Fun with Magnets Class 5 PPT

 Page 1


Fun with Magnets. 
An Adventure into Magnet Field 
Prediction and Mapping 
 
Bryan LaBarge 
Page 2


Fun with Magnets. 
An Adventure into Magnet Field 
Prediction and Mapping 
 
Bryan LaBarge 
Background 
• Applications of magnetism range from 
hard drives to security systems to sensor 
technology 
• Magnets typically used to open (or close) 
electronic circuits 
• Switches in these types of circuits are 
reed-based 
Page 3


Fun with Magnets. 
An Adventure into Magnet Field 
Prediction and Mapping 
 
Bryan LaBarge 
Background 
• Applications of magnetism range from 
hard drives to security systems to sensor 
technology 
• Magnets typically used to open (or close) 
electronic circuits 
• Switches in these types of circuits are 
reed-based 
Reed-Based?  
• 1930’s – Bell Labs create the reed switch 
 
• Glass tube, filled with inert gas, contains 
two magnetic reeds 
 
• Reeds extend out of sealed glass tube 
 
• Magnetic field forces the two reeds closed 
Page 4


Fun with Magnets. 
An Adventure into Magnet Field 
Prediction and Mapping 
 
Bryan LaBarge 
Background 
• Applications of magnetism range from 
hard drives to security systems to sensor 
technology 
• Magnets typically used to open (or close) 
electronic circuits 
• Switches in these types of circuits are 
reed-based 
Reed-Based?  
• 1930’s – Bell Labs create the reed switch 
 
• Glass tube, filled with inert gas, contains 
two magnetic reeds 
 
• Reeds extend out of sealed glass tube 
 
• Magnetic field forces the two reeds closed 
How can I use a reed switch? 
• Can be used in any electronic circuit 
where a switch is needed. 
 
• Perfect for position sensing 
– Used with a magnet as a system, magnet OR 
switch can be moved 
– Strength of magnetic field “pulls in” the switch 
Page 5


Fun with Magnets. 
An Adventure into Magnet Field 
Prediction and Mapping 
 
Bryan LaBarge 
Background 
• Applications of magnetism range from 
hard drives to security systems to sensor 
technology 
• Magnets typically used to open (or close) 
electronic circuits 
• Switches in these types of circuits are 
reed-based 
Reed-Based?  
• 1930’s – Bell Labs create the reed switch 
 
• Glass tube, filled with inert gas, contains 
two magnetic reeds 
 
• Reeds extend out of sealed glass tube 
 
• Magnetic field forces the two reeds closed 
How can I use a reed switch? 
• Can be used in any electronic circuit 
where a switch is needed. 
 
• Perfect for position sensing 
– Used with a magnet as a system, magnet OR 
switch can be moved 
– Strength of magnetic field “pulls in” the switch 
Position Sensors 
• Typically used for location doors, windows, 
moving machinery, etc., etc 
• Also used to monitor liquid level and flow 
– Switch remains stationary 
– Magnet(s) are placed in a float that moves 
with the fluid 
– Sensors tell other electronics to do something 
(open a valve, sound an alarm)