Device for signalling a specific charge condition of an accumulator battery
AssigneeU.S. Philips Corporation
InventorJohannes Ijntema
Life of this patent
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Abstract
A device for signalling a specific charge condition of an accumulator battery (B) comprises a comparator circuit (C) for comparing the battery voltage (V.sub.B) with a reference voltage. A switching circuit (G.sub.2, G.sub.13) is controlled by the comparator circuit and an indicator (L.sub.1, L.sub.2, L.sub.s) is in turn controlled by the switching circuit. A memory circuit (FF) ensures that the indicator remains energized for a specific time interval after the apparatus has been switched off.
Claims15
A device for signalling a specific charge condition of an accumulator battery incorporated in a battery-powered apparatus, which device comprises a comparator circuit for comparing the battery voltage with a reference voltage, a switching circuit controlled by the comparator circuit into a first state when the battery voltage drops below a given voltage level, an indicator controlled by the switching circuit, and a memory circuit coupled to the switching circuit, said memory circuit including time delay means for maintaining the indicator energized for a specific time interval after the apparatus has been switched off provided the switching circuit is in the first state when the apparatus is switched off.
A device for monitoring the voltage of a battery used as an energy source in a battery-powered apparatus comprising:
- a comparator circuit for comparing the battery voltage with a reference voltage indicative of a minimum desired battery voltage level, said comparator circuit having an input coupled to the battery via a switching means that switches the apparatus on and off, a switching circuit, an indicator device controlled by said switching circuit to develop an alarm indication when the switching circuit is in a first state, means for coupling an output of the comparator circuit to an input of the switching circuit so as to control the switching circuit into the first state when the battery voltage falls below said minimum desired battery voltage level for a given time period, and a memory circuit responsive to an output of the coupling means for delaying the switching of the switching circuit from the first state to a second state for a specific time interval after said apparatus has been switched off by said switching means.
A battery-powered apparatus comprising:
- a battery,
- a load for energization by the battery,
- a device for monitoring the battery voltage comprising:
- a comparator circuit for comparing the battery voltage with a reference voltage indicative of a minimum desired battery voltage level, a switching circuit coupled to an output of the comparator circuit and controlled thereby into a first state when the battery voltage falls below said minimum desired battery voltage level, an indicator device controlled by said switching circuit to develop an alarm indication when the switching circuit is in said first state, and a memory circuit responsive to the output of the comparator circuit for delaying the switching of the switching circuit from the first state to a second state for a specific time interval after said apparatus has been switched off,
- and switching means for selectively connecting the battery to said load and to said monitoring device thereby to switch the apparatus on and off.
A device for monitoring the voltage of a battery used as an energy source in a battery-powered apparatus comprising:
- switching means for connecting said device to the battery as long as the apparatus is switched on, a comparator circuit for comparing the battery voltage with a reference voltage, a switching circuit controlled by the comparator circuit and an indicator controlled by the switching circuit, and a memory circuit coupled between the comparator circuit and the switching circuit, said memory circuit comprising time delay means for delaying the switching off of the indicator for a specific time interval after the apparatus has been switched off.
Dependencies are inferred from the claim text.