Abstract: RF switches, for use with radio frequencies, are fast, and require practically no DC energy for maintaining the ON and OFF positions. The switches include a rectifier in series with a capacitor, or with another rectifier in a back-to-back position, or facing each other, or a transistor instead of these two, the rectifier and transistor having an adequate reverse recovery time, these elements being arranged between the RF power source and the load. An inductive element is disposed in series with either the elements of the switch or between the base of the transistor and ground. There may be provided a further diode in series with the inductive element and the switch and in the connection to ground.

Abstract: The present invention relates to an absorption chiller using water as refrigerant and aqueous lithium bromide or the like as absorbant, provided with one or more horizontal tubes through the absorber serving as conduits for water, subdivided into a plurality of individual compartments by means of seals substantially perpendicular to said tube or tubes, a purge line and a drain line being provided leading from each of the compartments. According to one embodiment, a liquid seal is provided for each of the compartments preventing horizontal flow of water vapor and non-condensables.

Abstract: The present invention relates to lithium cells of the wound electrode high power type, with reduced short-circuit current, wherein the short-circuit current is reduced by the use of an electrolyte of reduced concentration or activity, or by the use of an electrode of lithium alloyed with magnesium, calcium, aluminum, cadmium or silicon.

Abstract: According to the present invention there is provided a current detector useful in interconnection of an automatic telephone exchange with a central office via TIP and RING leads and comprising; rectifying apparatus coupled to the TIP lead for rectifying at least a portion of the current flowing therealong of either polarity; and detector apparatus receiving the rectified output of the rectifying means and providing a DC output signal indicating current passage along the TIP lead.

Abstract: The present invention relates to a chiller of the type using water as refrigerant and aqueous lithium bromide or the like as absorbant, wherein 2-ethyl n-hexanol or a similar compound is used as additive to said solution to improve heat transfer in the absorber, comprising a separator for separating a large part of the additive from said solution, said separator being located between the exit of the lithium bromide solution from the absorber and between the heat exchanger in the conduit leading to the generator. According to one embodiment, the separator operates on gravity separation. According to one embodiment, the separator comprises a vessel large enough for substantially slowing down the velocity of flow of the solution, provided with inlet means at its lower part, outlet means at its upper part for a small part of the solution substantially enriched respective said additive, and an outlet at its lower part for the bulk of the solution, depleted of part of the additive.

Abstract: The present invention relates to a chiller of the type using water as refrigerant and aqueous lithium bromide or a similar compound as absorbant wherein non-condensables are purged with water vapor from the condenser to the evaporator, wherein means are provided for condensing part of the water vapor conveying the entrained non-condensables as this is conveyed to the evaporator. According to one embodiment, entrained non-condensables are contacted with a condenser tube so as to condense part of the water vapor.

Abstract: The present invention relates to a wideband VHF antenna of omnidirectional directivity, comprising a substantially vertical elongated structure consisting of an upper part consisting of a plurality of wires of different length, electrically insulated from each other, of a length of about one-fourth of the longest wave-length to about one-fourth of the shortest wave-length of the waveband, arranged with their contiguous parts parallel with each other and close to each other, and a lower part in the form of a coaxial structure, the lower ends of the said wires being connected with the inner wire of the said coaxial structure, said inner wire constituting an impedance multi-step transformer of at least two stages, said inner wire constituting the winding of at least one ferrite torroid forming an effective ground isolation, the outer conducting sheath of the coaxial structure constituting the lower part of the dipole, the impedance of the antenna being matched to that of the receiver and/or transmitter with whic

Abstract: A line circuit for connecting telephone subscriber terminals to a signal transmission network which includes constant current sources for driving the subscriber terminals and an isolated line transformer for connecting the terminals to the transmission network. The constant current sources include a pair of transistors with a mutual feedback loop for regulating the current in the transistors. An amplifier can be included in the feedback loop to further regulate the transistor current.

Abstract: A time division multiplex system is provided with a conference link to a common transmission highway. The conference link includes a plurality of incoming conference lines with in-gates disposed therein, and a plurality of outgoing conference lines with respective out-gates disposed therein. A common control containing a cyclic memory controls the in-gates for sequentially connecting the incoming conference lines to the common transmission highway during specific time slots, and controls the out-gates to connect an outgoing conference line to the common highway during a specific time slot to establish the conference connection. Each outgoing conference line is connected to a sample and hold circuit for reconstruction of the sampled signal transmitted thereto from the transmission highway, and thereafter to a common adder before being coupled to the incoming lines of the conference link.An operator's console is provided from which the conference connections are established.

Abstract: A battery charging and discharging system includes a charging circuit for charging a battery from supply mains and a first switching circuit responsive to a failure of the supply mains for switching the battery from the charging circuit to a discharge circuit which imposes a load thereon. A second switching circuit is thereafter responsive to the output of the battery to disconnect the load from the battery when the battery output falls below a predetermined level.