littelfuse.com© 2015 Littelfuse Revised: 11/02/15
Specifications are subject to change without notice.
DRT-DTH 39.7mm Standard Changeover Reed Switch
Description
The DRT-DTH Reed Switch is a standard changeover switch with a 39.67mm long
x 5.33mm diameter (1.562” x 0.210”) glass envelope, with tungsten contacts
capable of high voltage and power switching up to 500Vdc at 50W. It has the
insulation resistance of 10
9
ohms minimum and contact resistance less than
500 milli-ohms.
Switch Type
Contact Form C (SPDT-CO)
Materials
Body: Glass
Leads: Tin-plated Ni-Fe wire
Axial Lead Reed Switches
Features
• Changeover switch
• Capable of switching 500Vdc or
1.5A at up to 50W
• Minimum voltage breakdown
1000Vdc
• Available sensitivity range
50-80 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
• Capable of switching European
mains voltage
• Zero operating power required for
contact closure
Applications
• Security
• Limit switching
• Industrial safety applications
• White goods applications
Dimensions
Dimensions in mm (inch)
High Power > DRT-DTH
RoHS
Electrical Ratings
Contact Rating
1
W/VA - max.
50
Voltage
3
Switching
2
Breakdown
4
Vdc - max.
Vac - max.
Vdc - min.
500
350
1000
Current
3
Switching
2
Carry
Adc - max.
Aac - max.
Adc - max.
1.5
1.0
2.0
Resistance
Contact, Initial
Insulation
Ω - max.
Ω - min.
0.500
6
10
9
Capacitance Contact pF - typ. 2.0
Temperature
Operating
Storage
5
°C
°C
-20 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.
6. Contact resistance measured at 36Vdc, 100mA, switched wet.
7. Not recommended for small electrical loads.
1.83
(.072) NOM.
25.40
(1.000) NOM.
12.45
(.490) NOM.
38.10 - 39.67
(1.500) NOM. - (1.562) MAX.
85.73 - 84.14
(3.375) NOM. - (3.3125) MIN.
0.25
(.010) NOM.
CL OF OVERLAP
5.54
(.218) MAX.
27.66
(1.89) REF.
5.33
(.210) MAX.
1.02
(.040) DIA. REF.
1.27
(.050) DIA. REF.
Note: SPDT-CO = Single-Pole, Double-Throw, Change Over
