Drive device
AssigneesAutonetworks Technologies, Ltd., Sumitomo Wiring Systems, Ltd., Sumitomo Electric Industries, Ltd.
InventorJunpei HORII
Life of this patent
Estimating the term…
Abstract
In a drive device, a drive circuit drives light-emitting diodes by alternately switching a switch on and off. A voltage detection unit detects a battery voltage value at a positive terminal of a battery. A control unit calculates a duty on the basis of the value detected by the voltage detection unit and changes a duty for switching the switch on and off to the calculated duty. If the battery voltage value is the value detected by the voltage detection unit, when the switch is on, the duty calculated by the control unit is the ratio of a target current value to the value of current flowing in the light-emitting diodes.
Claims7
A drive device comprising a drive unit, the drive unit switching a switch, one end of which is connected to one end of a battery, on and off in an alternating manner to drive a light-emitting diode disposed in a current path of current flowing from another end of the switch, the device further comprising:
- a voltage detection unit that detects a battery voltage value at the one end of the battery;
- a calculation unit that calculates a duty on the basis of a detection value detected by the voltage detection unit;
- and
- a changing unit that changes a duty of the switching of the switch on and off to the duty calculated by the calculation unit,
- wherein when the battery voltage value is a detection value detected by the voltage detection unit, the duty calculated by the calculation unit is a ratio of a target current value to the value of current flowing in the current path when the switch is on.
Dependencies are inferred from the claim text.