Reed Switches. Standard & Miniature Switches. Sub Miniature & Tiny Switches. Changeover Switches. Reed Operating Coils. Standard & Miniature coils

Size: px

Start display at page:

Download "Reed Switches. Standard & Miniature Switches. Sub Miniature & Tiny Switches. Changeover Switches. Reed Operating Coils. Standard & Miniature coils"

William Barrett
5 years ago
Views:

1 Reed witch selector guide "our aim is to form close partnerships with our customers, working with them at all levels" Reed witches tandard & Miniature witches ub Miniature & Tin witches hangeover witches Reed Operating oils tandard & Miniature coils Permanent Magnets for Reed witch Operation Magnet Tpes Operating Distances Reed witch Application otes ontact Protection Page R G I D R T UKA QUALITY MAAGMT 003 FM02050 For all our sales enquiries call... UK +44 (01202) pecification subject to change without notice rdom UA + 1 (619)

current switching. Parameters Tpe DRA200G DRA282G DRA283 DRA500H DTA500H DTA810H MRA560G ontact form A A A A A A A ontact material Rh Rh Rh Rh T T Rh witching capacit max.

2 2 ontrolled switching environment. Low contact resistance variants. High power applications. High voltage. Reed witch tandard & Miniature witches A famil of form 'A' reed switches produced with Rhodium contact material, designed to range from moderate currents and voltages through to high voltage, high current switching. Parameters Tpe DRA200G DRA282G DRA283 DRA500H DTA500H DTA810H MRA560G ontact form A A A A A A A ontact material Rh Rh Rh Rh T T Rh witching capacit max. W/VA witching voltage max. V A/D witching current max. A 1.3 *3.0 * arring current max. A Dielectric strength min. VD Initial ontact resistance max. mohms Insulation resistance min. Ohms Operate sensitivit range AT Release sensitivit min. AT Operate time including bounce max. ms Bounce time max. ms Release time max. ms Resonant frequenc tp. Hz Operating frequenc max. Hz Vibration 35 g Hz hock 11ms g apacitance tp. pf Operating temperature range / Dimensions tandard tandard size ormall Open High Power High Voltage Miniature Overall length A max. mm Glass length B max. mm Glass diameter max. mm Wire diameter D nom. mm 2.5x x x x x x OTAT U OW UITD KIGDOM T F W +44 (0) (0) ics@crdom.com * Reduced life at high current. Plus Glass Pip 5.9 max. A B D UA T F sales@crdom.com W standard & miniature Reed witches

ub-miniature ormall Open ORMALLY OP Ver Tin Parameters Tpe RA200G RA258 RA260G TRA211G TRA291G TRA294G VDA200H ontact form A A A A *A A A ontact material Rh Rh Rh Rh Rh Rh Durel witching capacit max.

3 Reed witch ub Miniature & Tin witches Form A These tin reed switches are designed for low power and high speed switching with maximum sensitivit. Their extremel small size make them ideal for Dual In Line packages, or operation. Form A mall phsical size. entre or offset contact configurations. High speed switching. ub-miniature ormall Open ORMALLY OP Ver Tin Parameters Tpe RA200G RA258 RA260G TRA211G TRA291G TRA294G VDA200H ontact form A A A A *A A A ontact material Rh Rh Rh Rh Rh Rh Durel witching capacit max. W/VA witching voltage max. VA/D witching current max. A arring current max. A Dielectric strength min. VD Initial ontact resistance max. mohms Insulation resistance min. ohms Operate sensitivit range AT Release sensitivit min. AT Operate time including bounce max. ms Bounce time max. ms Release time max. ms Resonant frequenc tp. Hz 2,900 2,900 4,200 7, ,000 - Operating frequenc max. Hz Vibration 35 g Hz 2,000 2,000 2,000 2,000-2,000 - hock 11ms g apacitance tp. pf Operating temperature range Dimensions Total length Glass length Glass diameter Wire diameter * Offset ontact onfiguration Tin ize ormall Open A max. mm B max. mm max. mm D nom. mm x A B D sub miniature & tin Reed witches

4 4 hangeover or normall application. Inert gas atmosphere. Reed witch hangeover witches A famil of form '' reed switches offers moderate to medium voltage breakdown. tandard ompact hange Over High Power Tin hange Over OTAT U OW UITD KIGDOM T F W +44 (0) (0) ics@crdom.com UA T F sales@crdom.com W Parameters Tpe R200H R500H T500H TR200B TR200 ontact form ontact material Rh Rh T Rh Rh witching capacit max. W/VA # 5 5 witching voltage max. V A/D witching current max. A arring current max. A Dielectric strength min. VD Initial contact resistance max. mohms Insulation resistance min. ohms Operate sensitivit range AT Release sensitivit min. AT Operate time without bounce max. ms Bounce time max. ms Release time max. ms Resonant frequenc tp. Hz Operating frequenc max. Hz Vibration 35 g Hz g@50-2k Hz 30g@50-2k Hz hock 11 ms g apacitance tp. pf Operating temperature range / /+125 Dimensions Overall length A max. mm Glass length B max. mm Glass diameter max. mm Wire diameter D max. mm ompact hange Over A B D Tin hange Over Optional ranked Leadout on.o. ide (TR200B) changeover Reed witches A B D

