Because of permanent improvement of our products, drawings, descriptions, features used on these data sheets are for guidance only and can be modified without prior advice field. Theseglassbulbs are sealed andfilledwith argon orunder vacuum, therefore they are a magnetic protected from of oxidation presence the in close to particularity the has 70VA, which to 10 of capacity breaking a with contact strip reed flexible a with bulbs small areswitches Reed Reed sible to designcompact devices. current electronicin low voltage low This and usedcharacteristicsdetection pos they circuits. for switches because this are level makes usecatalog reed in switches flow Most flap pistonor paddle, the on detector depends the power on available the and rating, electrical its forcecontactwith increasesgeneral,operateelectricalrequiredthe to In an 20VA to 10 of rating power a with contacts reed with systems(0.5Amp), to 50gramsfor for grams snapactionmicro-switches witha5Amp250V of rating tenths few a from range can It device. contact electrical the actuate to required is force certain A The electrical contact system: reed ormicro-switch. The snapactionmicroswitch is particularlysuitable for devices operating at240or400Vand when high electrical rating is required and does notallow suchagreat control thanreed switches. there is no radio interference, and the contact does not deteriorate. Mechanically, this type of contact, also called “energy Therefore sec. storing 1/1000 than less in contact” distance is contact the the The arcing second. spacing reaches to extinguish per much around 1m is moreswitches, action speed contact opening snap On complicated, expensive, Snap action switches stick .The purposeofprotection circuits is to prevent byshortingthisarcing, voltage through an alternate path or together weld burn, contacts to the cause can Arcing arcing. called is phenomenon This path. conductive a making them, betweengap the in medium the down break can it large enough, voltage is the switch contacts. If the across appears frequency voltage, which generates large high load a the of inertia electrical or inductanceinterrupted, the is current When life. dependable long, insure to order in protection require contacts switch transformers, reed and solenoids relays, as such loads inductive switching When expected. Inthe10Volt range, highercontact wear willtake place. Switching 10Volts life @10mA, times of50million to 200millionoperations can be expected. Switchingwhereloads or load no voltagethe Volts5 than less is contactsless,the or mA 10 @ undergo no or little life and wear in times operations of billions of excess are contact closes.Therefore, piston movement islimited to achieve requested operation The peaktransient voltage that occurs whenthe switch opens isdecreased to avalue generated voltage whenthe switch opens.Aresistor can beaddedinseries with When located inside the piston arrives at the center ofthereed switch, the A 1N4004 diodeisconnected cathode-to-positive .The diodedoes not conduct Micro-switches have large differential travels, providing large flow differentials The Zener diode shouldbe sized for avoltage somewhat higherthanthecircuit when the loadisenergized, butconducts andshortsoutthe peak transient Microswitches have ahigheroperating force, sothey need larger paddles DC loadprotection contact withBack to Back Zener diode Microswitches are more expensive thanreed switches equal to the backto back Zener diode voltage. DC loadcontact protection circuit withdiode Programmable logiccontroller (PLC’s) circuits between contact openingandclose Solid state (SSR) triggercircuits Flow switcheshistoricalandtechnicalforeword Computer circuits source voltage Disadvantages Piston types Small relays the diode. the diode. Suitable mode. Magnet displacement andreed switch operation inflow switches Description ofthedifferent parts Microswitches vs reed switches inflowswitches Reed switch applications inflow switches E-Mail: [email protected] www.ultimheat.comWeb: Reed switches The capacitor hashighimpedance at 50/60hertz, andisessentially ashortcircuit to The varistor resistance decreases sharplywhenvoltage reaches itstriggervalue, and A magnet islocated insidethepaddleorflap.Whenitarrives near shorts outthepeak transient generated voltage when the switch opens.Varistor should be sized for avoltage somewhat higherthanthecircuit source voltage Power contactor coil circuits (Unlessprotected by anarc suppression circuit) Microswitches are easily made withSPNC, SPNO orchange over contacts A resistor (R)andcapacitor (C)are connected inparallel withthe switch. Microswitches have higher electrical ratings, in110VAC and230VAC Solenoid valves (Unless protected by anarc suppression circuit) Resistor value (E=power supplyvoltage): R=E/(10.I Snap action contact switches generate low EMC very AC loadcontact protection circuit withR/Ccircuit Small electrical motors smallDCmotors ,including AC loadprotection contact with Varistor high frequencies ofgenerated voltages. the reed switch, thecontact closes. Capacitor value: C=I²/10 Paddle andflaptypes Incandescent lamps Not suitable Advantages (I+50 /E) ) -

7 Unless exceptionally specified by this logo , products and components in this catalogue are made by Ultimheat alliance members.