Magnetic actuators

Figure 9.9 Kinematics of the actuating magnetic field for three-dimensional stroke patterns.

A magnetic field due to an electric current can be turned on and off simply by turning the current on and off. A piece of iron attached to the end of a spring having the other end fixed can be moved with a magnetic field and returned to its initial position by the spring. The iron piece can then be used to actuate a switch or move a lever on a valve. Applications of this principle include electrically controlled valves in a washing machine and an electrically controlled switch for the starter in an automobile. 

Finally, the control unit, apart from controlling voltage, has a magnetic polarity reversal switch operated by a variable timer, usually set to actuate every minute that cleverly ensures no scale can build up inside the unit, making the entire system maintenance free. ... 

When the development of a scientific field expands, the need for handbooks arises, wherein the information that appeared earlier in journals and conference proceedings is systematically and selectively presented. The sensor and actuator Held is now in this position. For this reason, Elsevier Science took the initiative to develop a series of handbooks with the name "Handbook of Sensors and Actuators" which will contain the most meaningful background material that is important for the sensor and actuator field. Titles like Fundamentals of Transducers, Thick Film Sensors, Magnetic Sensors, Micromachining, Piezoelectric Crystal Sensors, Robot Sensors and Intelligent Sensors will be part of this series. 

Gonzalez C., Collins S.D., Magnetically actuated fiber-optic switch with micromachined positioning stages, Optics Lett., 1997 22(10) 709-711. 

Rife J.C., Miller M.M., Sheehan P.E., Tamanaha C.R., Tondra M., Whitman L.J., Design and performance of GMR sensors for the detection of magnetic microbeads in biosensors, Sensor Actuat A-Phys. 2003 107 209-218. 

Mistlberger G, Borisov SM, Klimant I (2009) Enhancing performance in optical sensing with magnetic nanoparticles. Sens Actuators B 139 174—180... 

Anker JN, Koo Y, Kopelman R (2007) Magnetically controlled sensor swarms. Sens Actuators B 121 83-92... 

Fuze, Mine. A fuze designed to initiate a train of fire in a land mine. For initiation of underwater (sea) mine a device known as "Firing Mechanism, Underwater Mine" It is a device contg combustible or explosive components, which can be actuated by an acoustic signal, impact, hydrostatic pressure, and/or magnetic influence (Ref 40a, pp 71... 

Influence Sea Mines, were of various shapes, but usually they were cylindrical, like a bomb in appearance. They did not require contact with a ship in order to fire, and hence could be laid on the bottom many feet below the ship. Any physical change which took place in the water around the mine to the ship s passage over it could be utilized to actuate the firing mechanism. However, the most common types were magnetic and acoustic. Any mine without horns or antenna was almost certainly either an influence mine, or else a Controlled Mine, connected by an electric cable to the shore and fired by sending a current thru that cable (p 35)... 

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