Reed contact

Good electrical connection is through the contact of two overlapping parts coated with a thick layer of nonmagnetic metal, low resistivity of silver than the corrosion resistance of gold is more suitable for as a coating material [1]. There are also using mercury wetted tube, wet spring tube contact must be installed in pairs. Two spring wire made of nickel/iron, nickel and iron alloy of nickel (52%). Affected by magnetic field of magnetic reed fuses must be ferromagnetic.Three of the most popular material properties, easy annealing ferromagnetic: iron, cobalt and nickel. Two is the tip of the reed contacts or sputtering plating rhodium, ruthenium or iridium.

Glass sealing

Used for glass tube outer packaging, its temperature coefficient of expansion (TCE) exactly match NiFe alloy. At both ends of the glass tube is heated and glass melting, form a gas-tight seal on both ends of the cover.In the process of glass sealing glass cavity is usually filled with inert gas (usually nitrogen) or cavity, may create a vacuum, vacuum. The vacuum is usually support high voltage switch (more than 1000 volts)

Specification

• Part No. : MKA-16101
• Total Length : 44.7 mm
• Glass Length : 16.5 mm
• Glass Diameter : 2.54 mm
• Contact Form : 1A(SPST-NO)
• Contact Position : SYM
• Contact Material : Ru
• Contact Rating : 10W
• Max. Switching Voltage : 100 VDC / VAC
• Max. Switching Current : 0.5A
• Contact Resistance : (at initial value)100 mOhms
• Pull In Value (AT) : 10-35
• Drop Out Value (AT) : 5
• Operation Time : 1.0 mSec.(Max.)
• Release Time : 0.4 mSec.(Max.)
• Breakdown Voltage : 220 VDC
• Contact Capacitance : 0.3 pF
• Insulation Resistance : 109Ohms
• Resonant Frequency : 3 kHz
• Operation Temperature : -60Degree~+125Degree
• High Humidity : 98% (Max.)
• Operation Frequency : 400Hz

Characteristics

• Disconnect (PI, Pull In) close to the magnetic reed switch contact
• Absorption (DO, Drop Out) is the magnetic reed switch contact point
• Most companies measure ampere turns (AT) the reed switch

Advantages

• The advantages of the dry reed pipe [2] is its small volume, light weight, which makes them easy to install and inconspicuous. Because of operating switch volume is small, so without complex CAM or crank, so there will be no metal fatigue phenomenon, ensure the almost unlimited service life. And can be installed in the limited space, it is very suitable for use in a tiny device. The magnetic reed switch and suitable magnet prices are cheap and readily available. Dry reed pipe of the main switch is a kind of non-contact seal.
• Magnetic reed switch switch components are sealed in an inert gas, no contact with the external environment, thus greatly reducing the contact in the process of opening and closing due to contact spark contact oxidation and carbonization. And to prevent the steam and dust impurities such as junctions, erosion. Long working life.
• Reed thin, short, have higher natural frequency, increase the speed of the contact on and off, the switch speed than the average electromagnetic relay 5 ~ 10 times faster.

Disadvantages

• First of all, contact and reed is quite small and delicate, so they are difficult to bear high pressure and large current. Current is too large, the reed will lose elasticity due to overheating. The switch capacity is small, jitter caused by contact and contact contact resistance.

• Dry reed pipe have voltage and current rating. Although power W = I * current voltage U, the same power may be composed of different voltage and current are combined. Remember that not more than rated current. For example, 10 v * 1 a = 10 w, 1 v * 10 a = 10 w at the same time, in the second case, the current will be too big. If you want to use large current, composed of a relay coil and magnetic reed switch relay circuit is a more appropriate choice