MagnetismMagnets & Magnetic FieldsMagnetic flux linesPowerPoint PresentationOpposites Attract / Likes repelArrangement of atomsArrangement of atomsPermeabilityReluctanceElectromagnetismElectromagnetsConventional TheoryElectron TheorySaturationSlide 15Electromagnet questions?RelaysSlide 18Relay in operationNormally Open and Normally ClosedNormally Open RelayISO Mini RelaySlide 23Slide 24ISO Micro RelayChecking RelaysTypical horn circuitRelay Questions?Parallel circuit reviewParallel Circuit RulesSlide 31Parallel circuit questions?Don’t panic!YOU CAN DO IT!MagnetismMagnetismAuto 2 after series circuitsMagnets & Magnetic FieldsMagnets & Magnetic FieldsMagnetic flux linesMagnetic flux linesFlux Always flows from North to SouthOpposites Attract / Likes repelOpposites Attract / Likes repelArrangement of atoms Arrangement of atoms In metal that In metal that has has notnot been been magnetizedmagnetizedArrangement of atomsArrangement of atomsIn metal that In metal that hashas been been magnetizedmagnetizedPermeabilityPermeabilityAbility of materials to become Ability of materials to become magnetizedmagnetizedReluctanceReluctanceResistance to magnetic lines of fluxResistance to magnetic lines of fluxHigh reluctance = AirHigh reluctance = AirLow reluctance = Soft IronLow reluctance = Soft IronElectromagnetismElectromagnetismAny time current flows thru a conductor,A magnetic field is created around the conductorElectromagnetsElectromagnetsCan increase the strength by;Can increase the strength by;–Adding more windingsAdding more windings–Increasing the currentIncreasing the current»More voltageMore voltage»less resistanceless resistance–Wrap windings around Wrap windings around something with low reluctancesomething with low reluctanceConventional TheoryConventional TheoryLeft hand thumb rule applies:With left thumb pointing the way currentFlows, your fingers show you whichWay the magnetic field is built around.Says:Current flowsFrom Positive “+” to Negative “-”Electron TheoryElectron TheoryRight hand thumb rule applies:With right thumb pointing the way currentFlows, your fingers show you whichWay the magnetic field is built around.Says:Current flowsFrom Negative “-”To Positive “+”SaturationSaturationIs the point where the magnetic Is the point where the magnetic strength eventually levels offstrength eventually levels offMore windings, the longer it takes More windings, the longer it takes but the stronger the fieldbut the stronger the fieldSaturationSaturationTurn on pointSaturation pointTurn on pointSaturation pointTwo coil ramps Taken with a Lab Scope and An amp probe.Shorted coilAbout 4.25 mSElectromagnet questions?Electromagnet questions?RelaysRelaysRelaysRelaysUse a small amount of current Use a small amount of current to control (switch) a large to control (switch) a large amount of currentamount of current–Control circuit has a winding to Control circuit has a winding to create a magnetic field (#1 & #3)create a magnetic field (#1 & #3)»Low amp circuitLow amp circuit»Also called the primaryAlso called the primary–Controlled circuit has a switch to Controlled circuit has a switch to control current flow to a higher control current flow to a higher amp load (#2 & #4)amp load (#2 & #4)»Also called the secondaryAlso called the secondary»High amp circuitHigh amp circuitRelay in operationRelay in operation1 & 3 the control circuit2 & 4 the controlled circuitSend currentThru 1 & 3 toCreate fieldVoltage present at #4Trying to push currentOut #2 to high current loadHigh currentSwitched to Load out #2Normally Open and Normally ClosedNormally Open and Normally ClosedNormally Open (N O) RelayTakes energy to switch closedNo energy, switch is openNormally Closed (N C) RelayTakes energy to switch openNo energy, switch is closedNormally Open RelayNormally Open RelayISO Mini RelayISO Mini RelayMost manufactures went to this standardTerminals #30 to #87a are NC and terminals #30 to #87 NONCNOISO Mini RelayISO Mini RelayTerminal #30 comes from B+Terminal #87 goes to loadTerminal #87a is rarely used (wiper park circuit)Terminals #85 & #86 are the controlCircuit (winding) usually 70 ohmsISO Mini RelayISO Mini RelayISO Micro RelayISO Micro RelayChecking RelaysChecking RelaysFind control and controlledCircuits with ohmmeterPower up control circuitWhile checking controlledTypical horn circuitTypical horn circuitIn steering wheelRelay Questions?Relay Questions?Parallel circuit reviewParallel circuit reviewParallel Circuit RulesParallel Circuit RulesMore than one pathMore than one path–Has a splice in the circuitHas a splice in the circuitVolta geVolta ge stays the same stays the sameTotal Total Ampe r ageAmpe r age is divided between the is divided between the pathspathsTotal Total Resistan ceResistan ce is always lower that the is always lower that the smallest path or branchsmallest path or branchOHMS LAW STILL WORKS THE SAMEIf volts and ohmsAre equal, thenOne amp will flow.Parallel circuit questions?Parallel circuit questions?Lets apply what weHave learned.Don’t panic!Don’t panic!Apply what you have learned about relays and Apply what you have learned about relays and parallel circuitsparallel circuitsDraw up a typical horn circuitDraw up a typical horn circuit–Remember the horn switch is in the steering wheelRemember the horn switch is in the steering wheel–We don’t want to send the high current through the We don’t want to send the high current through the horn switch, so we will use a relayhorn switch, so we will use a relay–The horn is the load that will use high ampsThe horn is the load that will use high ampsMake sure there is a complete path in the Make sure there is a complete path in the contro lcontro l circuit and the circuit and the contro lle dcontro lle d circuit circuitYOU CAN DO IT!YOU CAN DO IT!Apply what you have learned about relays and Apply what you have learned about relays and parallel circuitsparallel circuitsDraw up a typical horn circuitDraw up a typical horn circuit–Remember the horn switch is in the steering wheelRemember the horn switch is in the steering wheel–We don’t want to send the high current through the We don’t want to send the high current through the horn switch, so we will use a relayhorn switch, so we will use a relay–The horn is the load that will use high ampsThe horn is the load that will use high ampsMake sure there is a complete path in the Make sure
or
We will never post anything without your permission.
Don't have an account? Sign up