5 Reed Operating oils Operating coils for tandard and Miniature size reed switches are available for customer assembl of Reed Relas. oils are made in two widths to take wither one or two reed switches. rdom Magnetics specialise in producing custom designs, so other variations and options ma be available to suit particular requirements. Details of rdom Magnetics Reed witches are listed on separate sheets, available on request. 5 Miniature tandard 12.7 'W' 12.7 'W' pin centres 28.7 Dimensions in mm. 1.1 dia pins can be placed on a 2.54 grid. ee footprint drawing Pin centres dia pins can be placed on a 2.54 grid. ee footprint drawing oil oil Footprint Tpe M Voltage Resistance View from top M05 5Vdc 155 Ohms M12 12 Vdc 930 Ohms M24 24 Vdc 3500 Ohms MD05 5Vdc 78 Ohms MD12 12 Vdc 435 Ohms MD24 24 Vdc 1875 Ohms oil oil Footprint Tpe Voltage Resistance View from top 05 5Vdc 120 Ohms Vdc 635 Ohms Vdc 3100 Ohms D05 5Vdc 48 Ohms D12 12 Vdc 400 Ohms D24 24 Vdc 1455 Ohms oil o. of Rx W H size reeds ensitivit M MD oil o. of Rx W H size reeds ensitivit D Part umber sstem Rela Tpe M = Miniature = tandard M 05 Bobbin size = single D = double oil Voltage reed operating coils

6 6 Permanent Magnets for Reed witch Operation A range of s is available for operating the rdom Magnetics range of reed switches. The selection of the correct combination of s and reeds switches, for a particular application, will normall be made on an empirical basis as intricate calculations are not necessar. The following table of tpes and accompaning graphs act as a guide to the relationship between switch sensitivit and tpe. These figures can onl be taken as a rough indication, due to the fact that s are manufactured to commercial tolerances. Details of rdom Magnetics Reed witches are listed on separate sheets, available on request. Magnet Tpes Tpe ominal Dimensions mm/ins Total Magnetic umber Length 'A' Length 'B' Length '' Flux mm inches mm inches mm inches µwb RH RH RH RH RH RH Diameter RH Diameter All of these s are polarised along their length. 'A' 'B' dia. 'A' 'B' '' 'YLIDRIAL' 'BAR' OTAT U OW UITD KIGDOM T F W +44 (0) (0) ics@crdom.com Actuation of Reed witches with a Permanent Magnet Direct Actuation: A moved perpendicularl towards and awa from a Reed witch turns it on and off once. A moved parallel to a Reed witch operates it from one to three times. A swung towards and awa from a Reed witch operates it once. A ring moved parallel to the Reed witch axis operates it from one to three times. ring Rotation: xamples of switching through rotational movement: Indirect Actuation: hielding With the stationar arrangement of a Reed witch and, the reed contact s are. hould the ic field be diverted awa from the Reed witch b a shield of ferro-ic material placed between the switch and the, the contacts will. When the shield is removed, the reed contact s become icall actuated and close. ic shield UA T F W sales@crdom.com permanent s for Reed witch operation

7 Operating graphs for Direct Actuation B Magnet parallel to reed switch and moving in perpendicular direction. Distance is between outside of reed switch and face of. Rating of switch in ampere-turns Miniature size switches RH01 RH33 RH32 RH34 43µWb RH74 4µWb 9µWb 22µWb 30µWb 71µWb (1.0) (2.0) (3.0) (4.0) Pull-in distance in mm (inches) 120 tandard size switches Rating of switch in ampere-turns RH01 RH33 RH32 RH34 43µWb RH74 4µWb 9µWb 22µWb 30µWb 71µWb (1.0) (2.0) (3.0) (4.0) Pull-in distance in mm (inches) permanent s for Reed witch operation

8 8 Reed witch Application otes ontact Protection OTAT U OW UITD KIGDOM T F W +44 (0) (0) ics@crdom.com UA T F sales@crdom.com W apacitor in F 1 0,8 0,6 0,4 0,2 0,1 0,08 0,06 0,04 0,02 0,01 0,008 0,006 0,004 0,002 0, ,8 0,4 0,2 0,1 I 0,08 0,06 0,04 0,02 0,01 urrent in A The upper nomograph can be used for determining contact arc suppression for inductive loads. xample 1: I = 0,1 A V = 230 V = 0,001 microfarads R = 340 ohms xample 2: If the current inrush is critical use the lower nomograph to determine the minimum resistance. I = 0,5 A Rmin = 400 ohms 0, Load voltage in V xample 1 max. current inrush A 10 A 5 A 2 A 1 A 0,5 A Load voltage V V 200 V 100 V 50 V 25 V 10 V R R xample 2 I R Ω Resistance in Load

