Epson SOLAR Series Guide

Watch Movement Specification and Drawing
SOLAR SERIES
Cal. VS72A
Movement Size
Casing Diameter
Height
Running Time
12’’’
Ø 27.0mm
4.40mm
Approx. 6 months

Date: 24/Sep./'19
Cal. VS72A
Items Rev. Page
Features 01 1
Specifications 03 2
Appearance 04 3
Casing 02 4
Hand fitting 02 5
Hand setting stem 01 6
Dial 01 7
Solar cell unit 02 8
Attention-01 02 9-01
Attention-02 03 9-02
Attention-03 01 9-03
Operation-01 01 10-01
Operation-02 01 10-02

Date :
1.Solar-powered watch
2. Eliminating the need for battery replacement
3. You can use the dial which light transmittance is more than 30%
It is possible to assemble the dial which transmits light on the solar cell.
It enabled to cover the solar cell color, and you can design variety colors of dials.
4. Running time
Expected running time from full charge to stoppage will be around 6 months.
5. Power depletion warning function
The two-second intervals movement of the second hand is a signal of energy depletion.
The watch continuous running time after two-second intervals movement is approximately 1 week.
6. Over charge prevent function is equipped
7. Structure of the separated parts
If the secondary battery is charged more than predetermined voltage, over charge prevent function is
operated to prevent the secondary battery deterioration and breakage.
This watch is a solar-powered watch containing a solar cell underneath the dial to convert any form of
light into '' electrical energy'' and store the power in a secondary battery.
Cal. VS72A Features 24/Apr./'15
Rev. : 01
Unlike conventional quartz watches, this watch does not use a silver oxide battery, thus eliminating the
need for battery replacement.
Solar cell unit
Solar cell lead terminal
Movement
Hand setting stem
Solar cell
Dial support ring
Secondary battery unit
Untransparent plate
P. 1

Date :
1. MOVEMENT DIMENSIONS
Outside diameter
φ
27.60mm(12H-6H)
×
24.00mm(3H-9H)
Casing diameter
φ
27.00mm(12H-6H)
Total height
4.4mm
2. TIME STANDARD
Type of quartz oscillator
Tuning fork
Frequency of quartz oscillator
32,768 Hz
Accuracy
±
20 seconds per month (on wrist)
Operating temperature range
−
5
℃
to
＋
50
℃
Regulation device
Nil (Pre-adjusted)
3. INDICATOR / FUNCTIONS
3 Hands
Hour / Minute / 1/5 second chronograph (Center)
Small hands
Alarm hour and minute (6H) / Small second (9H)
Minute chronograph (12H)
Calendar
Instant setting device for date calendar
Reset switch
Power depletion warning function (BLD)
(Second hand moves at 2-second intervals when voltage is 1.2V)
Alarm
Chronograph
Running time
Approx. 6 months (After fully charged)
4. FEATURES
Jewels
0 Jewels
Anti-magnetism
Over 1600A/m (Direct current magnetic field)
Driving current consumption
Approx. 0.65
μ
A (1.35V , Chronograph non-operates)
Operation stopping voltage
1.0V
Solar cell type
Amorphous silicon solar cell
Maximum unbalance of hands
Small second hand
: 0.03
μ
N
・
m
Minute chronograph / Alarm minute hand
: 0.03
μ
N
・
m
Alarm hour hand
: 0.025
μ
N
・
m
1/5 second chronograph hand
: 0.09
μ
N
・
m
Minute hand
: 0.70
μ
N
・
m
Moment of inertia
1/5 second chronograph hand
: less than 0.12
μ
g
・
m²
5. SECONDARY BATTERY
Type
Titanium-lithium-ion secondary battery
Size
φ
9.5
×
t 2.05 mm
Capacity
5mAh
Nominal voltage
1.5V
6. SEPARATED PARTS (Parts code)
Hand setting stem
0351587
Secondary battery unit
302334T
Solar cell unit
4020551
Solar cell lead terminal ( 2 pcs )
4281516
Untransparent plate
4453500
Piezoelectric element
4589801
7. TEST OF ACCURACY
Equipment to be used
SEIKO quartz tester QT-99
Greiner quartz timer-C , Witschi Q-tester 4000
Duration of measurement
10 seconds
Microphone to be used
Electromagnetic detection type
All specifications are subject to change without notice.
Solar Analog Quartz 12''' Center Second Chronograph Movement
Cal.
Rev. : 03
1/Sep./'15
VS72A Specifications
The chronograph can measure up to 60 minutes in 1/5 second
increments.
P. 2