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Introduction
TOMITA Coils/Transformers○Custom Coils/Transformers design & Production
Design and produce C/T with our ferrite cores following
the customer’s requirements.

○ Quality and efficient C/T with ferrite
technology○Wide variety of ferrite materials and high end winding
technology
Designing to delivery, Tomita can meet the customer’s needs andoffers the short lead time.

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Tomita C/T
1. Design
Expertise in designing the transformers for power supply, choke, filter, converter, transmission,sensor, planer, etc.
For power supply, mainly designing 1W-9W level (core size EE-5 to EE-30) transfomers. Focus on all
types of circuit and smaller size.
Higher efficienty with Tomita’s low power loss ferrite cores.
Offering various type of ferrite materials to meet the customer’s requirements.

2. Using Tomita Ferrite Cores
Various type of shape and dimension
Short lead time (1wk for mold production)
Selection of ferrite materials

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3. Winding Technology- Regular winding, multi layer,space, edegewise, etc

4. Safety Standard- UL certified and other standards

Faster than competitors

5. Lead Time
- Samples: 3 days (if stock available)
2-3wks (if new mold necessary)Within 3 days (spec change)- Production: Ramp up in 1 and half months (negotiable)

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6. Quality Assurance- Verified pre-production in headquarter factory, mass-production in overseas
factory- Ramp up managed by production managers.
Quality control by well-trained local staff.

7. Cost- High-mix, low-volume can be managed by overseas production

8. Service and Delivery- Delivery location and term can be negotiable- JPY, USD, RMB

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TOMITA C/T Design/Production Process

Production

Customer approval

Pre-production samples

Customer approval

SamplesCustomer approval

Design proposal

Customer specification

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Product Design6

Forward converter type
Switching power supply C/TCommon mode choke coil
EMI/RFI filter

AC inNoise filter

Active filter choke coil

Main transformer

Auxiliary power transformer

Output rectification
Smoothing circuit

PFC
Active filter

Auxiliary power circuit

Smoothing choke coilPower switchcircuit

Switching element drive transformer

Control circuit

Current transformer

DC outPage

Product DesignTransformer

7Coil- Flyback transformer- Forward transformer- Others- Pulse transformer- Current transformer- Common mode choke coil - PFC choke coil
- Normal mode choke coil
- Others

Circuit Type

Non-isolatedIsolated1) Step-down chopper

Self-excitedoscillation flyback
type
Output: until 40W
level2) Step-up chopper

Various local
regulator-Various local regulator-Mobile phone batery charger-Small AC adaptor

Separately
oscillation flyback
type
Output: until 70W
level

Separately
oscillation forwardtype
Output: until 90W
level

Separately
oscillation, pushpull, half-bridge,
full-bridge
Output: until 90W
level-AC adoptor-General printer-Standard power
supply-PC, EWS-Server-Large size printer-PC, EWS-Server-Large size printerPage8Non-isolated

Isolated

Step-up chopper

Self-excited flyback

ForwardPush-pull

Step-down chopper

Separately-excited
flyback

Full-bridge

Half-bridge

Regular switching powertransformer

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9Features● Miniaturized by using low power loss, highmagnetic flux density, high permeability ferrite core● High efficienty● RoHSApp.

● Applied to factory appliance to home allianceprojects. Widely used for switching transformer.

Shape, Dimension◎ E series (EE-5～33) (EPC-10～25)●EPC-10●EE-3311.6

31.1

114.9534.2

13.2◎EI series (EI-12.5～28)●EI-12.5●EI-28

9.1
25.1
12.6

828

22

Low back type switching powertransformer

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10Features● Miniaturized by using low power loss, highmagnetic flux density, high permeability ferrite core● High efficienty● Automatic implementation● Small/low-back type
● RoHSApp.

● Switching power supply for low-back products
such as audio, LCD and PDP

Shape, Dimension◎ E series (EFD-12～25) (EER-7.5～25)●EFD-15●EFD-25

12.6

25.1
12.6

825.1

13.2

◎ EPC series (EPC-10～25)●EPC-10
11.6●EPC-2525.1

114.9525.1

16

Various communicationtransformers

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11Features● High speed communication

App. Shape, Dimension● Communication tools
High speed modem● Wide frequency● RoHS◎ EP series (EP-7～20)●EP-7●EP-20

7.5
21.6
9.2

9.4
24.0

19.2

◎ RM series (RM-4J～10J)●RM-4J●RM-10J

9.8

24.7
9.8

10.5
24.7

18.7

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Common mode choke coils

12Features● Broadband

App. Shape, Dimension● For various types of power supply, noise
remover for power and signal● High inductance● RoHS◎ TR series (TR-6X3X2～31X19X13A)●TR-6X3X2●TR-16X6X455.5

914●TR-12X6X45.5●TR-9X5X5810.8

10.8
18.5

10

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Line filter

13Features● High inductance● Sperior high frequency attenuation● Small size, light weight● Broadband● RoHS

App. Shape, Dimension● Noise prevention for conduction noise from low tohigh freq, around the power area of electronics◎ UU series (UU-9.8～18)●UU-9.8●UU-18X2115.2

29.5

15.68
23.1

22

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Choke coils

14Features● High current model using High-μ，High-Bm ferritecores● Wide area inductance● Magnetic shield type
● RoHS

App. Shape, Dimension● Choke coils for power supply◎ DR series (DRW-4X6～20X20)●DRW-4X6●DRW-20X20

1323
1.852315◎ R series (RWW3X8～RA12X59)●RWW-3X8●RA-12X59
13559

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Sensor coils

15Features● Using high Q, stable temperature characteristicferrite coresApp. Shape, Dimension● Widely used for sensors for industrial machines● Longer sensing distance● RoHS◎ PC series (PC-5.65X1.65～36X11)●PC-11X3.2●PC-36X11

11.3

363.3

●PC-14X4

119.4

144.16