摘要:
A device for detecting the short circuiting of the switches of a converter circuit arrangement is disclosed. The device is magnetically coupled to the current limiter coil and comprises a conductor loop which is preferably arranged at the end of the current limiter coil. On short circuiting, a voltage is induced in the conductor loop. This voltage is converted in a detection circuit into a voltage pulse and fed to an evaluation logic circuit. In the evaluation logic circuit, the period of the induced voltage pulse is evaluated and, if appropriate, load-relieval actuation is initiated.
摘要:
The input and/or output device for process data has a mounting rack (1), as well as a plurality of modules (2) fastened on the mounting rack (1). A process connector (4) can be inserted into each of the modules (2) on the front side in each case. Each module (2) has a circuit board (17) which is arranged in a housing (8), as well as a terminal strip (18) which is connected non-positively to the process connector (4). The terminal strip (18) serves to receive contact pins (26) which interact with contacts of the process connector (4). The input and/or output device is intended to demonstrate a high degree of operational reliability even in the case of a high level of mechanical and electromagnetic stresses. This is achieved in that the module housing (8) is predominantly formed from metal plate and has lugs (21, 22, 23) formed out of the metal plate which serve to carry the circuit board (17), some of which lugs are electroconductively connected to a conductor track (32) of the circuit board (17), and in that the module housing (8) is in contact with a metal part of the mounting rack (1) which is at ground potential.
摘要:
An electronic circuit arrangement is disclosed for converting an input voltage signal having a first voltage level into an output signal having a second voltage level. An input unit is provided for inputting the input voltage signal at the first voltage level, while an output unit is arranged for outputting the output signal at the output of the electronic circuit arrangement. A threshold value comparison unit serves for comparing the first voltage level of the input signal with a switch-on threshold value. The circuit arrangement furthermore contains an input impedance changeover unit for changing over an input impedance of the circuit arrangement from a low value to a high value after a predetermined delay duration after the first voltage level of the input voltage signal exceeded the switch-on threshold value.
摘要:
An arrangement of RFID antennas, comprises a first antenna having a beam centered at a first angle right of a center point and a second antenna having a beam centered at a second angle left of the center point, where the two beams being narrower than 70 degrees. This arrangement of RFID antennas enables division of the azimuth read zone of a reader into two or more zones which can provide a highly reliable indication of direction from the processing of RF tag reads.
摘要:
An antenna device includes a directional antenna and a support member that supports the antenna. The support member includes one or more fixed supports on which the antenna device can be placed to provide for a desired antenna reception beam elevation angle.
摘要:
A multiple-mandrel ring rolling machine for producing a ring from a ring blank having a plurality of elongated mandrel rolls rotatably mounted on a rolling platform fixedly mounted to a frame for rotation relative thereto is disclosed. The mandrel rolls are axially displaceable relative to the rolling platform between a first position above the rolling platform for rolling a ring blank and a second position below the rolling platform.
摘要:
A channel letter has a rear surface for mounting against a raceway, wall, or a structure for supporting the signage, and sheet metal sides defining the figuration of the letter or shape to be depicted. A lighting element is positioned against the rear surface of the enclosure, and a lens is retained to the open front of the enclosure. The lens is secured with a retainer cap and a plurality of retainer clips. Each of the retainer clips comprises as least one side including an outwardly extending leg for retention with the retainer cap.
摘要:
An apparatus includes an antenna (e.g., a monopole), a first load, and a second load. The antenna, which extends substantially along an axis, has a first end and a second end. The first load is coupled to the antenna at the first end, while the second load is coupled to the antenna between the first end and the second end. Both the first and second loads are symmetrical with reference to the axis. The apparatus is arranged to operate in at least two frequency bands, such as the AMPS band from about 824 MHz to 894 MHz and the PCS band from about 1850 MHz to 1990 MHz.
摘要:
A radio frequency identification (RFID) read antenna is provided. The RFID antenna includes an aperture board having at least one opening and a dielectric patch element spaced a distance from the aperture. The RFID antenna further includes a quadrature coupler connected to the aperture board and configured to excite the dielectric patch element to generate RFID signals.
摘要:
A channel letter has a rear surface for mounting against a raceway, wall, or a structure for supporting the signage, and sheet metal sides defining the figuration of the letter or shape to be depicted. A lighting element is positioned against the rear surface of the enclosure, and a lens is retained to the open front of the enclosure. The lens is secured with a retainer cap and a plurality of retainer clips. Each of the retainer clips comprises as least one side including an outwardly extending leg for retention with the retainer cap.