Patent attributes
The disclosed detection circuit for a seatbelt apparatus may include an attachment detection switch, first and second resistance elements, and an LED. The resistance value of the first resistance element may be set to a value which allows a current smaller than the maximum current value which cannot turn the LED on to flow through the LED when the attachment detection switch is in an OFF state. The resistance values of the first and second resistance elements can be set to values which allow a current larger than the minimum current value which can turn the LED on to flow through the LED when the attachment detection switch is in an ON state. A monitoring circuit may determine whether or not the tongue on the seat is attached to the buckle.