摘要:
A HVAC system (10) employs a gas valve (20) to supply gas for combustion within a heating portion (12) of the system. An exhaust (22) removes combustion products using a motor (28) driven exhaust fan (24). An apparatus (34) controls combustion and uses a sensor (36) for sensing the rotational speed of a motor shaft (26). A switch (T1) is responsive to sensed motor speed to open and close the valve, the valve being opened only if the motor is operating within a predetermined speed range. A first speed discriminator (48A) enables of the switch to open the valve when the motor speed exceeds a first predetermined value. A second speed discriminator (48B) disables the switch to close the valve when motor speed exceeds a second and higher predetermined speed which is indicative of a blocked exhaust, or a fan blade is loose. This latter action insures that a build-up of potentially dangerous exhaust gases cannot occur.
摘要:
A process for forming a buried contact (50) in a semiconductor device (20) which avoids etch damage to the substrate and forms a self-aligned, low resistance contact to a silicon substrate (22) is provided. After forming a contact opening (32) through overlying insulating and conducting layers (24, 28,30), a silicide region (40) is formed in the substrate at the contact surface (34) exposed by the contact opening (32). A refractory metal silicide which provides high etching selectivity to polysilicon is formed in the substrate at the contact surface (34) by either a blanket deposition of a refractory metal into the contact opening (32), or alternatively, by a selective deposition process using contact surface (34) as a nucleation site. In a preferred embodiment, a cobalt or tantalum silicide region (40) is formed in the substrate at the contact surface (34) and a conductive layer (42) is deposited and etched to form an interconnect (48) contacting the silicide region (40). The high etching selectivity obtainable between the conductive layer ( 42) and the silicide region (40) avoids damage to the substrate surface providing improved device performance.
摘要:
A metallic interconnect includes a fuse portion that is readily vaporized upon exposure to the radiant energy of a laser. A layer of optically absorptive material is formed on top of an aluminum based metallic interconnect and together they are formed by a photolithographic and etch technique into a fuse portion. A low energy laser having a Gaussian energy distribution focused on the absorptive layer produces heat in the absorptive layer. The heat is transferred to the underlying aluminum based interconnect. The concentration of energy made possible by the absorptive layer allows the low energy laser to blow the fuse thereby producing an electrical open in the interconnect without damaging surrounding silicon substrate and/or polysilicon structures below or nearby the metal fuse.
摘要:
A method of fabricating hollow square inner conductors having precise outer dimensions is disclosed. A first "u" shaped slot (10) is machined in a base plate (12) and a cover plate (16) is then brazed to the sloted surface (18). The cover plate (16) is machined to provide a first wall (20) of desired thickness. Second and third slots (22, 24) are machined in the base plate (12) parallel to the first slot (10) on opposite sides thereof to provide second and third walls (26, 28) of the hollow conductor (38). A sacrificial metal (30) having a melting point below that of the base plate metal is cast into the second and third slots (22, 24). A fourth wall (36) is formed by machining material from the base plate face (32) opposite the slotted surface (18). The sacrificial metal (30) is then removed to provide the hollow inner conductor (38) having precise outer dimensions (A, B).
摘要:
A slide mechanism for use in transporting a stereoscope along a horizontal support arm of a photogrammetric instrument includes a member slidably mounted to a pair of support tracks cantilevered to the support arm. A clamping mechanism is used to lock the slide member in a first predetermined position on the support tracks and is unlockable to enable the slide mechanism to be moved along the support tracks to a second position.
摘要:
A desk top work support device having a base with an inclined primary work surface, and having a secondary work support member positioned above the primary work surface. The secondary work support member is pivotally mounted on the base to provide a preset forward position for close reading, and a preset rearward position for secondary reference tasks wherein the secondary work support member does not interfere with access to the primary work surface. The pivoting linkage provides different inclinations for the secondary work support member with respect to the primary work surface in said forward and rearward positions to permit optimum utilization of remote light sources. The secondary work support member has a support bar, and removable work holders which may be slidably engaged within the base and are retained therein by the secondary work support bar when it is in its rearward position.
摘要:
A truck mounted extendable flexible conveyor for use in loading and unloading truck cargo. When the conveyor is not in use, it is collapsed and securely stored in a vertical position in a rear corner of the truck. For use the conveyor is pulled down by the driver to a horizontal position and then extended in a straight or curved direction as required. One end of the conveyor is pivotally mounted on a shaft attached to the truck, with coil spring means extending between the conveyor and a stationary mounting plate to assist in movement of the conveyor between stored and use positions.
摘要:
A cutting apparatus is disclosed which includes a cutter knife which is reciprocally moveable along a path of travel; a track member mounted adjacent to the cutter knife and which mechanically cooperates with the cutter knife so as to define, at least in part, a first non-cutting position, and a second cutting position for the cutter knife; and a magnet is mounted in a location on the track member and which releasably, magnetically restrains the cutter knife when the cutter knife is in the first non-cutting position.
摘要:
A reciprocally moveable cutting knife is described and which includes an elongated main body having a first, and an opposite, second end for engaging an object of interest; and a protrusion is made integral with the elongated main body and which extends outwardly from a plane which is defined by the outside facing surface of the main body, and which inhibits an adhesion from being created between the outside facing surface of the elongated main body, and the respective sidewalls of a knife guidance track when a source of water wets the outside surface of the elongated main body and the spaced sidewalls of the knife guidance channel.
摘要:
3-D ICs (18, 18′, 90) with integrated passive devices (IPDs) (38) having reduced cross-talk and high packing density are provided by stacking separately prefabricated substrates (20, 30, 34) coupled by through-substrate-vias (TSVs) (40). An active device (AD) substrate (20) has contacts on its upper portion (26). An isolator substrate (30) is bonded to the AD substrate (20) so that TSVs (4030) in the isolator substrate (30) are coupled to the contacts (26) on the AD substrate (20), and desirably has an interconnect zone (44) on its upper surface. An IPD substrate (34) is bonded to the isolator substrate (30) so that TSVs (4034) therein are coupled to the interconnect zone (44) on the isolator substrate (30) and/or TSVs (4030) therein. The IPDs (38) are formed on its upper surface and coupled by TSVs (4034, 4030) in the IPD (34) and isolator (30) substrates to devices (26) in the AD substrate (20). The isolator substrate (30) provides superior IPD (38) to AD (26) cross-talk attenuation while permitting each substrate (20, 30, 34) to have small high aspect ratio TSVs (40), facilitating high circuit packing density and efficient manufacturing.