Abstract: A simple and inexpensive device to record one or more phenomena, employing the transmission and receiving of light as a method of sensing pen position. A pen holder (13) is mounted on a pen block (12), as is a light receiver element (15), and pen block (12) is mounted on a threaded pen rod (11), rod (11) being rotated to move the pen block (12) along the length of the pen rod (11). As pen block (12) moves, light receiver element (15) intercepts more or less light flux from a fixed light source (16), producing a voltage in receiver (15) which is processed to a suitable level by an op amp (40), this voltage being called the Lov. Simultaneously, a voltage directly related to the phenomenon being recorded, as generated by a sensor (44), is processed by an op amp (41) to a desired voltage level called the Pov: the Lov and Pov are now compared in a comparator circuit (42) whose output is buffered by an op amp (43), the output of which is called the Mcv.

Abstract: The present invention is embodied as an arrangement for positioning a pen in a device that records the time profile of a measurement signal which can be connected to the device. The arrangement provides high mapping accuracy of the measurement signal onto the recording signal at a low cost and with DC isolation between the measurement signal and drive means of the pen. The arrangement uses a control loop that has a pulse width modulator whose output is DC-decoupled to a signal converter that provides the drive signal for the motor that moves the pen.

Abstract: Chart recording apparatus for use with industrial instrumentation systems and the like, and comprising memory means to maintain a signal level for long time periods without drift. An input signal level is translated into the positioning of a pen, through the use of an actuator motor controlled by the input signal and a position feedback signal. A friction device is coupled to the pen to hold it in any given position, thereby to serve as a memory for the input signal level. The friction device comprises a thin vane-like element which is secured to the movable member and disposed in the air-gap of a permanent magnet. The air-gap also includes a mass of tiny magnetizable particles which, under the influence of the magnetic field, engage the surfaces of the vane-like element to develop a frictional restraining force.

Abstract: Signal-processing apparatus for use with industrial instrumentation systems and the like, and comprising a memory to maintain a signal level for long time periods without drift. An input signal level is translated into the positioning of a movable member, through the use of an actuator motor controlled by the input signal and a position feedback signal. A friction device is coupled to the movable member to hold it in any given position, thereby to serve as a memory for the input signal level. The friction device comprises a thin vane-like element which is secured to the movable member and disposed in the air-gap of a permanent magnet. The air-gap also includes a mass of tiny magnetizable particles which, under the influence of the magnetic field, engage the surfaces of the vane-like element to develop a frictional restraining force.

Abstract: Apparatus is provided for digitizing a pattern by utilizing the computer controller and motor driver of an x-y table used in an automatic sewing machine. A manually operated control stick is installed on the machine and connected through the controller to send command signals to the motor drivers. A viewer is mounted on the machine to project a pattern, which is placed on the work surface of the x-y table, onto a small screen. The operator may then, through the use of the viewer and the control stick, move the x-y table through the desired pattern. Such movement is recorded in the computer for use in generating a control tape for the specific pattern.

Abstract: Signal-processing apparatus for use with industrial instrumentation systems and the like, and comprising memory means to maintain a signal level for long time periods without drift. An input signal level is translated into the positioning of a movable member, through the use of an actuator motor controlled by the input signal and a position feedback signal. A friction device is coupled to the movable member to hold it in any given position, thereby to serve as a memory for the input signal level. The friction device comprises a thin vane-like element which is secured to the movable member and disposed in the air-gap of a permanent magnet. The air-gap also includes a mass of tiny magnetizable particles which, under the influence of the magnetic field, engage the surfaces of the vane-like element to develop a frictional restraining force.

Abstract: An apparatus capable of digitizing or plotting coordinate locations and lines utilizes an automatically controlled carriage that is translated over the supporting surface of a digitizing and plotting table and a free cursor for identifying specific coordinate locations on the table. Radiation means, such as electromagnetic coils, are mounted on the carriage and the cursor to produce signals indicative of the relative positioning of the carriage and cursor during a digitizing mode of operation. The position signals are transmitted to controlled drive motors which cause the carriage to follow the cursor over the supporting surface. Encoders, also operated by the drive motors, allow the position of the carriage and, hence, the cursor to be recorded for subsequent usage. A plotting instrument such as a pen is mounted on the carriage so that the apparatus can be used in a plotting mode of operation to generate graphic information.