Abstract: A brushless motor system which can suppress adverse influences of electromagnetic noise without increasing the size and enhancing the performance of a filter circuit. In a brushless motor system comprising a brushless motor, an inverter, and a direct current power source, a noise return line for returning a noise current is connected between the brushless motor and the inverter. The noise current is generated in the inverter and reaches the brushless motor. With the provision of the noise return line, a common mode current leaking from the brushless motor to a ground can be reduced.

Abstract: The present invention discloses a fan protection apparatus and related method thereof. The fan protection apparatus has a control circuit and a counter. According to the fan protection method, the user can set the acceptable restart number and the special time for auto restart. The fan protection apparatus and method can force to stop the fan when the fan encounters an abnormal situation. When the stop time has passed, the fan is automatically restarted. The present invention counts the number of restarts. If the number of restarts equals the set number and the abnormal situation also cannot be eliminated, the present invention cuts off power to the fan.

Abstract: A method and apparatus for generating a poly phase signal set from a single signal output of a single phase instrument. The method comprising: generating a first signal output X representing the single signal output; processing the single signal output to generate a time delayed version Y_Raw of the single signal output by a time delay T; and processing the time delayed version Y_Raw to compensate for frequency changes in the single signal output and generating a second signal output Y of the poly phase signal set. The second signal output Y is displaced from the first signal output X by about 90 degrees.

Abstract: A hybrid control for a clothes dryer which combines an electromechanical timer and a microprocessor. The electromechanical timer has a plurality of switches connected to a plurality of input ports of the microprocessor. The timer switches are driven by a plurality of cams such that the plurality of switches open and close in response to the cams at predetermined angular positions which define control positions of the timer. In this manner, the switches provide control input to the electronic circuit for initiating the dry cycle and further provide control input to the electronic circuit during the dry cycle such that the electromechanical timer and the electronic circuit operate together to control the dryer operation. The timer is arranged such that a change from one control position to an adjacent control position results in only one switch being either opened or closed.

Abstract: A microcomputer-based electronic controller for a dishwasher utilizes a motor driven timing cam for selectively energizing the electromechanical components of the dishwasher. An internal diagnostic routine in the microcomputer insures that the timing cam is advanced when the microcomputer calls for power to be applied to the motor.

Abstract: A shut-off device for installation in the waste gas line from combustion spaces. The device includes a flow-through housing, a shut-off plate mounted in this flow-through housing and adjustable, and a positioning motor arranged on the outside of the flow-through housing for the shut-off plate. The shut-off plate is biased by a spring in a direction toward a first terminal position defined by an abutment and is capable of being adjusted by the positioning motor in a direction toward a second terminal position defined by a second abutment. At least one limit switch is provided for actuation by a control element in the open position of the shut-off plate and serving to initiate operation of combustion spaces arranged upstream from the shut-off device. The positioning motor is a rapidly rotating electric motor having a motor shaft connected with the transmission input of a step down transmission for converting the rotary speed of the motor into a slower speed.

Abstract: A control system for automatically controlling the operation of a plurality of fans for a cooling tower so that the minimum number of fans and the lowest speeds are used to provide the required cooling necessary at any one time. The fans are individually controlled in response to the temperature of the working fluid, to be either off or operated at a low or high speed so that as the temperature of the working fluid increases, more fans are turned on first to their low speed and then to their high speed. Safety features are provided for starting the system and for changing the speeds of the fans to prevent damage to the control system and unnecessary wear on the fan motors.

Abstract: A motor is electrically coupled to a power source through a motor starter. The motor is selectively operated by a relay to connect and disconnect the power source to the motor. A counter accumulates a count of motor failures and produces an inhibit signal should the frequency of occurrence of such motor failures exceed a given level. The relay is operated by an inhibit signal to cause the motor starter to disconnect the power source from the motor.

Abstract: A motor is electrically coupled to a power source through a motor starter. The motor starter is selectively operated by a relay to connect and disconnect the power source to the motor. A counter is set whenever a select motor temperature condition exceeds a predetermined level to provide an indication of the number of motor starts. The relay is operated to cause the motor starter to disconnect the power source from the motor whenever the motor fails to run continuously during a given time period following a predetermined number of starts.