Seiko 5M42A User Manual

1
Movement size
The illustrations refer to Cal. 5M42A.
(x 1.0)
Movement
Item
[SPECIFICATIONS]
Cal. 5M42A
Cal. 5M43A
PARTS CATALOGUE / TECHNICAL GUIDE
4.3 mmHeight
Casing diameter ø27.0 mm
Capacitor voltage: 0.5 ~ 2.3V
From 1.55V to stoppage: Approx. 168 hours
Cal. No.
5M42A
5M43A
Outside diameter ø27.6 mm
3 hands
Time indication
Step motor (Load compensated driving pulse type)
Driving system
Monthly rate at normal temperature range: less than 15 seconds
Loss/gain
NilRegulation system
Use 10-second gate.
Measuring gate by quartz tester
Automatic generating systemPower generator
Polyacene lithium condenserCapacitor
Power supply
Operating voltage range
Duration of charge
6 jewelsJewels
• Automatic generating system
• Power reserve indicator
• Overcharge prevention function
• Electronic circuit reset switch
• Train wheel setting device
• Date calendar
• Day calendar (for Cal. 5M43A only)
• Instant setting device for date calendar
• Instant setting device for day calendar (for Cal. 5M43A only)
Additional mechanism

Seiko 5M42A Specifications

General

Movement	Quartz
Case Material	Stainless Steel
Crystal	Hardlex
Type	Analog
Caliber	5M42
Strap Material	Varies
Functions	Date
Bracelet Material	Stainless Steel
Dial Color	Varies (Black, White, Blue, etc.)

Summary

Technical Guide Section

Structure of the Circuit Block

Details the components and layout of the watch's circuit block.

Remarks on Disassembling and Reassembling

Provides key notes and procedures for watch component disassembly and reassembly.

Value Checking and Adjustment

Outlines procedures for checking and adjusting electrical values and performance parameters.