DIMENSIONS
in Inches (Millimeters)
3500 Series Low Thermal EMF Reed Relays
e 3500 Series is ideally suited to the needs of Instrumentation, Data Acquisition and
Process Control. e specication tables allow you to select the appropriate relay for
your particular application. Recommended for use in high accuracy DVM’s, Multi-
plexers and Digital or Analog Multipoint Recorders. If your requirements dier from
the selection options, please consult Coto’s Factory to discuss a custom reed relay.
3500 Series Features
u
Low ermal EMF: < 10 µV through < 0.5 µV with 50 nV stability
u
Patented Low ermal Design. U.S. Patent #4,084,142
u
Low power coils to ensure low thermal EMF
u
High Insulation Resistance - 10
12
Ω
u
Control/Signal isolation of 1500 VDC
u
High reliability, hermetically sealed contacts
u
Form A, Dry or Hg Wetted contacts. High Dielectric Strength
u
Epoxy coated steel shell provides magnetic shielding
u
RoHS compliant (except for 3520)
3500 SERIES/LOW THERMAL EMF REED RELAYS
1.00 .050
.485 MAX
.200
.300
(5.08)
(7.62)
(1.27)
(12.32)
(0.66)
(25.4)
.026 DIA.
.125
(3.17)
.500
(12.7)
12
14
13
1.20
(30.48)
.050
(1.27)
.100
.100
(2.54)
(2.54)
.500
(12.7)
.485 MAX
(12.32)
Ordering Information
Part Number XXXX XX X--1X
Model Number
3501 3502 3520 3540 3541
Coil Voltage
05=5 volts
12=12 volts
Shielding Options2
1=Electrostatic Shield
Thermal EMF Rating
See available ratings in specification table.
1=<10µV Hg Wetted Only
9=<5µV Dry or Wetted
8=<3µV Dry Only
7=<1µV Dry Only
5=<0.5µV Dry Only
Bottom View
For Model
3502, 3520 & 3541
For Model
3501 & 3540
tel: (401) 943.2686 | fax: (401) 942.0920
20 | page
Notes:
1 Consult factory for life expectancy at other switching loads.
2 Models 3501 and 3540, optional electrostatic shield is tied to pin #5.
Models 3502, 3520 and 3541, optional electrostatic shield is tied to pin #13.
3 Model 3520 has Hg wetted contacts - position sensitive, must be mounted within 30° of vertical plane. See schematic. Hg content per cap-
sule: Form A, 0.04 grams.
Environmental Ratings:
Storage Temp: -35°C to +100°C; Operating Temp: -20°C to +85°C; Solder Temp: 270°C max; 10 sec. max
All electrical parameters measured at 25°C unless otherwise specied.
Vibration: 20 G’s to 2000 Hz; Shock: 50 G’s
MODEL NUMBER 350123502235202,3 3540235412
Parameters Test Conditions Units
1 Form A
2 Form A 1 Form A
Hg Wetted
1 Form A
High Voltage
2 Form A
High Voltage
Thermal EMF Options
Measured after
5 minutes at nominal
coil voltage
(Refer to Reed Relay
Technical Section for details)
µV
Individual
<5µV
<3µV
<1µV
<0.5µV
Differential
<5µV
<3µV
<1µV
<0.5µV
Differential
<10µV
<5µV
-
-
Individual
<5µV
<3µV
-
-
Differential
<5µV
<3µV
-
-
COIL SPECS.
Nom. Coil Voltage VDC 512 512 512 512 512
Coil Resistance +/- 10%, 25° C Ω350 2000 350 2000 200 850 250 1500 250 1500
Operate Voltage Must Operate by VDC - Max. 3.8 9.0 3.8 9.0 3.8 9.0 3.8 9.0 3.8 9.0
Release Voltage Must Release by VDC - Min. 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0 0.4 1.0
CONTACT RATINGS
Switching Voltage Max DC/Peak AC Resist. Volts 200 200 500 500 500
Switching Current Max DC/Peak AC Resist. Amps 0.5 0.5 1.0 0.5 0.5
Carry Current Max DC/Peak AC Resist. Amps 1.5 1.5 2.0 2.0 2.0
Contact Rating Max DC/Peak AC Resist. Watts 10 10 28 10 10
Life Expectancy-Typical1Signal Level 1.0V, 10mA x 106 Ops. 500 100 1000 100 100
Static Contact
Resistance (max. init.) 50mV, 10mA Ω0.200 0.100 0.050 0.200 0.100
Dynamic Contact
Resistance (max. init.)
0.5V, 50mA
at 100 Hz, 1.5 msec Ω0.300 0.200 0.100 0.300 0.200
RELAY SPECIFICATIONS
Insulation Resistance
(minimum)
Between all Isolated Pins
at 100V, 25°C, 40% RH Ω1012 1012 1012 1012 1012
Capacitance - Typical
Across Open Contacts
No Shield
Shield Guarding
pF
pF
3.0
1.9
1.7
0.2
1.7
0.2
3.0
1.9
1.7
0.2
Dielectric Strength
(minimum)
Between Contacts
Contacts to Shield
Contacts/Shield to Coil
VDC /peak AC
VDC/peak AC
VDC/peak AC
700
1000
1500
350
1000
1500
1000
1000
1500
1500
1000
1500
1500
1000
1500
Operate Time - including
bounce - Typical
At Nominal Coil Voltage,
30 Hz Square Wave msec. 0.75 0.75 2.0 1.0 1.0
Release Time - Typical msec. 0.1 0.1 1.0 0.2 0.2
Top View4:
Dot stamped on top of relay refers to pin #1 location
Grid = .1”x.1” (2.54mm x 2.54mm)
113 59
2
6
10
UP
113
4
12
5
113
4
12
5113 59
2
6
10
113 59
2
6
10
COTO TECHNOLOGY, INC.
For most recent data visit www.cotorelay.com page | 21