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Linear Devices Corporation (Lectrotab brand) was founded in 1997 to develop a line
of electromechanical trim tab actuators that would overcome the numerous problems
inherent to hydraulic-based systems. Many design features that resolved these problems
are patented and exclusive to the Lectrotab product line.
| Issue |
Hydraulic-Based Systems |
Lectrotab (Electromechanical System) |
| Cylinder O-ring Damage |
Barnacle growth on ram cylinder damages sealing o-ring, causing oil leakage |
Lectrotab actuators utilize a patented upper o-ring placement beyond the reach of barnacle growth, eliminating water seepage (U.S. Patent #5,881,666) |
| Oil Leakage (Hoses and Fittings) |
Oil leaks from damaged hoses and corroded hydraulic fittings requiring constant refilling of oil reservoir |
Electric actuators are potted, sealed, waterproof, and contain no hydraulic oil |
| Pushing Force |
Hydraulic systems may use two or more cylinders to compensate for excessive water force during tab deployment |
All Lectrotab actuators are tested to push a load force of 1000 lbs or more; so in many cases, one Lectrotab actuator can replace two hydraulic cylinders |
| Cylinder/Tab Damage while backing down |
Spring in cylinder may be too weak to hold tab in place when backing down on boat, causing cylinder and tab to break |
Internal friction brake prevents unwanted deployment when backing a boat down |
| Unwanted Tab Retraction while underway |
Oil leakage causes tab to slowly retract while underway |
Internal friction brake prevents unwanted retraction while underway; the stronger the water force on tab, the greater the braking effect |
| Failure of Feedback Sensor |
Many hydraulic-based systems use feedback sensors to indicate tab position; sensors are subject to corrosion, leading to loss of adjustment or failure |
Lectrotab systems utilize precision made gears, a ballscrew, and electronic braking circuit, which eliminates the dependency on a feedback sensor Tab position indicators are based on deployment and retraction time |
