Patents by Inventor David M. Erdman

David M. Erdman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4513230
    Abstract: A laundering apparatus includes a laundry machine having a spin tub and an agitator, and an electronically commutated motor is drivingly associated with the tub and agitator through a transmission. A system controls the energization of the electronically commutated motor to effect the laundering operations of the tub and the agitator in the laundry machine.A method of operating a laundry machine, a control system for an electronically commutated motor, and a method of operating an electronically commutated motor are also disclosed.
    Type: Grant
    Filed: July 21, 1982
    Date of Patent: April 23, 1985
    Assignee: General Electric Company
    Inventor: David M. Erdman
  • Patent number: 4459519
    Abstract: Electronically commutated motor and control arrangements particularly adapted for use with refrigeration systems and methods of operating refrigeration systems are disclosed. In one form, a fan control means is provided for responding to temperature of a compartment being cooled by a refrigeration system; comparing the compartment temperature with a desired temperature; and varying the speed of an evaporator fan, thereby varying the movement of refrigerated air across an evaporator and into the compartment. A regulating circuit is provided for maintaining the evaporator at a reference temperature by controlling the output signal of an alternator which supplies energization power to winding stages of a brushless DC motor. By varying the energization level of the winding stages, a compressor, which is coupled to the motor, is caused to vary the flow rate of refrigerant through the evaporator so as to maintain the evaporator at the reference temperature.
    Type: Grant
    Filed: September 25, 1980
    Date of Patent: July 10, 1984
    Assignee: General Electric Company
    Inventor: David M. Erdman
  • Patent number: 4449079
    Abstract: A circuit for controlling the energization of an electrical load from an AC source. The circuit has a pair of DC lines, and means is provided for rectifying the AC output of the source to apply a DC voltage across the DC lines in the form of a full wave rectified sinusoidal signal. Signal switching means for connection between the DC lines and the load establishes a conductive path therebetween during a variable time interval when the voltage applied by the full wave rectified sinusoidal signal exceeds the voltage across the load, and means including the switching means is provided for chopping the full wave rectified sinusoidal signal to apply pulses to the load during the variable time interval at a frequency which is high with respect to the frequency of the signal.
    Type: Grant
    Filed: August 27, 1982
    Date of Patent: May 15, 1984
    Assignee: General Electric Company
    Inventor: David M. Erdman
  • Patent number: 4390826
    Abstract: A method of operating a laundry machine. The machine has a pair of rotatable components and is driven by an electronically commutated motor having a stationary assembly with a plurality of winding stages and also having a rotatable assembly adapted to be selectively coupled to at least one of the rotatable components. In this method, a DC voltage for application to the motor is received, and a first control function is imposed on the operation of the machine to control the application of the DC voltage in accordance with a selected one of a plurality of first waveshapes so as to provide a resultant effective voltage to the motor.
    Type: Grant
    Filed: April 17, 1980
    Date of Patent: June 28, 1983
    Assignee: General Electric Company
    Inventors: David M. Erdman, Harold B. Harms
  • Patent number: 4015182
    Abstract: A refrigeration system is disclosed as comprising a compressor driven by an electronically commutated D.C. motor for circulating a suitable coolant through a condenser and then an evaporator disposed within a chamber or compartment to be cooled. The system is particularly adapted for use as an air conditioning system for automobiles and recreational vehicles, as portable refrigerating apparatus in recreational vehicles, and refrigerating apparatus for trucks or other transport vehicles. In such applications, a power source such as a battery, alternator, or generator (or rectified alternating current) serves to energize the motor. The motor may be operated by an electronic commutating circuit responsive to the position of the rotor of the D.C. motor for efficiently commutating the energizing signals applied to the stator windings of the brushless D.C. motor. The level of energization is set in accordance with the desired temperature to be maintained by the refrigeration system, whereby the D.C.
    Type: Grant
    Filed: June 24, 1974
    Date of Patent: March 29, 1977
    Assignee: General Electric Company
    Inventor: David M. Erdman
  • Patent number: 4005347
    Abstract: A brushless DC motor is constructed with photosensitive devices for detecting rotor shaft position. Arcuate permanent magnets on the rotor provide a DC flux field while distributed stator windings, each spanning a fixed number of slots in the armature assembly, provide mutually perpendicular magnetic fields. A logic circuit comprising NOR gates and transistor switches and drivers activated in response to signals from the shaft position sensors are utilized to control current switching in the stator windings of the motor. A light interrupting shutter mounted to the rotor cooperates with the light sensitive devices which are mounted to a supporting bracket fixed to the stator assembly in a manner to selectively preset advancement of commutation of the stator windings.
    Type: Grant
    Filed: June 24, 1974
    Date of Patent: January 25, 1977
    Assignee: General Electric Company
    Inventor: David M. Erdman