DER-120
22 W Triple Output Flyback – DPA424R
October 26, 2005
7.3 Transformer Build Diagram
Figure 5 – Transformer Cross-Section
7.4 Transformer Construction
Primary
Start at Pin 2. Wind 17 trifilar turns of item [3] uniformly on a single layer.
Finish on pin 1.
Basic Insulation Use one layer of item [5] for basic insulation.
Bias Winding
Start at Pin 5. Wind 6 turns of 9 strands of item [3] uniformly on a single
layer. Finish on Pin 4.
Insulation
Use 3 layers of item [5] for basic insulation.
+3.3 V Winding Prepare cuffed foil assembly. Start at Pin 10. Wind 2 turns of item [4].
Finish on pin 7 and 9.
Basic Insulation Use one layer of item [5] for basic insulation.
+9 V & +12 V
Windings
Wind +9 V and +12 V windings simultaneously and uniformly on a single
layer. Start +9 V winding on pin 8 with 7 strands on item [3] and start +12 V
winding on pin 6 with a quadfilar item [3] make 3 turns and finish +9V
windings to pin 10. Continue +12 v windings an additional 5 turns and finish
on pin 8.
Outer Wrap
Wrap windings with 3 layers of tape [item [5].
Final Assembly Assemble and secure core halves. Dip varnish cores (item [6]). Do not
impregnate
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