Трансформатор LUNDAHL LL7903. Инструкция на английском языке

Tibeliusgatan 7                        International   Domestic
LUNDAHL                        SE-761 50 NORRTALJE        Phone    +46 - 176 13930   0176-13930
TRANSFORMERS                 SWEDEN                     Fax      +46 - 176 13935   0176-13935
Microphone Input Transformer Transformers
LL7903
The LL7903 is a large, high level, high performance audio transformer, made for extraordinary requirements.
The transformer combines high level capability (+28 dBU @ 50 Hz primary level) with low copper resistance
and is designed for the most demanding applications. The LL7903 consists of two coils, each with two primary
and two secondary windings separated by electrostatic shields. The core is a high permeability mu metal
lamination core.
The transformer is magnetically shielded by a mu metal case.
Turns ratio:                                             1 + 1 + 1 + 1 : 2 + 2 + 2 + 2
Dims (Length x Width x Height above PCB (mm)):           66 x 32 x 21
Pin layout  (viewed from pins side) and winding schematics:
7              14
15   Coil 1
8
1     7                     13    19         1             13 + Core & Can
2     8                     14    20         2              20
15    21                        21
16    22
6              24
5     11                    17    23                        23
6     12                    18    24         5             16     Coil 2
12
11              18
17
Note! Isolation between shields is not guaranteed!
Spacing between pins:                     5.08 mm  (0.2")
Spacing between rows of pins:             5.08 / 45.72 mm  (0.2 / 1.8")
Weight:                                   155 g
Rec. PCB hole diameter:                   1.5 mm
Static resistance of each primary (average):                           28W
Static resistance of each secondary (average):                        125W
Distortion (primaries connected in series, source impedance 600W ):   + 10 dBU primary level, 50 Hz:
0.1 %
+ 28 dBU primary level, 50 Hz:
1 %
Self resonance point :                                                80 kHz
Optimum termination for best square-wave response             30kW in series with 400pF
(source imp.  600W ) :
Frequency response                                            10 Hz - 70 kHz +/- 0.5 dB
(source and load as above)
Isolation between primary and secondary windings/ between windings and shield:  4 kV / 2 kV
R030216

LUNDAHL
TRANSFORMERS
Connection alternatives, LL7903
Left side connections                                    NOTE! Pin side view
+
+
1    7                        1     7                         1     7
2    8                        2     8                         2     8
5    11                       5     11                        5     11
+                                        6     12
6    12                       6     12
L4                              L2                             L1
Right side connections                                   NOTE! Pin side view
13     19    +                 13     19        +              13     19      +
14     20                      14     20                       14     20
15     21                      15     21                       15     21
16     22                      16     22                       16     22
17     23                      17     23                       17     23
18     24                      18     24                       18     24
R4.    Center tap at 17       R2.    Center tap at 20+23               R1
Suggested applications using LL7903
Application                          Max primary level,   Connections
< 1% THD@50 Hz
Microphone / line input 1:2          +28 dBU             L4 - R4
Microphone / line input 1:4          +22 dBU             L2 - R4
Microphone / line input 1:8          +16 dBU             L1 - R4