Patent ID: 9417271
Filing Date: 2016-08-16
CPC Classification: G01R

Claim Text:
1. A voltage detection device configured to be connected to a power supply device of a vehicle and to detect a decrease in an output voltage of the power supply device, the voltage detection device comprising: a first voltage-dividing circuit configured to divide the output voltage of the power supply device with a predetermined ratio; a first constant-voltage circuit configured to convert the output voltage of the power supply device into a predetermined voltage; a second constant-voltage circuit configured to convert the output voltage of the power supply device into a predetermined voltage, which is lower than an output voltage of the first constant-voltage circuit; a comparator configured to receive an output voltage of the first voltage-dividing circuit and an output voltage of the second constant-voltage circuit; and a detection circuit configured to receive the output voltage of the first voltage-dividing circuit, the output voltage of the first constant-voltage circuit, and an output voltage of the comparator and to detect the decrease in the output voltage of the power supply device, wherein the detection circuit detects a decrease in the output voltage of the power supply device in a higher-voltage region of a detection voltage range of the detection circuit, based on the output voltage of the first voltage-dividing circuit and the output voltage of the first constant-voltage circuit, and the detection circuit detects a decrease in the output voltage of the power supply device in a lower-voltage region of the detection voltage range of the detection circuit, based on the output voltage of the comparator.