Patent ID: 6774607
Filing Date: 2004-08-10
Classification: H02H,H02J

Abstract:
A charger for an accumulator, comprising a power source, a charging device connected by input terminals to the power source and by output terminals to the accumulator, the power supplied by the power source being converted from an AC voltage to a DC voltage and the converted power being delivered by the output terminals to the accumulator, and an output side protection circuit for overload protection and polarity reversal protection against incorrect polarity of the accumulator, the protection circuit being connected to one of the output terminals and including a first switching element connected to the one output terminal and a negative potential of the charging device and establishing a connection between the one output terminal and the negative potential if a correct, negative polarity appears at the one output terminal, and interrupting the connection if an incorrect, positive polarity appears at the one output terminal, a control node of the first switching element connected by a conductor to a second switching element to which the negative potential of the charging device is connected; and the charging device further including a control device having a control input terminal and a control output terminal, the control input terminal being connected with a positive potential of a supply voltage source so that the second switching element is activated if an incorrect positive polarity appears at the one output terminal or too high a current flows through a conductor between the one output terminal and a control node of the second switching element, causing the first switching element to be deactivated, due to the connection established by the second switching element between the supply voltage source and the negative potential of the charging device, the switched state of the first switching element being determined by the switched state of the second switching element, and the control output terminal being connected to the control node of the second switching element for controlling the further switching element.