Method and apparatus for charging lead-acid-accumulators

Claim 3

A method according to claim 1, characterized in that the linear characteristic (3,302) followed above the gassing voltage level has an inclination (a) of about 0.2 V/I 5 .

Claim 4

Apparatus for charging lead-acid-accumulators, where the charging current above the charging voltage level at which gassing occurs decreases with increasing charging voltage according to a mainly linear characteristic, and which is provided with a controllable charging current source, a current sensor for providing a first signal in proportion with the charging current, a voltage sensor for providing a second signal in proportion with the charging voltage, and a control device coupled to the sensors and to the charging current source for controlling the charging process, characterized in that the control device is furnished with at least one converter device (70,80,150) for converting the first signal (50,55) and the second signal (60,65) to an indication signal (160) which is constant to the extent that the charging current and the charging voltage are following the linear characteristic (3,302), and with at least one regulating device (30,40,130) which is configured to provide, by comparing the indication signal (160) with a reference signal (132), a regulating signal for the charging current source (20) such that the charging current and the charging voltage at any time are corrected in accordance with the linear characteristic (3,302).

Claim 5

Apparatus for charging lead-acid-accumulators, where the charging current above the charging voltage level at which gassing occurs decreases with increasing charging voltage according to a mainly linear characteristic, and which is provided with a controllable charging current source, a current sensor for providing a first signal in proportion with the charging current, a voltage sensor for providing a second signal in proportion with the charging voltage, and a control device coupled to the sensors and to the charging current source for controlling the charging process, characterized in that the control device is furnished with at least one converter device (70,80,150) for converting the first signal (50,55) and the second signal (60,65) to an indication signal (160) which is constant to the extent that the charging current and the charging voltage are following the linear characteristic (3,302), and with at least one regulating device (30,40,130) which is configured to provide, by comparing the indication signal (160) with a reference signal (132), a regulating signal for the charging current source (20) such that the charging current and the charging voltage at any time are corrected in accordance with the linear characteristic (3,302).

Claim 6

Charging apparatus according to claim 3, characterized in that the converter device (70,80,150) is configured to generate a weighed sum of the first signal (50,55) and the second signal (60,65), and to generate the indication signal (160,V W ) in proportion therewith, such that the inclination (a) of the linear characteristic (3,302) is determined by the weights of the signals in the summation mainly.

Claim 7

Charging apparatus according to claim 4, characterized in that the converter device (70,80,150) is provided with a first voltage generator (230,260) for converting the first signal (50,55) to a first voltage (263) in proportion therewith, a second voltage generator (250) for converting the second signal (60,65) to a second voltage (253) in proportion therewith, and two resistances (R 1 ,R 2 ) connected in series and each coupled to one of the said voltages (253,263) at its terminal, remote from the connection point (290) between the resistances, and that the regulating device (30,40,130) is coupled to receive the voltage at the connection point (290) between the resistances (R 1 ,R 2 ) as indication signal.

Claim 8

Charging apparatus according to claim 5, characterized in that the first voltage generator (230,260) is provided with an adjusting device (230) for adjusting the conversion factor between the first signal (50,55) and the first voltage (263) in such a way that both the charging current and the inclination of the linear characteristic may be simultaneously adjusted to accumulators of different capacity by operating the adjusting device (230).

Claim 9

Charging apparatus according to claim 6, characterized in that the adjusting device (230) is placed on an operating panel (10) as to be manually operable.

Claim 10

Charging apparaatus according to anyone of claims 5 to 7, characterized in that each voltage generator consists of an operational amplifier (250,260) and where in the signal is supplied to a non-inverting input terminal (251,261) and the voltage is collected from an output terminal (253,263) which is connected with an inverting input terminal (252,262) of the operational amplifier (250,260).

Claim 11

Charging apparatus according to claim 8, characterized in that first signal is supplied to the non-inverting input terminal (261) of the first voltage generator (260) via a contact lever of a potentiometer (230) serving as adjusting device.