Abstract: An insulation resistance detection device detects a voltage at a connection point between a coupling capacitor and a resistance in the case where a frequency signal is outputted to the resistance, and detects an insulation resistance between a ground portion and a power supply path based on a moving average value of a detection voltage. The insulation resistance detection device includes a first determination unit, a resistance detection unit, and a second determination unit. In response to a determination that the pulsation of the detection voltage is attenuated, the resistance detection unit detects the insulation resistance based on, instead of a first moving average value, a second moving average value calculated by using the detection voltage in a second range including a smaller number of detection voltages than in the first range.

Abstract: In an insulation resistance detection apparatus, a voltage determiner determines whether a detection voltage, which has changed by at least a preset value, becomes stable at around a changed voltage value. A resistance determiner determines a value of an insulation resistance between a ground portion and a power-supply path based on a currently sampled value of the detection voltage instead of a moving average in response to determination that the detection voltage, which has changed by at least the preset value, becomes stable at around the changed voltage value.

Abstract: In an insulation resistance detection apparatus, a voltage determiner determines whether a detection voltage, which has changed by at least a preset value, becomes stable at around a changed voltage value. A resistance determiner determines a value of an insulation resistance between a ground portion and a power-supply path based on a currently sampled value of the detection voltage instead of a moving average in response to determination that the detection voltage, which has changed by at least the preset value, becomes stable at around the changed voltage value.

Abstract: An insulation resistance detection device detects a voltage at a connection point between a coupling capacitor and a resistance in the case where a frequency signal is outputted to the resistance, and detects an insulation resistance between a ground portion and a power supply path based on a moving average value of a detection voltage. The insulation resistance detection device includes a first determination unit, a resistance detection unit, and a second determination unit. In response to a determination that the pulsation of the detection voltage is attenuated, the resistance detection unit detects the insulation resistance based on, instead of a first moving average value, a second moving average value calculated by using the detection voltage in a second range including a smaller number of detection voltages than in the first range.

Abstract: A heater controller and heater control method is disclosed. The hater controller includes a detector, a determination circuit, a limiting circuit, a selection circuit, and a driving circuit. The detector detects a temperature of the heating object, which is heated by the heater. The determination circuit determines turn-on ratio for the heater for every control cycle of AC voltage, based on the surface temperature of the heating object and a target temperature of the heating object. The limiting circuit limits the turn-on ratio of current control cycle when the control method of previous control cycle is phase control. The selection circuit selects control pattern to control the heater, based on the turn-on ratio, and the driving circuit applies a heater driving signal to the heater.

Abstract: A heater controller and heater control method is disclosed. The hater controller includes a detector, a determination circuit, a limiting circuit, a selection circuit, and a driving circuit. The detector detects a temperature of the heating object, which is heated by the heater. The determination circuit determines turn-on ratio for the heater for every control cycle of AC voltage, based on the surface temperature of the heating object and a target temperature of the heating object. The limiting circuit limits the turn-on ratio of current control cycle when the control method of previous control cycle is phase control. The selection circuit selects control pattern to control the heater, based on the turn-on ratio, and the driving circuit applies a heater driving signal to the heater.