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ISSUE
DRAWING NO.
DRAWING TITLE
DATE
Filename:
ECO No.
DESCRIPTION OF CHANGE
L925TX_1.1.Sch
DV78 450uH FLYBACK TX
Contact Engineer:
L925TX
8-Oct-2003
INITIALS
Printed:
1
1
Sheet
of
Notes:
Contact Tel:
(01223) 203200
Kevin Lamb
A & R Cambridge Ltd.
Pembroke Avenue
Cambridge CB5 9PB
Waterbeach
VIEW FROM TOP OF PART
ELECTRICAL REPRESENTATION
WINDING DETAILS
WINDING
WIRE DETAILS
START
END
NOTE PIN NUMBERING CONVENTION
MATERIALS
CORE
PQ32/30 in PC44 MATERIAL (OR EQUIVALENT)
BOBBIN
ASSEMBLY DETAILS
PART TO BE MARKED WITH PART NUMBER / ISSUE NUMBER
1
2
3
4
5
7
10
11
12
PRIMARY1
PRIMARY2
SECONDARY1
SECONDARY2
SECONDARY3
SECONDARY4
SECONDARY5
PRIMARY2
SECONDARY1
SECONDARY2
SECONDARY4
SECONDARY5
9
10
7
8
11
12
SECONDARY3
PIN #
PIN #
TURNS
41
41
14
10
22
WINDING ARRANGEMENT ON BOBBIN
PRIMARY1
PRIMARY2
SECONDARY5
SECONDARY1
SECONDARY2
SCREEN2
SCREEN1
+
1 FULL LAYER WIND AS BIFILAR PAIR
WIND SECONDARY 4 FIRST THEN SECONDARY 3 IN THE GAPS
SCREEN TO BE HIGHEST POSSIBLE RESISTANCE FOIL FOR LOWEST LOSSES. (I.E. FOIL AS THIN AS POSSIBLE)
CORE TO BE GAPPED IN CENTRE LEG TO GIVE REQUIRED Lpri (GAP APPROX 0.4mm)
(Lpri = 450uH +/- 10% PRIMARY INDUCTANCE MEASURED FROM PIN 1 TO 3 )
A.0
Prototype Release
KAL
20-11-02
6
8
9
ID
OD
ENAMELLED COPPER WIRE
No PER
CABLE
1
1
1
2
1
0.25mm
4
5
5
6
SEC1 AND 2 WOUND AS BIFILAR PAIR ACROSS FULL WIDTH
1 FULL LAYER
INTERNAL SCREENS TO BE FULL WIDTH. CONNECTION TO SCREEN VIA SOLDER JOINT TO COPPER (SEE DIAGRAM)
SOLDER JOINT TO BE ARRANGED TO PRODUCE A LUMP IN THE CORE WINDOW
INSULATOR
WIRE
SOLDER JOINT TO BE COVERED IN TAPE
SOLDER JOINT TO MADE MADE TO CLEAN COPPER AND JOINT TO BE TAPED.
BUMP FROM SCREEN JOINT TO BE
TO MINIMISE LOSS OF WINDING HEIGHT
FULL WINDING WIDTH
FOIL (2mil OR THINNER)
JOINT MUST BE MADE TO CLEAN COPPER
(I.E. NOT THROUGH MYLAR INSULATOR)
