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RI-21

RI-21 Series Dry Reed Switch

RI-21 Series

Micro dry-reed switch hermetically sealed in a gas-filled  envelope. Single-pole, single-throw (SPST) type, having normally open contacts, and containing two magnetically actuated reeds.
The switch is of the double-ended type and may be actuated by an electromagnet, a  permanent magnet or a combination of both.
The device is intended for use in sensors, relays, pulse counters or similar devices.

RI-21 Series Features
u General purpose reed switch
u High breakdown voltage
u Contact layers: gold, plated ruthenium
u Superior glass-to-metal seal and blade alignment
u Excellent life expectancy and reliability

Dimensions in Inches (Millimeters)

RI-21
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Model Number

 

 

RI-21AAA

RI-21AA

RI-21A

RI-21B

RI-21C

Parameters

Test Conditions

Units

 

 

 

 

 

 

 

 

 

 

 

 

 

Operating Characteristics

 

 

 

 

 

 

 

Operate Range

 

AT

8-16

14-23

18-32

28-52

46-70

Release Range

 

AT

4-14

7.5-17.5

8-22

12-29

16-32

Operate Time - including bounce (typ.)

energization
100 AT

ms

0.1 (20 AT)

0.25 (29 AT)

0.25  (40 AT)

0.25  (65 AT)

0.25  (88 AT)

Bounce Time (typ.)

energization
100 AT

ms

0.05 (20 AT)

0.15 (29 AT)

0.15  (40 AT)

0.15  (65 AT)

0.15(88 AT)

Release Time (max)

energization
100 AT

µ s

70 (20 AT)

30 (29 AT)

30  (40 AT)

30  (65 AT)

30 (88 AT)

Resonant Frequency (typ.)

 

Hz

5500

5500

5500

5500

5500

 

 

 

 

 

 

 

 

Electrical Characteristics

 

 

 

 

 

 

 

Switched Power (max)

 

W

10

10

10

10

10

Switched Voltage DC (max)

 

V

200

200

200

200

200

Switched Voltage AC, RMS value (max)

 

V

250

250

250

250

250

Switched Current DC (max)

 

mA

250

500

500

500

500

Switched Current AC, RMS value (max)

 

mA

250

500

500

500

500

Carry Current DC; AC, RMS value (max)

 

A

1

1.5

2.5

2.5

2.75

Breakdown Voltage (min)

 

V

225

325

375

500

650

Contact Resistance (initial max)

(energization)

m W

100 (20 AT)

100 (25 AT)

100 (30AT)

100 (40 AT)

100 (40 AT)

Contact Resistance (initial typ.)

(energization)

m W

70 (20 AT)

70 (25 AT)

70 (30 AT)

70 (40 AT)

70 (40 AT)

Contact Capacitance (max)

without test coil

pF

0.3

0.3

0.25

0.25

0.25

Insulation Resistance (min)

RH £ 45%

M W

106

106

106

106

106

General data for all models RI-21

 AT-Customization / Preformed Leads
Besides the standard models, customized products can also be supplied offering the following options:
Operate and release ranges to customer specification
Cropped and/or preformed leads

Coils
All characteristics are measured using the Philips Standard Coil. For definitions of the Philips Standard Coil and the standard MIL Coil, refer to "Application Notes" in the Reed  Switch Technical & Application Information Section of this catalog.

Life expectancy and reliability
The life expectancy data given below are valid for a coil energized at 1.25 times the published maximum operate value for each type in the RI-21 series.

No load conditions (operating frequency: 100Hz)
Life expectancy : min. 108 operations with a failure rate of less than 10-9 with a confidence  level of  90%.

End of life criteria:
   Contact resistance >1W after 2 ms
   Release time > 2 ms (latching or contact sticking)

Loaded conditions (resistive load: 12 V; 4mA; (15 mA peak); operating frequency: 170 Hz)
Life expectancy: min. 107 operations with a failure rate of less than 10-8 with a confidence level of 90%.

End of life criteria:
   Contact resistance >2W after 4 ms
   Release time > 0.7 ms (latching or contact sticking)
Switching different loads involves different life expectancy and reliability data. Further information is  available on request.

Mechanical Data
Contact arrangement is normally open; lead finish is tinned; net mass is approximately 190mg; and can be mounted in any position.

Shock
The switches are tested in accordance with "IEC 68-2-27", test Ea (peak acceleration 150 G, half sinewave; duration 11 ms).  Such a shock will not cause an open switch (no  magnetic field present) to close, nor a switch kept closed by an 80 AT coil to open.

Vibration
The switches are tested in accordance with "IEC 68-2-6", test Fc (acceleration 10G; below cross-over frequency 57 to 62 Hz; amplitude 0.75 mm; frequency range 10 to 2000 Hz, duration  90 minutes).
Such a vibration will not cause an open switch (no magnetic field present) to close, nor a switch kept closed by an 80 AT coil to open.

Mechanical Strength
The robustness of the terminations is tested in accordance with "IEC 68-2-21", test Ua1 (load 40 N).

Operating and Storage Temperature
Operating ambient temperature; min: -55°C; max: +125°C.
Storage temperature; min: -55°C; max: +125°C.
Note: Temperature excursions up to 150°C may be permissible. For more information contact your nearest Coto Technology sales office.

Soldering
The switch can withstand soldering heat in accordance with "IEC 68-2-20", test Tb, method 1B:solder bath at 350 ±10°C for 3.5 ±0.5 s.  Solderability is tested in accordance with "IEC 68-2-20", test Ta, method 3: solder globule temperature 235°C; ageing 1b: 4 hours steam.

Welding
The leads can be welded.

Mounting
The leads should not be bent closer than 1 mm to the glass-to-metal seals. Stress on the seals should be avoided. Care must be taken to prevent stray magnetic fields from influencing the  operating and measuring conditions. 

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