Reed Switch

159-157-RA1 Relay, Reed. Mercury Hg-Wetted, Form C.

The mercury-wetted contact relay represents one of the more sophisticated types of relays made today. The early pioneer work in mercury-wetted contact switching dates back to the 1950’s, as telephone laboratory scientists sought out the “perfect contact”.

Reed relays use an external electromagnet to control the reed switch. The contacts are of magnetic material and the electromagnet acts directly on them without requiring an armature to move them. Sealed in a glass tube, the contacts are protected from corrosion. Mercury-wetted relays are fast in operation and have relatively good load carrying capacity and long life. The mercury films are reestablished at each contact closure and contact erosion is eliminated. The mercury films are stretchable, there is no contact bounce and because it is a mercury contact, the contact resistance is very low and idea for low level switching applications.

A mercury-wetted reed relay is a form of reed relay that employs a mercury switch, in which the contacts are wetted with mercury. Mercury reduces the contact resistance and mitigates the associated voltage drop. For high-speed applications, the mercury eliminates contact bounce, and provides virtually instantaneous circuit closure. Mercury wetted relays are position-sensitive and must be mounted according to the manufacturer's specifications. Because of the toxicity and expense of liquid mercury, these relays have increasingly fallen into disuse.

The high speed of switching action of the mercury-wetted relay is a notable advantage. The mercury globules on each contact coalesce, and the current rise time through the contacts is generally considered to be a few picoseconds. However, in a practical circuit it may be limited by the inductance of the contacts and wiring. It was quite common, before restrictions on the use of mercury, to use a mercury-wetted relay in the laboratory as a convenient means of generating fast rise time pulses, however although the rise time may be picoseconds, the exact timing of the event is, like all other types of relay, subject to considerable jitter, possibly milliseconds, due to mechanical imperfections. The only major weakness of a mercury wetted contact relay is the necessity to mount the relay within 30° of a vertical position, due to its position sensitivity.

Type: Form C

Contacts: SPDT.

Switched Load Rating: 2 Amp, 500 Volts Max, 100 VA Maximum

Carry Load Rating: 5 Amp

Contact Resistance: 14 Milliohms Typical, 20 Milliohms Max.

Packaging: Under High Pressure in Glass Capsules.

Approximate Dimensions 5.8mm D x 38mm Long. (0.225" X 1.5")

Life Expectancy: 1 billion operations minimum at rated load.

Note: Mercury Hg-Wetted.

Danger - High Pressure Glass Capsule- Handle with Care - User assumes responsibility and competency to handle this item.

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HAMLIN - MRR-2-185 - Normally Open Magnetc Reed Switch

SPST - NO

Operating Temperature: -40°C ~ 125°C

Current – Carry: 1.5A (DC)

Voltage - Switching DC: 200 V

Operate Time: 0.75 ms

Release Time: 0.3 ms

Capacitance: 0.2 pF

Overall 2.25" Long

Switch Body 3/4"

10W 750mA (DC) Through Hole

New Old Stock

NSN 5930-01-249-7412

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Keyboard Switch.

Micro Reed & Magnet, Push Button Anti-Bounce Keyboard Switch.

Normally Open.

Snap-in Mounting.

With straight slightly slanted X shaped top and partial cap with hole for LED but NO CLEAR COVERS FOR TOPS.

Package of 4.

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Normally Closed REED Switch

Black Heat Sink Tubing Housing and White Wire Leads.

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COTO - FR2335 - Switch, Reed.

SPST-NO, Closes in Proximity to Magnet.

Glass Body 350mA, 140V

Surface-Mount

Termination Style: Gull Wing

Carry Current: 1A

Overall Length Approximately 0.75-inch, 0.085" Diameter.

Alternate: MDSM-10R-10-25 (Slightly Smaller)

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MICRO SWITCH - 20FR5-6B - Factory New Magnet Actuated Reed Proximity Switch

Normally Closed (NC) with No Nagnet Opens with magnet next to the Explosion Proof Housing

Internal dry reed switch, hermetically sealed contacts
Industrially packaged in aluminum housings
Matching permanent magnet unit
1/2 inch conduit outlet
Meets portions of NEMA enclosure Type 1, general purpose; Type 2, driptight; Type 3, weather resistant; and, Type 12, industrial Use
Slide-by, head-on or vane actuation
Designed to be compatible with solid state logic level input requirements

Voltage: 500VDC Max, 1.5Amp Max

20 Watt Max.

SPST Relay Contact

Factory New Old Stock - In Manufacturer's Packaging with Instructions and Bracket.

Made in USA

Note: This product was oroginally branded labeled Honeywell, Microswitch, later Yamatake, Pepperl+Fuchs, Visolux, or Azbil.

