Dedicated avionics standby power supply
First Claim
1. For use in combination with an aircraft electrical supply and distribution system that includes a DC generator having at least a first DC output to normally provide a voltage V1, a first DC distribution system for said first DC output, a main rechargeable battery connected to said first DC distribution system, a second DC output to normally provide a voltage V2, a second DC distribution system for said second DC output, and a power failure signaling system for monitoring said second DC output and supplying a power failure indication at an output thereof when said second DC output commences to fall in level from said voltage V2, whereby a power failure indication is provided for an interval before said second DC output drops fully to zero in voltage level, a standby power supply for aircraft electronic apparatus, said aircraft electronic apparatus being normally supplied with DC electrical power at said voltage V2 over said second DC distribution system, said standby power supply having a principal input for connection to said first DC distribution system, said principal input comprising a first polarity input and second polarity input, and an output for connection to said aircraft electronic apparatus for supplying DC electrical power to said aircraft electronic apparatus when the DC voltage on said second DC electrical distribution system drops below voltage V2 in the course of failure of said DC generator, comprising:
- rechargeable battery means for storing electrical energy, said battery means having a first polarity output and a second polarity output, and said battery means having an output of voltage V3 between said first polarity output and said second polarity output, where said voltage V3 is less than said voltages V1 or V2;
a fast pulse mode battery charger;
said fast pulse mode battery charger having a charger input for receiving DC current, said charger input comprising a first polarity charger input and a second polarity charger input, and a charger output, said charger output connected to said rechargeable battery means for supplying DC charging current to said battery means responsive to DC current at said charger input;
DC to DC converter means;
said DC to DC converter means having first and second polarity inputs and an output for up-converting a DC voltage applied across said first and second polarity inputs to a second DC voltage at said output, said second DC voltage being of greater magnitude than said first DC voltage and said output of said DC to DC converter means providing said standby power supply output;
said DC to DC converter means output providing DC electrical power at said voltage V2 to said aircraft electronic apparatus, responsive to the application of said battery output voltage V3 across said DC to DC converter inputs;
first electromagnetic relay means;
said first electromagnetic relay means including an electromagnetic coil means and first and second make relay contacts, said make relay contacts being normally open condition to open an electrical circuit there through when said electromagnetic coil means is unenergized and, responsive to energization of said electromagnetic coil means, for closing an electrical circuit there through;
said first make relay contacts being connected in series with said first polarity charger input of said fast pulse mode battery charger and said first polarity input of said principal input, and said second make relay contacts being connected in series with said second polarity charger input of said fast pulse mode battery charger and said second polarity input of said principal input, wherein said fast pulse mode battery charger input is electrically isolated from said principal input when said electromagnetic coil means of said first electromagnetic relay means is unenergized, and wherein an electrical current conducting circuit between said principal input and said fast pulse mode battery charger input is completed only when said electromagnetic coil means of said first electromagnetic relay means is energized;
said electromagnetic coil means of said first electromagnetic relay means being connected to said second DC distribution system for receiving DC energization current, responsive to said DC generator supplying said voltage V2 to said second distribution system, whereby said first relay means completes a current path to said input of said fast pulse mode battery charger when said DC generator is functioning, and interrupts said current path when said DC generator is not functioning;
second electromagnetic relay means;
said second electromagnetic relay means including electromagnetic coil means and first and second break relay contacts, said break relay contacts thereof being normally closed to complete an electrical circuit therethrough when said electromagnetic coil means thereof is unenergized and, responsive to energization of said electromagnetic coil means thereof, for opening said electrical circuit therethrough;
said first break relay contacts being connected in series between said first polarity output of said rechargeable battery means and said first polarity input of said DC to DC converter means; and
said second break relay contacts being connected in series between said second polarity input of said DC to DC converter means and said second polarity output of said rechargeable battery means;
wherein said rechargeable battery means output is connected to said DC to DC converter means to supply current to said DC to DC converter means only when said electromagnetic coil means of said second electromagnetic relay means is de-energized and wherein said rechargeable battery means output is disconnected from said DC to DC converter means when said electromagnetic coil means of said second electromagnetic relay means is energized;
semiconductor switch means;
said semiconductor switch means having a control input and first and second output terminals for normally providing a current conducting path between said first and second output terminals during the absence of a power failure indication voltage at said control input;
said control input of said semiconductor switch means being connected to said power failure indication system output for receiving a power failure indication voltage when said DC generator is failing;
said electrical coil means of said second electromagnetic relay means being connected electrically in series with said first and second output terminals of said semiconductor switch means across said second DC distribution system, wherein said second DC distribution system provides energization current to said electromagnetic coil means of said second electromagnetic relay means in the absence of a power failure indication voltage at said control input of said semiconductor switch means, whereby said second electromagnetic relay means prevents energization of said DC to DC converter means, and said standby power supply cannot supply DC current to said electronic apparatus when said DC generator is functioning;
said semiconductor switch means being operable to switch into the electrically non-conducting state to discontinue energization of said second relay'"'"'s electromagnetic coil means;
whereby, in the event said DC generator fails, said electromagnetic coil means of said second electromagnetic relay means deenergizes and said second electromagnetic relay mean'"'"'s break relay contacts complete a current conducting circuit from said rechargeable battery means to said DC to DC converter means prior to deenergization of said electromagnetic coil of said first electromagnetic relay means; and
said fast pulse mode battery charger is interrupted to discontinue charging of said rechargeable battery means upon deenergization of said first electromagnetic relay means.
