7.
Secondary Winding
Outer Wrap
Wrap windings with 3 layers of tape [item [4a].
Final Assembly
Assemble and secure core halves. Varnish dip (item [6]).
Power Integrations
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