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Hasco - P1291-12 Switch, Magnetic Reed.

A reed switch is a passive device consisting of two Reed Blades sealed inside a glass tube with an Inert Gas, which operates when brought near a magnetic field.

The reeds are hermetically sealed in cantilever form so that their free ends overlap and are separated by a small air gap. The contact area of each blade can be coated with one of many types of contact materials such as Ruthenium, Rhodium, Tungsten, Silver, Irridium, Molybdenum etc.

Due to the low inertia of the Reed Blades and the small gap, fast operation is achieved. The inert gas inside the sealed Reed Switch not only prevents oxidation of the contact material but also helps in making it one of the few devices that can be used in explosive environments.

Normally Open.

Package: Glass Envelope.

Dimensions: 0.7" (1.7mm) D x 0.377" (9.5mm) long.

New Old Stock

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Switch, pushbutton. Contacts: SPST NO. Contact Ratings: 100VDC 100mA 10 watt (max) resistive only. Actuator: momentary. Connection: Two (2) turret post connections. Mech: Panel mount. Body: Approximately 0.530" D x 0.566" deep, behind panel. Hermetically sealed. Note: Small red actuator. No actual knob as seen in Alco MSPM-101CSDX. Magnetic reed switch. Learn More

Switch, reed. Normally open. Package: Glass envelope, 2.6mm D x 15.8mm long. Note: Hexagram D-1348-05. Hasco ALT P/N: 032-0003. Learn More

HAMLIN - MDRR-4-1722 - Reed Switch Glass Capsule, Two Ferromagnetic Nickel-Iron Wires.

The two wires are formed into "reeds" by flattening one end. The reed ends are carefully aligned with a small overlap and then permanently sealed inside the glass capsule. The overlap or contact area of the reeds is coated with special metals such as ruthenium. The nickel-iron leads are tin plated so that they can be soldered.

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 micro-controller logic level loads

A miniature changeover switch with a 14.73mm long x 2.54mm diameter (0.580" x 0.100") glass envelope. 

The Reed Body Measures 0.580" Long. 0.100" Diameter Length with leads is Approximately 1.60" Long

Note: Hamlin Products are now Littelfuse products.

Note: Price is for 1 Glass Reed Switch

Applications:

• Position sensing
• Industrial controls
• Office equipment
• Home appliances

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MICRO SWITCH - 20FR5-6 - NEW REED SWITCH SP

Magnetic Reed Sensor Magnetic Field Sensing

N.C. 500V 1.5A 20W

16-Ga

Hermetically Enclosed

Wire Leads

New Old Stock - No Box or Mounting Brackets  

Proudly Made in USA

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Switch, reed. Magnetic. Head: 0.352' x 0.273" oval. Overall head length: 1.076" long. New. Complete with attached 17" - 3 conductor solid wire leads (Red/Black/White). Note: Marked W0207, and W0407. Learn More

Meder Electronics - KSK-1A71/4-BV50822 - Switch, Magnetic Reed.

A reed switch is a passive device consisting of two Reed Blades sealed inside a glass tube with an Inert Gas, which operates when brought near a magnetic field.

The reeds are hermetically sealed in cantilever form so that their free ends overlap and are separated by a small air gap. The contact area of each blade can be coated with one of many types of contact materials such as Ruthenium, Rhodium, Tungsten, Silver, Irridium, Molybdenum etc.

Due to the low inertia of the Reed Blades and the small gap, fast operation is achieved. The inert gas inside the sealed Reed Switch not only prevents oxidation of the contact material but also helps in making it one of the few devices that can be used in explosive environments.

Note: Standex Electronics' reed switch-based solutions include Meder, Standex, and Kofu (formerly OKI) brand reed switches.

Status: Discontinued

Current Rating: 1Amp

Contact: Normally Open 1 Form A Contact

Case: Gass Envelope.

Dimensions: 0.1" Diameter x 0.625" Long.

New Old Stock

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MEDER ELECTRONICS - KSK-1A71/7- BV143 - Switch, Reed.

Status: Discontinued

Glass length of 16.5 mm and diameter of 2.8 mm
Normally open 1 Form A contact
Carry current up to 1 A
300 VAC breakdown voltage

NO Magnetic. Glass.

Dimensions: 1.7mm D x 12.7mm long.

Overall with full leads 1.809" (45.9mm) long.

Alternate/Equivalent: ORD2210V-2025

Note: In 2012, Meder underwent global expansion through its merger with market-listed Standex Electronics. Today, the two companies operate together as Standex-Meder Electronics, and the Meder group is established in Europe, the USA and Asia.

 

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