A switching circuit (20) comprising first and second switch terminals (2,3) and a switch (21). The switch (21) comprises a first bipolar transistor (22), having a collector connected to the first switch terminal (2) and an emitter connected to the second switch terminal (3), and a second bipolar transistor (23), having an emitter connected to the first switch terminal (2) and a collector connected to the second switch terminal (3). The switch (21) can be turned on by supply of a control current ...

A system for detecting the transmission direction of a signal on a two-say transmission line, in which a switch is inserted in the two-way transmission line while a signal detector is connected to the two-way transmission line at one side of the switch. Two signal detectors may be connected to the two-way transmission line at both sides of the switch respectively. If the switch has two selected contacts, the two signal detectors are connected to the selected contacts respectively. The switch is ...

A differential current distributing circuit includes a first current path including a first resistor, collector-emitter path of a first transistor of first conductivity type and emitter-collector path of second conductivity type which are connected in series between the output terminal of a constant current source and a first current output terminal and a second current path including a second resistor, collector-emitter path of a third transistor of first conductivity type and emitter-collector...

The signal path between the input and output of a baseband video switch has a control point to which a signal representative of a switch control signal and a switchable constant current source are coupled. A pair of diodes and a switchable, high impedance buffer are disposed in series between the input terminal and the control point. A diode and a switchable driver are connected in series between the control point and the output terminal. A biasing arrangement responsive to the control signal bi...

This invention relates to a drive circuit coupled to electrical devices, which may be semiconductors, connected in parallel in a circuit network. The electrical devices have distinct total on-time periods when they are simultaneously energized. The circuit network has a source of power coupled through the parallel connected devices to a load. The drive circuit includes a signal source coupled respectively through a time adjustable circuit to a first electrical device and to a second electrical d...

A power transistor switch for switching high-amperage, direct-current through a low forward impedance, consisting of a transformer which couples a control pulse through separate multifilar secondary windings to each base element of a plurality of transistors. The utilization of multiple junction transistor geometry results in a rapid transition, i.e., low transition time consistent with a low forward impedance and cost savings because of the inherent economies in multiple junction transistors, w...

There is disclosed herein a redundant carrier frequency selection arrangement for an FDM communication system. The selection arrangement includes a source of n pairs of carrier frequencies, where n is an integer including one. Each carrier frequency of one pair of the n pairs of carrier frequencies are equal and the carrier frequency of each pair of the n pairs of carrier frequencies are different. n plurality of FDM communication equipment requiring a carrier are coupled to the source of n pair...

A stamp unit 1 comprises a holder 4 which is to be set in a holder storage part 70 of a stamp manufacturing device for making a stamping surface on a stamp material 3 held in the holder 4. When the holder 4 is set in the storage part 70, the cam effect is generated between the positioning projection 77 of a fixing member 71 and a slant recess 43 of the holder 4, thereby positioning the holder 4 to a predetermined stamp making position in the storage part 70. In a state where the holder 4 is posi...

An improved structure of a stamp comprises a main body, a stamp body, a press cover and two rotating lids. The stamp body has an ink compartment and a cylindrical rod, a stamping surface on the bottom, and two protrusion rods on each lateral side. The ink compartment has a protrusion piece and a blockage protrusion. The main body has a bottom surface with few holes for the stamp body to go through. The press cover has a block piece in the inner side for clipping on the surface of the stamp body,...

A manual self-inking stamping device including a base for contacting material to be stamped, such base having a recess in which a self-inking stamp pad is supported for vertical movement with respect thereto. A depressable handle threadedly engages a shaft extending through the base from the stamp pad, and a movable member is disposed about the shaft for selective meshing engagement with the base at one end of the movable member and for engagement with the handle at the other end to lock the han...