Protective drive-level limited for an electro-hydraulic vibrator

Patent · Tue May 07 04:00:00 EDT 1985

OSTI ID:6390512

Goodloe, K J; Landrum, Jr, R A

In accordance with an embodiment of this invention, voltages are received from the pilot valve torque motor, the main servo valve and the actuator indicating the value of the torque motor current, spool position and actuator displacement. The received voltages are compared to a preselected threshold value. When one or more of the voltages exceed a threshold value, an attenuator control voltage is generated. An attenuator circuit is coupled between the reference driver signal generator and the DC servo amplifier. The attenuator control voltage, if present, is applied to the attenuator circuit and scales down the reference driver signal as a function of the error signal level thereby to limit the torque motor current and consequently the displacements of the main servo valve spool and actuator shaft.

• Assignee: Western Geophysical Company of America
• Patent Number(s): US 4516230
• OSTI ID: 6390512
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580203* -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
ACTUATORS
CONTROL EQUIPMENT
ELECTRIC MOTORS
ELECTRIC POTENTIAL
EQUIPMENT
EXPLORATION
FLUID MECHANICS
GEOPHYSICAL SURVEYS
HYDRAULICS
LIMITERS
MECHANICS
MOTORS
SEISMIC SOURCES
SEISMIC SURVEYS
SERVOMECHANISMS
SURVEYS
TORQUE