9 Reed witch Application otes apacitive Loads Unlike inductive loads, capacitive and lamp loads are prone to high inrush currents which can lead to fault operation and even contact welding. When switching charged capacitors (including cable capacitance) a sudden unloading can occur, the intensit of which is determined b the capacit and length of the connecting leads to the switch. This inrush peak can be reduced b a series of resistors. The value of these resistors is dependent on the particular application but should be as high as possible to ensure that the inrush current is within the allowable limits. When cutting or bending Reed witches, it is important that the glass bod is not damaged. Therefore, the cutting or bending point should be no closer than 3 mm to the glass bod and the leads should be supported when cutting or bending as shown. utting Bending 9 The diagram illustrates a resistor/capacitor network for protecting a Reed witch against high inrush currents. R1 and/or R2 are used depending upon circuit conditions. able R1 R V Load R2 Actuation of Reed witches with a Permanent Magnet xamples of switching with the use of a moving Direct Actuation: A moved perpendicularl towards and awa from a Reed witch turns it on and off once. With lamp load applications it is important to note that cold lamp filaments have a resistance 10 times smaller than alread glowing filaments. This means that when being turned-on, the lamp filament experiences a current flow 10 times greater than when alread hot. This high inrush current can be reduced to an acceptable level through the use of a series of currentlimiting resistors. Another possibilit is to fit a resistor across the switch. This allows just enough current to flow through the filament to keep it warm, et not enough to make it glow. R A moved parallel to a Reed witch operates it from one to three times. A swung towards and awa from a Reed witch operates it once. R R1 R2 V Lamp V Lamp A ring moved parallel to the Reed witches axis operates it from one to three times. ring Lamp load with parallel or current limiting resistor across the switch Rotation: xamples of switching through rotational movement: utting and Bending As the Reed witch blades form part of a ic circuit, shortening the leads results in increased pull-in and drop-out values. AT increase in % Pull-in and drop-out sensitivit xample Drop-out Pull-in ut-off length in mm Indirect Actuation: hielding With the stationar arrangement of a Reed witch and, the reed contact s are. hould the ic field be diverted awa from the Reed witch b a shield of ferro-ic material placed between the switch and the, the contacts will. When the shield is removed, the reed contact s become icall actuated and close. ic shield

10 10 Reed witch Application otes Permanent Magnet areas of Operation holding off off holding on on off holding on on off holding x- x+ x- x+ z- z+ z- z+ x- x+ x- x+ Magnets The materials used for Reed witch s are generall ALIO (an aluminium nickel cobalt allo), ceramic (barium ferrite or another metal oxide) or rare earth s. Due to their specific ic characteristics, the tpes of s differ in shape: ALIO s are bar s with a length/diameter ratio of 3/1 to 5/1; oxide s are generall disc or moulded s. Also important to note is the difference in temperature coefficient: ALO: 0.02 %/K, oxide: 0.2 %/K In General: The sensitivit of a reed switch is a measurement of the ic energ required to operate the switch. The unit of measurement is Ampere-Turns(AT), which is the current in a given coil multiplied the number of turns on that coil. Manufacturers of reed switches will set their machines such that the aim to produce a particular operate AT but, due to tolerances in materials, machiner and operator control, the switches produced will have a range of operate AT. The reed switches are then measured and sorted into bands of AT, and stocked in those bands. Part umber sstem witch ize = ompact D = tandard M = Miniature = ubminiature T = Tin V = Ver Tin ontact Materials R = Rhodium T = Tungsten D = Durel ontact Form A = /O = /O For each Reed witch tpe the available range of operate sensitivit is given in the data table. Other operate sensitivities are available on request. Life xpectanc: 5 6 The life expectanc of a Reed witch is about switching ccles with maximum power. With a low load the life expectanc can reach 8 5x10 operations. The mechanical life expectanc can reach at least 9 10 operations. The Life xpectanc is considerabl reduced, through the switching of Inductive, apacitive and Lamp loads, due to the maximum current being exceeded. Pull In ensitivit Tolerance: The given operate sensitivit of the Reed witch has a test equipment tolerance of ± 2 AT. Approvals: imilar switch tpes can be supplied with UL & A approvals on request. D R A G / witch Pressure 2 = on-pressurised 5 = Pressurised 8 = Vacuum Operate ensitivit band in AT Product variants ontact Variant 0 = tandard Performance 1 = ize variant 5 = High Insulation 6 = Increased Power ontact 8 = High Power ontact 9 = ize variant xample : DRA282G = tandard size - Rhodium contact - /O - on-pressurised - High Power ontact - Operate ensitivit AT.

Form A Small physical size. Centre or offset contact configurations. High speed switching. Sub-Miniature Normally Open

Form A Small physical size. Centre or offset contact configurations. High speed switching. Sub-Miniature Normally Open Reed witch ub Miniature & in witches orm A hese tin reed switches are designed for low power and high speed switching with maximum sensitivit. heir extremel small size make them ideal for Dual In Line