WITH PART INSTALLED IN PCB
1
2
ARRANGEMENT OF INTERNAL FOIL SCREENS
ADJACENT TO CORE WINDOW
NOTES
WIND SEC1 AND SEC2 AS A BIFILAR PAIR ACROSS
SCREEN 1
1
INSULATED 2mil COPPER FOIL
SCREEN 2
3 WINDINGS WILL BE A TIGHT FIT ON BOBBIN. NOTES AND WINDING ARRANGEMENT SPECIFIED TO BE ADOPTED.
1 FULL LAYER
ENAMELLED COPPER WIRE
ENAMELLED COPPER WIRE
ENAMELLED COPPER WIRE (BIFILAR)
ENAMELLED COPPER WIRE
1.2 INCH
1.1 INCH
MAXIMUM OVERLAP ON ENDS OF
SCREENS TO BE LESS THAN 1mm
TO MINIMISE CAPACITIVE COUPLING
WHICH WOULD PRODUCE SHORTED
TURN FOR HIGH FREQUENCY CURRENTS
1
2
SCREEN TO BE MADE FROM MAXIMUM 0.05mm (2MIL) FOIL
0.3mm
2 LAYERS MYLAR TAPE
SECONDARY4
3
2
16
1
0.8mm
0.86mm
ENAMELLED COPPER WIRE
1
INSULATED 2mil COPPER FOIL
2
1
PRIMARY1
16
1
0.8mm
0.86mm
ENAMELLED COPPER WIRE
0.72mm
0.66mm
0.72mm
0.66mm
0.25mm 0.3mm
0.25mm 0.3mm
WHOLE BOBBIN WIDTH
WIND AS A BIFILAR PAIR ACROSS WHOLE BOBBIN WIDTH
SPACE WINDING ACROSS WHOLE BOBBIN WIDTH
WIND ACROSS WHOLE BOBBIN WIDTH BETWEEN GAPS IN SEC4
SPACE WINDING ACROSS WHOLE BOBBIN WIDTH
SPACE WINDING ACROSS WHOLE BOBBIN WIDTH
SCREEN TO HAVE NO OVERLAP AT ENDS
1
2
3
4
5
7
10
11
12
6
8
9
SECONDARY3
+
SOLDER JOINT TO BE MADE HALF WAY ALONG LENGTH OF THE FOIL
PART NUMBER TDK PC44PQ32/30Z-12 (OR EQUIVALENT)
PART NUMBER TDK BPQ32/30-1112CP (OR EQUIVALENT)
CLAMP
PART NUMBER TDK FPQ32/30-A (OR EQUIVALENT)
4 TRANSFORMER TO BE FITTED WITH AN OUTER COPPER SCREEN WRAPPED AROUND THE OUTSIDE OF THE
SOLDER JOINTS TO BE MADE HALF WAY
3
ALONG LENGTH OF FOIL FOR REDUCED LOSSES
5 PIN 1 ON BOBBIN TO BE MARKED WITH WHITE PAINT (OR OTHERWISE)
THIS MARKING TO BE USED TO ORIENTATE TX DURING WINDING PHASE TEST
TRANSFORMER IS TO BE USED ON SECONDARY SIDE OF MAINS
ISOLATION BARRIER (I.E. THIS TRANSFORMER IS NOT REQUIRED
TO PROVIDE MAINS ISOLATION BARRIER)
MAXIMUM VOLTAGE BETWEEN WINDINGS <60V
PIN 1 TO BE MARKED
NOTE.
SCREEN TO HAVE NO OVERLAP AT ENDS
7
2
3
16T
16T
22T
14T
10T
8
1
11
10
9
12
4
41T
41T
5
6
S
C
R
TX2
Ferrite Switch Mode
L925TX
02_E336
B.0
Changed Pri1,2 and Sec1,2 turns, Lpri & gap, Added outer screen
KAL
21-03-03
02_E086
6 100% PHASE TEST AND ISOLATION TEST TO BE CARRIED OUT ON ALL WINDINGS.
OF THE TRANSFORMER CORE AND CONTACTING THE METAL CORE CLAMP THUS FORMING A SHORTED TURN
SCREEN TO BE 10THOU COPPER STRIP 6 to 8mm WIDE AND FITTED OVER THE JOIN OF THE CORE HALVES.
TO LEAKAGE FLUX. SEE DIAGRAM
SCREEN TO BE COVERED IN A LAYER OF TAPE.
6 to 8mm 10THOU COPPER
OUTER SCREEN
ELECTRICALLY CONNECTED TO CORE CLAMP
CONDUCTIVE ADHESIVE FOIL MAY BE USED
FOIL TO BE COVERED IN A LAYER OF MYLAR TAPE
SHORTED TURN FOIL SCREEN TO BE
1.0
Production Release
KAL
02-07-03
02_E195
1.1
'VIEW FROM SIDE OF PART SHOWING PIN LENGTH DIMS' added.
SLS
06-10-03
03_E290
SEE VIEW GIVING PIN
LENGTH DIMENSIONS
VIEW FROM SIDE OF PART
SHOWING OUTER FOIL SCREEN
VIEW FROM SIDE OF PART
SHOWING PIN LENGTH DIMENSIONS
PCB
MATING FACE OF TX
7 REF.
2.5 MAX