US 4,284,944 AGranted

Battery charging device having battery state indicating function

AssigneeMatsushita Electric Works, Ltd.

InventorsKouichi Iwanaga, Hiromi Kakumoto

Life of this patent

Estimating the term…

Loading patent…

Abstract

Battery charging device having a function of indicating in sounds at least one of charging and discharging states of a storage battery, specifically adapted to be incorporated in battery operated electric implements. During charge operation, a charging circuit oscillatorily generates from a rectified direct current of commercial AC source current a high frequency charging voltage, of which oscillation becomes intermittent with varying intervals after a predetermined battery charge level is reached, whereby a charge complete detecting circuit causes a sound generating device to be operated to sound discriminatively initial and final charge complete indications responsive to the varying intervals. During discharge operation, a charge remind detecting circuit provides an output to the sound generating means only after a predetermined discharge level is reached, to cause the means device to be operated to sound a charge remind indication.

Claims7

Dependent claims

A battery charging device having a battery state indicating function comprising:

a rectifier for converting an AC source current into a direct current;
a high frequency charging circuit including a transistor, a transformer having windings respectively disposed in the collector, base and emitter circuits of said transistor, and a rectifying diode connected in series between said emitter circuit transformer winding and the emitter of said transistor, wherein a battery to be charged is connected in parallel with said series connected of said diode and said emitter circuit winding;
detecting means responsive to the charge level of a battery being charged, for producing an output signal when a predetermined level is reached;
a control circuit responsive to said detecting means for causing said charging circuit to produce an intermittent charging voltage when said predetermined charge level is reached;
and
means responsive to said level detecting means for intermittently generating a sound when said predetermined level is reached, said sound generating means being responsive to the level of charge of the battery such that the length of the period between each generated sound, relative to the length of each generated sound, is varied in dependence upon the charge level.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/084,058Filed 12 Oct 1979
Priority: JP 53/12549112 Oct 1978
Granted: 18 Aug 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

H01M 10/44
Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells: methods for charging or discharging
H02J 7/02
Circuit arrangements for charging or discharging batteries or for supplying loads from batteries: for charging batteries from AC mains by converters
H02J 7/61
Including safety or protection arrangements: against overcharge
H02J 7/63
Including safety or protection arrangements: against overdischarge