Battery discharge indicator and control circuit

Claim 2

A battery discharge indicator comprising a pair of terminals adapted to be connected across the terminals of a battery under supervision, indicating means connected in series with a solid state switching element across said terminals, circuit means including voltage-regulating means connected to said switching element and responsive to the difference between the voltage across said terminals and the voltage across said voltageregulating means to activate said switching element to energize said indicating means when the voltage across said terminals decreases to a predetermined value relative to the voltage across said voltage-regulating means, timing means connected to said switching element to initiate a timing cycle upon the energization of said indicating means, switching means connected to said timing means to perform a control function at the end of said timing cycle, said switching means including a controlled rectifier having an anode, a cathode and a control element means operatively connected to the anode of said controlled rectifier for rendering said controlled rectifier nonconductive at the end of said timing cycle, and second circuit means connected to said solid state switching element to deenergize it to cause said indicating means to be alternately energized and deenergized as the voltage of said battery decreases to said predetermined value.

Claim 3

A battery discharge indicator and control means for an industrial material handling truck comprising, in combination, a pair of terminals adapted to be connected across the battery supplying power to said truck, indicating means connected in series with a solid-state switching element across said terminals, circuit means including voltage regulating means connected to said switching element and responsive to the difference between the voltage across said terminals and the voltage across said voltage-regulating means to activate said switching element to energize said indicating means when the voltage across said terminals decreases to a predetermined value relative to said voltage-regulating means, second circuit means connected to said switching element to periodically deactivate said switching element and deenergize said indicating means to cause said indicating means to be periodically energized when the voltage across said terminals decreases to said predetermined value, timing means connected to said switching element and periodically energized when the voltage across said terminals decreases to said predetermined value, the periodic energization of said timing means providing a timing cycle and switching means including a controlled rectifier operatively connected to said timing means, said controlled rectifier being arranged so as to be deenergized by said timing means at the end of said timing cycle, the deenergization of said controlled rectifier preventing said truck from performing any material handling operation until said terminals are disconnected from said battery.

Claim 4

A battery discharge indicator and control means for an industrial material handling truck comprising, in combination, a pair of terminals adapted to be connected across the battery supplying power to said truck, indicating means connected in series with a solid-state switching element across said terminals, circuit means including voltage regulating means connected to said switching element and responsive to the difference between the voltage across said terminals and the voltage across said voltage-regulating means to activate said switching element to energize said indicating means when the voltage across said terminals decreases to a predetermined value relative to said voltage-regulating means, second circuit means connected to said switching element to periodically deactivate said switching element and deenergize said indicating means to cause said indicating means to be periodically energized when the voltage across said terminals decreases to said predetermined value, timing means connected to said switching element and periodically energized when the voltage across said terminals decreases to said predetermined value, the periodic energization of said timing means providing a timing cycle and switching means including a controlled rectifier operatively connected to said timing means, said controlled rectifier being arranged so as to be deenergized by said timing means at the end of said timing cycle, the deenergization of said controlled rectifier preventing said truck from performing any material handling operation until said terminals are disconnected from said battery.

Claim 5

Apparatus as specified in claim 2 wherein said timing means comprises a capacitor fired unijunction transistor which is charged in pulses to the firing voltage of the transistor.

Claim 6

Apparatus as defined in claim 2 wherein said industrial material-handling truck includes a hydraulic pump direct current motor, a relay having a normally open contact and an operating coil, said motor and said contact being connected in series across said battery, said controlled rectifier having An anode-cathode circuit and a control element, said anode-cathode circuit being connected in series with said operating coil across said battery, said anode-cathode circuit of said controlled rectifier normally open contact is held closed thereby supplying operating current to said motor, and means operatively connected to the anode of said controlled rectifier for rendering said controlled rectifier nonconductive at the end of said timing cycle whereby current will terminate in said anode-cathode circuit effecting opening of said contact and thus, disconnecting said motor from said battery.