The Singer Company

Bruce E Arnold

Marvin Kurland

Leonard I Horey

Gary D Jones

A microcomputer-based motor control system provides overload protection by incrementing a register whenever a full power condition exists and decrementing the register when less than a full power condition exists. When the register reaches a predetermined value, this indicates an overload condition.

Overload protection in a motor control system

An electronically controlled household sewing machine includes an arrangement for needle positioning. The machine responds to a tap of the foot controller for stopping the sewing machine at the next change of state of the armshaft timing signal.

Needle positioning arrangement in an electronically controlled household

A motor control system utilizes a low cost switched controller for provding operator initiated control signals. The controller has therein a pair of switches which together define four possible modes of operation, depending upon operator manipulation of the controller. These four modes cause the system to either stop the motor, decrease the speed of the motor, maintain the speed of the motor constant, or increase the speed of the motor.

Motor control system utilizing switched controller

A velocity servo for a motor wherein a high speed tachometer is replaced by an arrangement which mathematically converts the input voltage and current to the motor into a speed signal, utilizing known formulas and constants. To maintain accuracy of the servo when the constants change value with the temperature, an inexpensive low speed tachometer is utilized to derive a signal indicative of the actual speed of the motor and this speed signal is compared with the mathematically computed speed signal. In the event that there is a difference, the constants are modified in accordance with such difference. This can be implemented either by electrically alterable circuit values or through computer or microprocessor techniques.

Velocity servo with adaptive tachometer feedback

A high speed electronically controlled industrial sewing machine having an automatic back-tack capability is disclosed. To achieve balanced stitching in the first and last tacks of a seam while still operating at high speed, the stitches in the tacks are counted and additionally a fixed time delay is provided in the feed reversal command circuitry to compensate for system inertias which result in response time delays of the sewing machine to the feed reversal command signals.

Automatic back-tack system for industrial sewing machine

A control system is disclosed for providing a dual voltage electrical power supply for a variable load such as an electro-mechanical clutch-brake power transmitter of the type used for instance for a loom transmitter. A control arrangement is disclosed in which high voltage is continuously available under control of low voltage timing and drive circuits.

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Clinton, NJ, United States of America

Bruce E Arnold