Abstract: A thermally efficient motor housing assembly including a plurality of transistors and a printed wire board (pwb) for controlling a stepper motor and also including a plunger array and a spring array along with a combined heat sink and pwb enclosure.

Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for preventing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to prevent the excitation of system harmonics and prevent step motor operational instability.

Abstract: An electric stepper motor having increased motor torque includes a thru-hole, a rotor and a stator. The thru-hole allows use with a chamber and provides transport of hardware and elements into the chamber. A first and second pair of rotor cups separated by a non-magnetic spacer disc provide increased motor torque.

Abstract: The current in each phase of a multi-phase step motor is monitored and the excess phase current above the set point current, as required on a cycle-by-cycle PWM basis, is reduced thereby bringing each phase current down to the set point. The PWM frequency is automatically adjusted to maintain a minimum number of PWM edges within a portion of the current waveform. A maximum charge/discharge time is specified as a percentage of the PWM period. These provide an accurate independent current control within each phase of a multiphase step motor.

Abstract: The sense signal, which is used to indicate that the motor phase current in a stepper motor is at the set point, is marked both before and after each pulse width modulator edge thereby reducing susceptibility to commutation noise from any phase. A mask time is created for a period before and after a PWM edge. The phase current is balanced during this mask time by removing and replacing the phase current.

Abstract: A waste diversion system for diverting the effluent from a manufacturing process, such as polishing the surfaces of silicon wafers, has an electrically controlled diverter valve for receiving the effluent and diverting it either to a “dirty” output for waste treatment, or to a “clean” output for recycling or other treatment. To determine whether the effluent is “dirty” or “clean”, parameter sensors are located to sense particular parameters such as turbidity, conductivity, ORP, pH, or ion content, as desired. One sensor is located to sense the parameters of effluent flowing into the diverter valve; and the other sensor is located to sense the parameters (typically, the same parameters) of the flow from the “dirty” or waste side of the diverter valve. Only when both of the sensors indicate that the effluent is “clean” is a signal provided to the diverter valve to switch it to the clean output.

Abstract: An electric stepper motor includes a thru-hole, a rotor and a stator. The rotor consists of a pair of hollow magnetic metal flange-shaped laminations arranged within a hollow magnetic sleeve. The motor can be field-converted from rotary to lineal translation by attachment of a threaded nut to the motor shaft mounting face. The thru-hole allows use with a chamber and provides transport of hardware and elements into the chamber.

Abstract: A sanitary protective cover or sheath for the ear canal probe of a tympanic thermometer. The speculum has a generally tubular body portion and an infrared transparent membrane attached to and sealing the forward end of the body portion. While the tubular body portion is being injection molded of plastic material such as polypropylene or polyethylene, a film of a similar plastic material is mated to the forward end of membrane and is thus severed from the film and one side thereof thermally bonded to the tubular body portion. At the same time a bonding ring of roughly the same diameter as the forward end of the tubular body portion is injection molded. The ring is thermally bonded to the opposite side of the film in alignment with the forward end of the tubular body portion.

Abstract: A body temperature thermometer has a probe head assembly (8) which includes a first sensor (10), such as a thermopile, for generating a first output signal representative of an amount of infrared radiation impinging thereon The probe head assembly further includes a waveguide (16) and a surrounding hollow probe (14) for receiving infrared radiation emitted by a biological surface tissue, such as the external ear canal and tympanic membrane of a patient, and directing the radiation to the first sensor. A second sensor (12) is mounted in the probe head assembly for generating a second output signal representative of a temperature of the first sensor. A third sensor (26) is thermally coupled to the waveguide for providing a third output signal representative to the temperature thereof.

Abstract: A shaft coupling having cooperatively spaced split collars mounted in juxtaposition and releasably locked to each other and to shaft ends for non-axial displacement of a shaft end.