littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
MDRR-DT 14.7mm Miniature Changeover Reed Switch
Description
The MDRR-DT Reed Switch is a miniature changeover switch with a 14.73mm
long x 2.54mm diameter (0.580” x 0.100”) glass envelope, capable of switching
175Vdc at 5W. It has insulation resistance of 109 ohms minimum, and contact
resistance less than 100 milli-ohms. The MDRR-DT is available in surface mount
version, that is, MDSM-DT.
Agency Approvals
Agency Agency File Number Ampere-Turns Range
E47258
E471070 10-30 AT
DEMKO 14 ATEX 1393U 10-30 AT
Switch Type
Contact Form C (SPDT-CO)
Materials Body: Glass
Leads: Tin-plated Ni-Fe wire
Axial Lead Reed Switches
Features
• Miniature SPDT changeover switch
• Capable of switching 175Vdc or
0.25A at up to 5W
• Available sensitivity range
10-30 AT
Benefits
• Hermetically sealed switch
contacts are not affected by and
have no effect on their external
environment
• Can be used as changeover or
normally closed contact
• Zero operating power required for
contact closure
• Excellent for switching
microcontroller logic level loads
Applications
• Position Sensing
• Reed Relays
• Industrial Controls
• Office Equipments
• Home Appliances
• Security
Dimensions
Dimensions in mm (inch)
Low Power > MDRR-DT
RoHS
Note: SPDT-CO = Single-Pole, Double-Throw, Change Over
Electrical Ratings
Contact Rating 1
W/VA - max. 5
Voltage 3
Switching 2
Breakdown 4
Vdc - max.
Vac - max.
Vdc - min.
175
120
200
Current 3
Switching 2
Carry
Adc - max.
Aac - max.
Adc - max.
0.25
0.18
1.50
Resistance Contact, Initial
Insulation
Ω - max.
Ω - min.
0.100
109
Capacitance Contact pF - typ. 1
Temperature Operating
Storage 5
°C
°C
-40 to +125
-65 to +125
Notes:
1. Contact rating - Product of the switching voltage and current should never exceed the wattage rating. Contact Littelfuse for additional load/life information.
2. When switching inductive and/or capacitive loads, the effects of transient voltages and/or currents should be considered. Refer to Application Notes AN108A and AN107 for details.
3. Electrical Load Life Expectancy - Contact Littelfuse with voltage, current values along with type of load.
4. Breakdown Voltage - per MIL-STD-202, Method 301.
5. Storage Temperature - Long time exposure at elevated temperature may degrade solderability of the leads.
F - Formed
COMMON
N.O.
N.C.
N.O.
N.C.
0.20 (.008) MIN.
2XØ0.56 REF.
(.022)
Ø0.51 REF.
(.020)
AT 1.6 FROM SEAL
CL OF OVERLAP
28.32 REF.
(1.115)
2.54 MAX.
(.100)
17.78 MIN.
(.700)
51.66 REF.
(2.034)
52.48 REF.
(2.066)
0.80 REF.
(.031)
14.73 MAX.
(.580)
4.57 REF.
(.180)
2.54 REF
. (.100)
1.57 (.062) REF.
0.55 (.022) MAX.
U - Unformed
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
Drop-Out vs. Pull-In Chart
Packaging
Packaging Option Packaging Specification Quantity Quantity and Packaging Code Taping Width
Bulk Bulk 1000 N/A N/A
Product Characteristics
Operating Characteristics
Operate Time 10.7ms - max.
Release Time 11ms - max.
Shock 211ms 1∕2 sine wave 50G - max.
Vibration 250-2000 Hertz 30G - max.
Resonant Frequency 11.0kHz - typ.
Part Numbering System
Notes:
1. Operate (including bounce)/Release Time - per EIA/NARM RS-421-A,diode suppressed coil (Coil II).
2. Shock and Vibration - per EIA/NARM RS-421-A and MIL-STD-202.
3. Pull-In Range - Contact Littelfuse for narrower AT ranges available.
4. Rating Sensitivity - The value at which contact ratings and operating characteristics are determined. Derating may be required below this value.
5. Custom modifications of forming and/or cutting of reed switches are available. Please contact Littelfuse.
Axial Lead Reed Switches
Low Power > MDRR-DT
MDRR-DT 14.7mm Miniature Changeover Reed Switch
MDRR-DT -15-20 F
Series
AT Range
10-15 AT
10-20 AT
15-20 AT
15-25 AT
15-30 AT
20-25 AT
20-30 AT
20-35 AT
25-30 AT
Version
F = FORMED
U = UNFORMED
Example:
15-20 AT product is
MDRR-DT-15-20-F or
MDRR-DT-15-20-U
Note: Chart represents the range of Drop-Out, min to max for a given Pull-In value.
Note: These AT values are the before-modification values of the bare reed switch.
Magnetic Characteristics
Pull-In Range 3Ampere Turns 10-30
Rating Sensitivity 4Ampere Turns 20
Test Coil L4989
Additional Information
Datasheet Samples
Resources
5
0
10
15
20
25
50
Pull-In (AT, L4989 Coil)
Drop-Out (AT, L4989 Coil)
10 15 20 25 30
35
Max.
Min.
littelfuse.com© 2015 Littelfuse
Specifications are subject to change without notice.
Surface Mount Reed Switches
Low Power > MASM-14
