Magnesense Patents

Sensorless Position Measurement

System for Control of an Electromagnetic Actuator  U.S. 6,249,418  Gary Bergstrom

We control pulse duty cycle, sense current, and derive the position and velocity of the actuator, as needed for sensorless servo feedback and soft landing control.

State Space Controller

State space control of solenoids  U.S. 7,099,136   Joseph Seale, Gary Bergstrom

From multiple simulation runs or multiple instrumented landings we derive a “roadmap,” in the solenoid state space, of routes that lead to good landings.  Use of this “roadmap” yields consistent good results with straightforward software.

Single-Winding Solenoid  

Single-Winding Dual-Latching Valve Actuation Solenoid U.S. 6,724,606  Joseph Seale, Gary Bergstrom

The two windings of a traditional system are wired in series and driven from one channel of driver electronics.  The surprise: operation from one driver is almost as efficient as from two, and significantly cheaper.

Three wire Controller
Three Wire Drive/Sense for Dual Solenoid, U.S. 7,612,978 Gary Bergstrom, Joseph Seale
The two windings of a traditional system are wired in series and a center tap brought out from the common connection, so the windings are driven with three power drivers instead of four.

Flat Lam  

Flat Lamination Solenoid  U.S. 6,550,745  Gary Bergstrom

Stack the armature laminations in a horizontal plane rather than in a vertical plane.  The eddy current losses are only slightly worse, and the structure is mechanically much stronger.

Side-by-Side Helical Spring  

Spring for Valve Control in Engines   U.S. 6,341,767  Joseph Seale, Gary Bergstrom

A single piece of spring wire is bent into a double side-by-side helix with fixed ends and a moving center attachment.  It’s a good shape to fit the available space of a valve actuator, it’s less expensive, and the moving mass is lower.

Quick Landing Solenoid  

A Solenoid for Efficient Pull-In and Quick Landing, U.S. 6,737,946  Joseph Seale, Gary Bergstrom

Passive magnetic design gives a quick transition from armature deceleration to latching and holding, reducing total transit time.  Passive damping windings complement active servo control to yield landings that combine quickness with low impact.

Sensorless Position without Drift 

System to Determine Solenoid Position and Flux without Drift  U.S. 6,300,733  Gary Bergstrom

Our “Sensorless Position Measurement” is modified to overcome long-term drift of the flux linkage integral, using current ripple data associated with the frequency of the PWM drive voltage.


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