EPR-00011 - 70 W adapter 22-Jan-01

Page 13 of 46

Power Integrations Inc

Tel: +1 408 523 9200 Fax: +1 408 523 9300

ww: http://www.powerint.com

TRANSFORMER DIAGRAM:

Pin Side

Secondary [4]

1/2 Primary [3]

Bias [5]

Tape [6]

Shield [5]

Tape [3]

1/2 Primary [3]

SHIELD and BIAS Winding PREPARATION:

(Top View before folding tape)

(Cross Section)

Copper

Tape

12.0

65 for Shield and 120 for Bias Winding

8.0

20.0

Copper Foil

Tape

2.0

4.0

#26 copper wire

(only one required for shield)

(Top View after folding tape)

Figure 1-A

Figure 1-B

Figure 1-C

EPR-00011 - 70 W Adapter 22-Jan-01

Page 14 of 46

Power Integrations Inc

Tel: +1 408 414 9200 Fax: +1 408 414 9201

ww: http://www.powerint.com

TRANSFORMER CONSTRUCTION:

1/2 Primary Winding

Start at pin 2. Wind 9 turns of 2 parallel strands of item [3]

from left to right. Wind a single layer and finish at pin 1.

Shield Band (*see diagram)

Prepare cuffed foil [5]. Start at unterminated end of foil and

wind one (1) complete turn of foil around bobbin. Terminate

at pin 1 and cover with tape [8].

Secondary Winding

Attach Tri-filar item [4] to pin 12. Attach Tri-filar item [4] to

pin 11. Interleaving windings, wind across the bobbin.

From pin 12, wind 3 turns and finish at pin 9. From pin

11,wind 3 turns and finish at pin 8.

Foil Band (*see diagram)

Prepare cuffed foil [5]. Start at pin 6 and wind 2 complete

turns of foil around bobbin and terminate at pin 5.

Basic Insulation 1 layer of tape [8] for insulation.

1/2 Primary Winding

Start at pin 3. Wind 9 turns of 2 parallel strands of item [3]

from left to right. Wind a single layer and finish at pin 2.

Basic Insulation 1 layer of tape [8] for insulation.

Core Affix center gapped core to bobbin.

Final Assembly and Core Contact

Wrap core with copper foil tape [6] Attach wire to pin 1 and

to copper tape.

Apply Tape to outside of Core Wrap one layer of tape [10] around core. (see figure above)

Impregnation Varnish Impregnate using [9]

6.1 Transformer Sources

For information on the vendors used to source the transformer, please visit our website at

the address below and select Engineering Prototype Boards

http://www.powerint.com/componentsuppliers.htm

Due to proximity of

secondary components

(R4, R13), wrap one

layer of tape [10] around

core.

EPR-00011 - 70 W adapter 22-Jan-01

Page 15 of 46

Power Integrations Inc

Tel: +1 408 523 9200 Fax: +1 408 523 9300

ww: http://www.powerint.com

7 Transformer Spreadsheet

ACDC_TOPGX_Rev0.2_090100





 Power Integrations Inc. 2000

INPUT INFO OUTPUT UNIT

TOP_GX_090100.xls: TOPSwitch-GX

Continuous/Discontinuous, Flyback Transformer

Design Spreadsheet

ENTER APPLICATION

VARIABLES

Customer

VACMIN 85 Volts Minimum AC Input Voltage

VACMAX 265 Volts Maximum AC Input Voltage

fL 50 Hertz AC Mains Frequency

VO 19.2 Volts Output Voltage

PO 70 Watts Output Power

n 0.85 Efficiency Estimate

Z0.5LossAllocation Factor

VB 12 Volts Bias Voltage

tC 3 mSeconds Bridge Rectifier Conduction Time Estimate

CIN 150 uFarads Input Filter Capacitor

ENTER TOPSWITCH-FX

VARIABLES

TOP-FX top249

Universal 115 Doubled/230V

Chosen Device TOP249 Pout 135W 300W

KI 0.55

External Ilimit reduction factor (KI=1.0 for default ILIMIT,

KI <1.0 for

lower ILIMIT)

ILIMITMIN

2.67

Amps Use 1% resistor in setting external ILIMIT

ILIMITMAX

3.18

Amps Use 1% resistor in setting external ILIMIT

Frequency - (F)=130kHz,

(H)=65kHz

f Full (F) frequency option - 130kHz

fS 132000

132000

Hertz

TOPSwitch-FX Switching Frequency: Choose between

132 kHz and 66 kHz

fSmin

124000

Hertz TOPSwitch-FX Minimum Switching Frequency

fSmax

140000

Hertz TOPSwitch-FX Maximum Switching Frequency

VOR 120 Volts Reflected Output Voltage

VDS 8 Volts TOPSwitch on-state Drain to Source Voltage

VD 0.7 Volts Output Winding Diode Forward Voltage Drop

VDB 0.7 Volts Bias Winding Diode Forward Voltage Drop

KP 0.60

Ripple to Peak Current Ratio (0.4 < KRP < 1.0 : 1.0<

KDP<6.0)

ENTER TRANSFORMER

CORE/CONSTRUCTION VARIABLES

Core Type

PQ26/2

Core #N/A P/N:

#N/A

Bobbin #N/A P/N:

#N/A

1.19 1.19 cm^2 Core Effective Cross Sectional Area

0.463 0.463 cm Core Effective Path Length

6170 6170 nH/T^2 Ungapped Core Effective Inductance

9.2 9.2 mm Bobbin Physical Winding Width

M0mm

Safety Margin Width(Half the Primary to Secondary

Creepage

Distance)

L1.4Number of Primary Layers

NS 3 Number of Secondary Turns

Part #	EP11
Description	SWITCH PUSHBUTTON BLACK
Category	SWITCH
Availability	In Stock
Qty	402

Qty	Price
1 - 41	$3.58179
42 - 105	$2.84915
106 - 204	$2.68635
205 - 310	$2.49640
311 +	$2.22505

EP11

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Technical Document