Abstract: A damper device that suppresses arc discharge between electrodes generated by bubbles in an electro-rheological fluid, includes an inner tube housed in an outer tube forming an outer shell of a damper device. An electrode tube is arranged between the outer tube and the inner tube. An electro-rheological fluid is sealed in the outer tube. The inner tube and the electrode tube constitute a cathode and an anode, respectively, and apply a voltage to the electro-rheological fluid located between the inner tube and the electrode tube. An insulating layer is provided on a surface of the electrode tube on a side facing the inner tube or on a surface of the inner tube on a side facing the electrode tube. When a maximum voltage applied to the electro-rheological fluid is Vmax (V), a thickness t (m) of the insulating layer is set to satisfy Formula (1).

Abstract: A suspension control device including an electrorheological damper, a high voltage output circuit, a connection portion, and a control unit. The electrorheological damper includes a cylinder sealingly containing electrorheological fluid, a piston, a piston rod, and a positive electrode provided in a portion through which a flow of the electrorheological fluid is generated by a slide of the piston in the cylinder, and configured to apply a voltage to the electrorheological fluid. The connection portion includes an electrode connection portion configured to connect the high voltage output circuit and the positive electrode to each other, and a ground connection portion configured to connect the cylinder and a ground to each other. A resistor member, which has a resistance value set to a load resistance value of the electrorheological fluid in a regular-use temperature range of the electrorheological damper, is provided between the electrode connection portion and the ground connection portion.

Abstract: A damper device that suppresses arc discharge between electrodes generated by bubbles in an electro-rheological fluid, includes an inner tube housed in an outer tube forming an outer shell of a damper device. An electrode tube is arranged between the outer tube and the inner tube. An electro-rheological fluid is sealed in the outer tube. The inner tube and the electrode tube constitute a cathode and an anode, respectively, and apply a voltage to the electro-rheological fluid located between the inner tube and the electrode tube. An insulating layer is provided on a surface of the electrode tube on a side facing the inner tube or on a surface of the inner tube on a side facing the electrode tube. When a maximum voltage applied to the electro-rheological fluid is Vmax (V), a thickness t (m) of the insulating layer is set to satisfy Formula (1).

Abstract: Provided is a power converter for converting a DC input voltage to a DC output voltage and outputting the DC output voltage to a load, including: a discharge resistor which discharges electric charges accumulated in the load, a discharge switch which switches an electric conduction state of the discharge resistor; and a discharge controller which controls the discharge switch so that the output voltage becomes a predetermined target voltage, wherein the discharge controller controls the discharge switch to cut off electric conduction of the discharge resistor when the output voltage is lower than a predetermined threshold voltage that is higher than the target voltage, and wherein the discharge controller corrects the threshold voltage in response to a temperature change of the load.