In certain embodiments, an assembly has intermediate pods magnetically, but not galvanically, coupled along an electrically conductive cable. Each pod has a magnetic core surrounding and inductively coupled to the cable and one or more coils inductively coupled to the magnetic core. The pod transmits, for example, outgoing current pulses on the cable by inducing electrical signals in the cable using a transmitter coil and the magnetic core. In addition, the pod repeats, for example, incoming current pulses on the cable by inducing electrical signals in the cable using the transmitter coil and the magnetic core, based on electrical signals induced in a receiver coil via the magnetic core by the incoming current pulses. Such an assembly can function as a data collection system for scientific research and/or as an early-warning system for events, such as earthquakes and tsunamis, without having to modify the cable itself.

In certain embodiments, an assembly has intermediate pods magnetically, but not galvanically, coupled along an electrically conductive cable. Each pod has a magnetic core surrounding and inductively coupled to the cable and one or more coils inductively coupled to the magnetic core. The pod transmits, for example, outgoing current pulses on the cable by inducing electrical signals in the cable using a transmitter coil and the magnetic core. In addition, the pod repeats, for example, incoming current pulses on the cable by inducing electrical signals in the cable using the transmitter coil and the magnetic core, based on electrical signals induced in a receiver coil via the magnetic core by the incoming current pulses. Such an assembly can function as a data collection system for scientific research and/or as an early-warning system for events, such as earthquakes and tsunamis, without having to modify the cable itself.

An attenuator having an impedance that is controllable by a first setpoint signal is coupled to a transmission line. A matching circuit having an impedance that is controllable by a second setpoint signal is also coupled to the transmission line. A transformer circuit block also coupled to the transmission line has a complex impedance. A control circuit sets the first and second setpoint signals so as to control a conjugate impedance relationship between the variable impedances presented by the attenuator and matching circuit relative to the complex impedance of the transformer circuit.

An attenuator having an impedance that is controllable by a first setpoint signal is coupled to a transmission line. A matching circuit having an impedance that is controllable by a second setpoint signal is also coupled to the transmission line. A transformer circuit block also coupled to the transmission line has a complex impedance. A control circuit sets the first and second setpoint signals so as to control a conjugate impedance relationship between the variable impedances presented by the attenuator and matching circuit relative to the complex impedance of the transformer circuit.

A noise filter is provided with a filter circuit including a first condenser and a second condenser; the first condenser and the second condenser are connected in parallel with each other by a first wiring lead for connecting one terminal of the first condenser with one terminal of the second condenser and a second wiring lead for connecting the other terminal of the first condenser with the other terminal of the second condenser; the first wiring lead and the second wiring lead are arranged in such a way as to intersect each other odd-number times.

A noise filter is provided with a filter circuit including a first condenser and a second condenser; the first condenser and the second condenser are connected in parallel with each other by a first wiring lead for connecting one terminal of the first condenser with one terminal of the second condenser and a second wiring lead for connecting the other terminal of the first condenser with the other terminal of the second condenser; the first wiring lead and the second wiring lead are arranged in such a way as to intersect each other odd-number times.

An attenuator having an impedance that is controllable by a first setpoint signal is coupled to a transmission line. A matching circuit having an impedance that is controllable by a second setpoint signal is also coupled to the transmission line. A transformer circuit block also coupled to the transmission line has a complex impedance. A control circuit sets the first and second setpoint signals so as to control a conjugate impedance relationship between the variable impedances presented by the attenuator and matching circuit relative to the complex impedance of the transformer circuit.

An attenuator having an impedance that is controllable by a first setpoint signal is coupled to a transmission line. A matching circuit having an impedance that is controllable by a second setpoint signal is also coupled to the transmission line. A transformer circuit block also coupled to the transmission line has a complex impedance. A control circuit sets the first and second setpoint signals so as to control a conjugate impedance relationship between the variable impedances presented by the attenuator and matching circuit relative to the complex impedance of the transformer circuit.

A signal transmission system includes: a switch component, a first choke component, a first conductive path and a second choke component that are connected in series between a power wire and a load; a third choke component and a resonant circuit that are connected in series between another power wire and a common node of the switch component and the first choke component; a second conductive path connected between the load and a common node of the third choke component and the resonant circuit; and a control block. Under control of the control block, a magnetic core of each choke component reaches magnetic saturation when the switch component does not conduct, and operates at magnetic saturation when the switch component conducts.

A signal transmission system includes: a switch component, a first choke component, a first conductive path and a second choke component that are connected in series between a power wire and a load; a third choke component and a resonant circuit that are connected in series between another power wire and a common node of the switch component and the first choke component; a second conductive path connected between the load and a common node of the third choke component and the resonant circuit; and a control block. Under control of the control block, a magnetic core of each choke component reaches magnetic saturation when the switch component does not conduct, and operates at magnetic saturation when the switch component conducts.