DER-56
UPS Battery Charger - LNK520
April 20, 2005
7.4 Transformer Build Diagram
Figure 5 – Transformer Build Diagram
7.5 Transformer Construction
Pull pins 8-10 on bobbin [2] to provide polarization. Align bobbin on
mandrill with pins 1-5 on right hand side.
Bobbin Preparation
Starting on left hand side of bobbin, wind 34 turns of item [3] uniformly on
a single layer from left to right. Finish winding on pin 4. Wrap start of wire
to pin 5.
Core Cancel/Bias
Basic Insulation
Use two layers of item [7] for basic insulation.
Start at Pin 2. Wind 50 turns of item [4] uniformly on a single layer from
right to left. Apply one layer of tape, wind 50 turns on the secondary, third
and fourth layer (200T total) adding 1 layer of tape [7] between each
layers. Finish winding on pin 1.
Primary
Basic Insulation
Balance Shield
Use two layers of item [7] for basic insulation.
Starting on left hand side of bobbin, wind 21 turns of item [5] uniformly on
a single layer from left to right. Finish winding on pin 3. Wrap start of wire
to right hand side of bobbin and cut close to start of winding leaving it
unconnected (as shown in Figure 5).
Basic Insulation
Use two layers of item [7] for basic insulation.
Start at Pin 7. Wind 23 of item [6] uniformly on a single layer from left to
right. Finish on Pins 6.
Secondary Winding
Outer Wrap
Wrap windings with 3 layers of tape (item [7]).
Final Assembly
Assemble and secure core halves. Varnish impregnate (item [8]).
Power Integrations
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www.powerint.com
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