Abstract: A photoelectric smoke detector includes a photoelectric chamber having a housing fabricated from an electrically conductive material.

Abstract: A pressure switch having a pressure responsive diaphragm with a backing plate for operating a snap-acting switch. The switch has a cantilevered contact blade spring with an adjustment screw providing a reaction support at the free end. The middle portion of the contact blade spring provides a preload bias against the diaphragm backing plate. The blade spring includes a moveable electrical contact on a tang formed in the middle region and includes an over-center spring for effecting a snap action of the moveable contact against stationary contacts. The actuation-deactuation differential is determined, independently of the pressure setting for switch actuation, by setting the position of the stationary contacts.

Abstract: A water temperature control circuit for a washing machine includes window detector and dual water valve drivers to modulate the hot and cold water valves to maintain the water temperature at a desired level. A temperature selector switch provides hot, regulated hot, warm, regulated warm, and cold temperature settings for the washing machine. During regulated temperature operation the window detector modulates one of the water valves to maintain the water temperature within a narrow temperature band. The window comparator includes two comparators that receive a common temperature input from a temperature sensing element. As such, no shunt resistor is required for one or the other comparators, thus improving accuracy. The control circuit operates open loop with respect to the hot and cold water valves that it controls, utilizing instead only the temperature input for controlling the proper water valve when enabled.

Abstract: A pressure regulating device for high pressure fuel systems includes a pressure sensing element attached directly to a pressure chamber. The pressure sensing element includes a semiconductor element that deflects in response to a deflection of a portion of the pressure caused by fuel pressure within the pressure chamber. A coil is electrically connected with the pressure sensing element and is configured to generate a magnetic field that moves a magnetic armature to control fuel pressure.

Abstract: A method and apparatus for mounting a controller (30) along with its program selector switch (36) and other electrical components (34) on appliance front panels is disclosed. A twist mount (40) removably mounts a selector switch (36) and printed circuit board (32) to a control panel (20) of an appliance. The switch (36) may be positioned off-center on the printed circuit board (32) in a manner creating a gravity-based rotational torque force on the twist mount (40), such that the printed circuit board (32) acts as a cantilever arm during mounting, and the selector switch (36) is held in the mounted position via the gravity force after mounting.

Abstract: A driver circuit for a latching type valve is provided which utilizes an electronic switch assembly to provide the dual polarity necessary to actuate the latching type valve to both its open and closed states. The driver circuitry includes a microprocessor and a slope detector circuit for monitoring the coil current used to energize the valve solenoid to determine when the valve armature has moved to its fully actuated position. The driver circuit preferably utilizes power MOSFET devices in the switch assembly configured into an H-bridge to drive the solenoid coil. Advantageously, the user of power MOSFET devices eliminates the necessity for a current sense resistor in the control circuitry, thereby decreasing power dissipation and increasing efficiency of the drive circuit, thereby prolonging the battery life used to drive the valve.

Abstract: An actuator is provided for controlling temperatures in a multiple compartment device wherein the actuator includes a housing and a linear oscillator disposed within the housing. The linear oscillator is coupled with an integral push rod, wherein the linear oscillator is adapted to reciprocably move the push rod along its longitudinal axis. In addition, the actuator includes a holder including a rigid member and a pin aperture. The sliding member has a knob on one end and first clip connector at an other end, the sliding member having a range of motion limited by the rigid member. The push rod has a second clip connector coupled to the first clip connector. A lever arm has a first end and a second end, the first end including a protruding member and the second end including a lever arm aperture and a lever arm pin. The knob is pivotably engaged with the lever arm aperture and the lever arm pin is pivotably engaged with the pin aperture. The protruding member is adapted to pivotably couple with the damper.

Abstract: An electromechanical relay drive system which prolongs relay life by ensuring operation of the relay in a manner to make and break contact between the contact electrodes at a zero crossing point of the switched waveform. Relay aging and environmental variations are dynamically compensated upon each actuation of the electromechanical relay to ensure proper timing of the energization and de-energization of the relay to ensure switching at the zero crossing point. Additionally, the drive system described compensates for variations in the actual contact operation during actuation for the positive and negative half cycle of the switched waveform. Furthermore, the system of the instant invention alternately energizes and de-energizes the electromechanical relay during the positive and negative half cycles of the switched waveform to prevent metal deposition from one contact electrode to the other.

Abstract: An electronic variable orifice tube suitable for use as an expansion valve in a refrigeration system providing two flow rates in response to electronic control signals comprises a bodytube, a restrictor mounted within the bodytube and defining a first flowpath. A plunger is translatably positioned within the bodytube in proximity to the restrictor and defines a second and a third flowpath. A valve actuator is functionally coupled to the plunger to translate the plunger within the bodytube to transition between the two flow rates. A high flowpath is formed through the bodytube by the first, second, and third flowpaths, and a low flowpath is formed through the bodytube by the first and the second flowpaths to the exclusion of the third flowpath. A solenoid may be used as the valve actuator and a spring may be employed to return the plunger to its quiescent state when the solenoid is not energized.

Abstract: A motor start circuit for A-C electric motors. A microprocessor-based circuit is used to detect the phase shift that occurs in the motor current as the motor goes from the initial locked-rotor state to the running state. This circuit applies current to a motor `start` winding when the motor is first switched on, but turns off the start winding when the motor achieves sufficient running speed, as indicated by the shift in phase of the current in the motor's `run` winding. For bi-directional motors with two start windings, the microprocessor can apply current to either start winding.

Abstract: A processor system comprising a control module (10) and a variety of subsidiary modules or boards (11, 12, 13) connected to the control module by way of a bus and an analog connector line. The control module comprises an analog-to-digital input (16) for receiving a signal on the analog connector line (25) and each of the subsidiary modules comprising an analog element (24, 28, 29) and switch (23, 32, 33) connected for selectively switching the analog element to provide an analog signal on the analog connector line in response to a control signal received from the control module, thereby to identify the presence and/or type of the option board(s) installed in the system.

Abstract: A high power factor AC to DC converter with shunt regulation include first and second power converters for converting AC power to DC power; the first power converter receives and regulates input power from a power source and delivers a component of an output power to a load. The second power converter delivers another component of the output power to the load. The first power converter includes a unidirectional power output connected to the load.

Abstract: A compact, high frequency, zero voltage switching quasi-resonant converter with a multi-resonant, bi-polar switch includes a resonant switch (S), a first diode (D.sub.p) in parallel with the switch (S), a second diode (D.sub.s)in series with the switch (S), first (C.sub.r1) and second (C.sub.r2) resonant capacitors and a resonant inductor (L.sub.r). The first resonant capacitor (C.sub.r1) is operatively connected to the resonant switch (S) such that any voltage change across the first resonant capacitor (C.sub.r1) necessitates a corresponding voltage change across the resonant switch (S). The second resonant capacitor (C.sub.r2)is operatively connected to the second diode (D.sub.s) such that any voltage change across the second resonant capacitor (C.sub.r2) necessitates a corresponding voltage change across the second diode (D.sub.p). The resonant inductor (L.sub.r) is operatively connected in series with the resonant switch (S) such that any current change through the resonant inductor (L.sub.