摘要:
A connector assembly includes a mother board (12), a mother receptacle (11), a daughter board (22), a daughter receptacle (21), and a connecting device (30) mounted between said two boards. The connecting device includes a number of fixing portions, a shroud (31) defining an insertion slot (313) and engageable with said two boards via the fixing portions, and an extender (32) inserted in the insertion slot. The extender defines a lower opening (322) mating with the mother receptacle and an upper opening (321) mating with the daughter receptacle.
摘要:
An electrical connector for connecting a sheet-like member includes terminals (2 or 2′) each comprising a base portion (20 or 20′), a bearing beam (21 or 21′) and a contact beam (22 or 22′) substantially parallel extending from the base portion; a housing (1) including an upper wall (11), a lower wall (12) and a rear wall, and having an inner surface defining a mouth (10) for receiving the sheet-like member and an exterior surface provided with a number of grooves (13) thereon, each groove comprising an upper groove (131) defined along the upper wall for accommodating the bearing beam, a lower groove (132) defined along the lower wall for accommodating the contact beam, and a rear groove defined on the rear wall for accommodating the base portion; and an actuator (3) pivotally engaging with the bearing beams for establishing electrical connection between the sheet-like member and the contact beams.
摘要:
An electrical connector (1) has a metal shield (3), a main housing (5), a pair of LEDs (6) received in the main housing, a subassembly (7) assembled to the main housing, a stacked Universal Serial Bus (USB) 4, and a molded assembly (2) assembled to the subassembly. Each LED (61, 62) has a plurality of leads (611, 621), a free end (612) of the middle lead of the LED is bent perpendicularly and extending horizontally thereafter below the other leads. The molded assembly comprising a plastic part (24), and a first and second connections (22, 23) insert molded in the plastic part. The plastic part has a pair of supporting posts (243) and a pair of positioning posts (245) extending from corresponding supporting posts. Each supporting post defines a channel (244) in a middle portion thereof.
摘要:
An electrical connector (1, 1′) straddle-mounted on an edge (20, 20′) of a printed circuit board (2, 2′) includes an insulative housing (10) having an elongated groove (11) for mating. A number of receiving channels (13) each used to receive a support subassembly (3, 3′) is formed adjacently to and communicated with the mating groove (11). The support subassembly includes a base (30, 30′) with signal terminals (5, 5′) and a grounding member (4, 4′) attached thereon. Every terminal includes an engaging end (51, 51′) exposed to the mating groove (11) and a tail end (52, 52′) extending out of the receiving channel (13). The grounding member includes a number of contacting legs (42, 42′) extending therefrom. A notch (34, 34′) with a thinned area is disposed on the base to define a separating portion (33, 33′) from the base. The notch is used to facilitate relocating the separating portion relative to the base. The separating portion of the base can be positioned between the tail ends of the terminals and the contacting legs of the grounding member to electrically insulate them from each other while the shape of the tail ends and the contacting legs are changeable for being mounted on another desired printed circuit board with a different thickness. The separating portion can be moved for the assembling of every terminal and the grounding member when they need to put together to form the support subassembly for being inserted into the housing.
摘要:
A straddle mount connector (1) includes a dielectric housing (2) defining a mating surface (200) and an opposite mounting surface (202), a pair of ground buses (4) and two rows of signal contacts (3) installed into the housing from the mounting surface. Each ground bus is accompanied with a carrier strip (46) and has solder tails (42) extending from the carrier strip. The ground bus has a number of fingers (460) extending from the carrier strip to define a number of parallel slits (462) between the fingers. The signal contacts have terminal portions (32) extending through the parallel slits, thereby keeping the signal contacts retained between the fingers of the ground bus.
摘要:
A printed circuit board (1) for a straddle mount electrical connector (2) includes a first side surface (10) and a second side surface (12) opposite to the first side surface. Each of the side surfaces has a front and a rear rows of conductive pads (14), (16) and the conductive pads in the front row are staggered with respect to the conductive pads in the rear row. A number of solder pastes (11), (13) are applied through a solder stencil (18) to the conductive pads wherein each solder paste corresponding to the conductive pad in the front row is narrower and longer than the conductive pad. The straddle mount electrical connector has staggered signal and grounding contacts (221), (222) respectively secured to the front and the rear rows of conductive pads of the printed circuit board.
摘要:
Chip carrier sockets (2) have terminals (4) provided therein, the terminals (4) comprising leg portions (34) with first resilient arms (18) and second resilient arms (20) pivotally attached thereto. The first resilient arms (18) have contact surfaces (26) provided on free end sections (22) thereof. The contact surfaces (26) are provided to electrically engage leads (6) of the chip carrier (8). A cover (12) is provided to cooperate with the chip carrier and to act as a protective handler for the chip carrier. Retention means are positioned on the chip carrier socket (2) to cooperate with the cover (12), thereby providing the contact force required to insure that a positive electrical connection is effected between the leads (6) and the terminals (4). The resilient configuration of the retention means insures that the retention means will not fail under normal stresses associated therewith.
摘要:
Radio frequency (RF) shields used with magnetic resonance imaging (MRI) apparatus may experience gradient field induced eddy currents and RF field induced eddy currents. These eddy currents can cause the RF shield to heat up at an undesirable rate. RF shields are designed to have a desired degree of RF shielding and a desired heating attribute. Design goals for RF shields include gradient field transparency and RF field opacity, both of which can be influenced by eddy currents. Example methods identify a gradient field that will induce eddy currents and identify an RF field that will induce eddy currents. If a region on the RF shield is identified where the desired heating attribute will not be achieved, then a pattern of axial cuts and azimuthal cuts can be made in the RF shield to reduce gradient eddy current heating in the RF shield while maintaining desired RF shielding.
摘要:
The present invention provides an apparatus for reducing acoustic noise in a magnetic resonance imaging device including passive shielding located outside the actively shielded gradient winding elements in order to reduce the magnitude of fields that spread outside the gradient coil assembly in unwanted directions and interact with the magnet cryostat or other metallic magnet parts, inducing eddy currents that cause consequent acoustic noise. The passive shielding elements are conducting layers located on the outer radius of the cylindrical gradient coil assembly in a cylindrical magnet system, conducting layers located at the ends of the gradient coil assembly in a cylindrical magnet system, and conducting layers located inside the actively shielded gradient winding inner elements in a cylindrical magnet system. The passive shielding could also be located on separate structures that are vibrationally isolated from the magnet cryostat. The actively shielded gradient winding can also be extended to portions at the ends of the actively shielded gradient winding and further to portions inside the inner radius of the inner portion of the actively shielded gradient winding. The actively shielded gradient windings and passive shielding should be designed concurrently in order to substantially optimize the gradient linearity and reduce the eddy currents generated in metallic parts of the magnetic resonance imaging system.
摘要:
In a magnetic resonance imaging apparatus, a main magnet assembly (12) produces a uniform magnetic field through an imaging region (14). An imaging region is defined within a subject by selecting gradient magnetic fields spatially encode the main magnetic field. A whole body birdcage radio frequency coil (26) excites magnetic resonance in dipoles of the subject. The resonance signals are received by the whole body coil (26) and by a second, local birdcage radio frequency coil (16). The first radio frequency coil (26) produces and is sensitive to a uniform radio frequency field in the imaging region (14) while the second radio frequency coil (28) is sensitive to a field that varies sinusoidally in space. From one radio frequency excitation, the two birdcage coils (26, 16) receive different sets of data with which to fill k-space, accelerating data collection.