State-of-charge indicator for voltage-regulated battery charger

Claim 2

In combination with voltage regulated battery charging apparatus of the type having a pair of output terminals to which a storage battery can be connected for charging, a pair of input terminals that provide a source of alternating current having a substantially constant peak voltage, a controlled rectifier which has a gate and which is connected to control flow of current between one of said input terminals and one of said output terminals, and regulating means which comprises a zener diode and which has connections with said gate, with said one input terminal and with the other output terminal, for causing the controlled rectifier to be forwardly conductive when the difference between voltage across the input terminals and voltage across the output terminals exceeds a predetermined value, means for indicating the state of charge of a battery connected with the output terminals, the last mentioned means comprising: A. a second zener diode; B. a device capable of producing a perceptible signal upon being electrically energized; and C. means connecting said device and the second zener diode in series with one another and across the output terminals, with the second zener diode being so connected and having such a zener value that it permits flow of energizing current through said device when voltage across the output terminals is high enough so that said difference remains substantially equal to said predetermined value.

Claim 3

The combination of claim 1, further characterized by: said second zener diode having a zener value lower than that of the first mentioned zener diode.

Claim 4

The combination of claim 1 wherein said device comprises a lamp bulb.

Claim 5

Signaling means for regulated battery charging apparatus, for indicating the state of charge of a storage battery that has its terminals connected with a pair of output terminals of said apparatus, said apparatus also having a pair of input terminals that provide a source of alternating current, a controlled rectifier connected between one of said input terminals and one of said output terminals and having a gate, and regulation means comprising a zener diode, said regulation means being so connected with said gate, said one input terminal and the other output terminal as to cause the controlled rectifier to be forwardly conductive whenever the difference between voltage across the input terminals and voltage across the output terminals exceeds a predetermined value, said signaling means comprising: A. a signaling device capable of producing a perceptible output upon being electrically energized; and B. means so connecting said signaling device across said output terminals as to cause the signaling device to be energized whenever voltage across the output terminals is at a level high enough so that said difference tends to remain substantially at said value, the last mentioned means comprising a second zener diode connected in series with the signaling device and arranged to prevent current flow through said device when voltage across the output terminals is below said level, said second zener diode having a zener voltage such as to pass energizing current through said device when voltage across the output terminals is at said level.

Claim 6

Signaling means for regulated battery charging apparatus, for indicating the state of charge of a storage battery that has its terminals connected with a pair of output terminals of said apparatus, said apparatus also having a pair of input terminals that provide a source of alternating current, a controlled rectifier connected between one of said input terminals and one of said output terminals and having a gate, and regulation means comprising a zener diode, said regulation means being so connected with said gate, said one input terminal and the other output terminal as to cause the controlled rectifier to be forwardly conductive whenever the difference between voltage across the input terminals and voltage across the output terminals exceeds a predetermined value, said signaling means comprising: A. a signaling device capable of producing a perceptible output upon being electrically energized; and B. means so connecting said signaling device across said output terminals as to cause the signaling device to be energized whenever voltage across the output terminals is at a level high enough so that said difference tends to remain substantially at said value, the last mentioned means comprising a second zener diode connected in series with the signaling device and arranged to prevent current flow through said device when voltage across the output terminals is below said level, said second zener diode having a zener voltage such as to pass energizing current through said device when voltage across the output terminals is at said level.