A method for signal transmission via an electrical power transmission pathway, said method consist of: electrically connecting a switch component to one of a first power wire and a second power wire, the switch component being electrically connected to a first choke component in series, the first and second power wires (W1, W2) cooperatively transmitting electrical power; building a first conductive path between the first choke component and a second choke component that is electrically connected to a load in series; electrically and respectively connecting a third choke component and a first resonant circuit to the other one of the first and second power wires (W1, W2) and a first common node of the switch component and the first choke component, the third choke component and the first resonant circuit being electrically connected in series; building a second conductive path between the load and a second common node of the third choke component and the first resonant circuit; and controlling the switch component to not conduct, and inducing an induced current (i induce) that is related to a load control signal for controlling operation of the load, and that flows through at least the first choke component, the first conductive path, the second choke component, the second conductive path and the first resonant circuit; wherein each of the first to third choke components (2, 3, 4) includes a magnetic core (22, 32, 42), and the magnetic core (22, 32, 42) of each of the first to third choke components (2, 3, 4) has a magnetic hysteresis characteristic corresponding to a magnetic hysteresis curve such that: when the switch component does not conduct, the induced current (i induce) does not cause the magnetic core (22, 32, 42) of any of the first to third choke components (2, 3, 4) to reach magnetic saturation; and when the switch component conducts, the electrical power provides a current (i conduct) that flows through the switch component, the first choke component, the first conductive path, the second choke component, the load, the second conductive path and the third choke component, and that causes the magnetic core (22, 32, 42) of each of the first to third choke components (2, 3, 4) to operate at magnetic saturation. electrically connecting a switch component to one of a first power wire and a second power wire, the switch component being electrically connected to a first choke component in series, the first and second power wires (W1, W2) cooperatively transmitting electrical power; building a first conductive path between the first choke component and a second choke component that is electrically connected to a load in series; electrically and respectively connecting a third choke component and a first resonant circuit to the other one of the first and second power wires (W1, W2) and a first common node of the switch component and the first choke component, the third choke component and the first resonant circuit being electrically connected in series; building a second conductive path between the load and a second common node of the third choke component and the first resonant circuit; and controlling the switch component to not conduct, and inducing an induced current (i induce) that is related to a load control signal for controlling operation of the load, and that flows through at least the first choke component, the first conductive path, the second choke component, the second conductive path and the first resonant circuit; wherein each of the first to third choke components (2, 3, 4) includes a magnetic core (22, 32, 42), and the magnetic core (22, 32, 42) of each of the first to third choke components (2, 3, 4) has a magnetic hysteresis characteristic corresponding to a magnetic hysteresis curve such that: when the switch component does not conduct, the induced current (i induce) does not cause the magnetic core (22, 32, 42) of any of the first to third choke components (2, 3, 4) to reach magnetic saturation; and when the switch component conducts, the electrical power provides a current (i conduct) that flows through the switch component, the first choke component, the first conductive path, the second choke component, the load, the second conductive path and the third choke component, and that causes the magnetic core (22, 32, 42) of each of the first to third choke components (2, 3, 4) to operate at magnetic saturation.