Seiko YT57B Technical Manual

1

[SPECIFICATIONS]

Cal. No.

Item

YT57B

Movement

(x 1.0)

Additional mechanism • Automatic generating system

• Energy depletion forewarning function

• Overcharge prevention function

• Electronic circuit reset switch

• Train wheel setting device

• Date calendar

• Instant setting device for date calendar

Driving system Step motor (Load compensated driving pulse type)

Loss/gain Monthly rate at normal temperature range: less than 20 seconds
Regulation system

Nil

Measuring gate by quartz tester Use 10-second gate.
Power

supply

Automatic generating systemPower generator

PARTS CATALOGUE / TECHNICAL GUIDE

Cal. YT57B

Movement
size

Outside diameter ø27.6 mm

Casing diameter ø27.0 mm

Height 4.3 mm

Time indication 3 hands

Operating voltage range 0.45 V ~ 2.2 V
Duration of charge

From full charge to stoppage: Approx. 6 months

Jewels 6 jewels

KINETIC E.S.U. Titanium lithium ion rechargeable battery

2

PARTS CATALOGUE

Disassembling procedures Figs. : 1 → 47
Reassembling procedures Figs. : 47 → 1

Lubricating: Types of oil Oil quantity

Moebius A Normal quantity
Moebius F
SEIKO Watch Oil S-6

➡

Please see the remarks on the following pages.
Lubricating of some parts is shown in “II. REMARKS ON DISASSEMBLING AND REASSEMBLING”.

Cal. YT57B

0022 247

• Date dial guard screw (3 pcs.)

• Rechargeable battery clamp screw
(2 pcs.)

• Circuit block cover screw (2 pcs.)

• Oscillating weight bridge screw
(2 pcs.)

• Coil block screw (1 pc.)

• Train wheel bridge screw (1 pc.)

0022 490

• Oscillating weight screw (1 pc.)

1 Hour, minute and

second hands

4 0022 247

Date dial guard screw

5 0808 660

Date dial guard

8 0962 670

Intermediate wheel for
calendar correction

7 0737 670

Date corrector setting
wheel

9 0810 660

Date jumper

10 0816 670

Date driving wheel

11 0271 670

Hour wheel

6 Date dial

2 Dial

3 Holding ring for dial

3

PARTS CATALOGUE

Cal. YT57B

➡

Please see the remarks on the following pages.
Lubricating of some parts is shown in “II. REMARKS ON DISASSEMBLING AND REASSEMBLING”.

12 0022 490

Oscillating weight screw

13 0500 661

Oscillating weight

16 4225 519

Rechargeable battery clamp

15 0022 247

Rechargeable battery clamp screw

17 4216 519

Insulator for rechargeable battery

18 3023 24T

Rechargeable battery unit

19 0022 247

Circuit block cover screw

20 4457 760

Circuit block cover

21 4000 734

Circuit block

14 1002 662

Oscillating weight wheel

22 0022 247

Oscillating weight bridge screw

23 4459 500

Conductive plate

24 0198 662

Oscillating weight bridge

25 4002 514

Generating coil block

26 1002 660

Intermediate wheel for generating rotor

27 4146 518

Generating rotor

28 4239 519

Generating stator

30 4002 516

Coil block

29 0022 247

Coil block screw

4

PARTS CATALOGUE

Cal. YT57B

➡

Please see the remarks on the following pages.
Lubricating of some parts is shown in “II. REMARKS ON DISASSEMBLING AND REASSEMBLING”.

44 Winding stem

45 0282 672

Clutch wheel

46 0221 676

Center wheel and pinion

47 0100 669

Main plate

43 4239 518

Rotor stator

31 0022 247

Train wheel bridge screw

32 0125 661

Train wheel bridge

33 0391 660

Train wheel setting lever

34 4271 515

Rechargeable battery
connection (+)

35 0241 670

Fourth wheel and pinion

36 0231 530

Third wheel and pinion

37 0701 670

Fifth wheel and pinion

38 4146 531

Step rotor

39 0261 670

Minute wheel

40 0281 670

Setting wheel

41 0384 661

Yoke

42 0383 662

Setting lever