Patent ID: 8274174
Filing Date: 2012-09-25
Classification: B60R,H02J

Abstract:
1. A circuit arrangement for supplying power to a control device in a motor vehicle, comprising: a first power supply line coupled to a first voltage source and having a first ground line; and a second power supply line switchably coupled to a second voltage source via a first switch and having a second ground line; wherein the control device includes at least five pins, a controllable switch, and a logic circuit, wherein each power supply line and ground line is respectively connected to a respective pin of the control device, wherein the logic circuit includes a first control input connected to the second power supply line, a second control input connected to the first ground line, and a third control input connected to the second ground line, wherein the first ground line and the second ground line are switchably connected by the controllable switch, and wherein responsive to a closing of the first switch, the logic circuit checks a first voltage difference between the first and the second control inputs, and checks a second voltage difference between the first and the third control inputs and closes the controllable switch when the first voltage difference falls below a threshold value and the second voltage difference corresponds to a voltage difference of an on-board voltage, and wherein one of the at least five pins is coupled to a third line when an ignition switch of the motor vehicle is on, so that voltage is applied to the third line.