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Accused Products
Abstract
A standby power supply dedicated to a peripheral electronics apparatus on aircraft provides an isolated ungrounded self-contained source of DC operating voltage. That source is applied to the electronics apparatus upon indication of turbine generator shut-down or failure before the voltage generated by the turbine generator completely falls off. Formed with an EMI filter, a fast pulse mode battery charger, a lead-acid battery pack, a DC to DC converter, and a pair of electromagnetic relays, the standby power supply ensures that the electronic apparatus is never without operating power even momentarily.
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Citations
9 Claims
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1. For use in combination with an aircraft electrical supply and distribution system that includes a DC generator having at least a first DC output to normally provide a voltage V1, a first DC distribution system for said first DC output, a main rechargeable battery connected to said first DC distribution system, a second DC output to normally provide a voltage V2, a second DC distribution system for said second DC output, and a power failure signaling system for monitoring said second DC output and supplying a power failure indication at an output thereof when said second DC output commences to fall in level from said voltage V2, whereby a power failure indication is provided for an interval before said second DC output drops fully to zero in voltage level, a standby power supply for aircraft electronic apparatus, said aircraft electronic apparatus being normally supplied with DC electrical power at said voltage V2 over said second DC distribution system, said standby power supply having a principal input for connection to said first DC distribution system, said principal input comprising a first polarity input and second polarity input, and an output for connection to said aircraft electronic apparatus for supplying DC electrical power to said aircraft electronic apparatus when the DC voltage on said second DC electrical distribution system drops below voltage V2 in the course of failure of said DC generator, comprising:
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rechargeable battery means for storing electrical energy, said battery means having a first polarity output and a second polarity output, and said battery means having an output of voltage V3 between said first polarity output and said second polarity output, where said voltage V3 is less than said voltages V1 or V2; a fast pulse mode battery charger; said fast pulse mode battery charger having a charger input for receiving DC current, said charger input comprising a first polarity charger input and a second polarity charger input, and a charger output, said charger output connected to said rechargeable battery means for supplying DC charging current to said battery means responsive to DC current at said charger input; DC to DC converter means; said DC to DC converter means having first and second polarity inputs and an output for up-converting a DC voltage applied across said first and second polarity inputs to a second DC voltage at said output, said second DC voltage being of greater magnitude than said first DC voltage and said output of said DC to DC converter means providing said standby power supply output;
said DC to DC converter means output providing DC electrical power at said voltage V2 to said aircraft electronic apparatus, responsive to the application of said battery output voltage V3 across said DC to DC converter inputs;first electromagnetic relay means; said first electromagnetic relay means including an electromagnetic coil means and first and second make relay contacts, said make relay contacts being normally open condition to open an electrical circuit there through when said electromagnetic coil means is unenergized and, responsive to energization of said electromagnetic coil means, for closing an electrical circuit there through; said first make relay contacts being connected in series with said first polarity charger input of said fast pulse mode battery charger and said first polarity input of said principal input, and said second make relay contacts being connected in series with said second polarity charger input of said fast pulse mode battery charger and said second polarity input of said principal input, wherein said fast pulse mode battery charger input is electrically isolated from said principal input when said electromagnetic coil means of said first electromagnetic relay means is unenergized, and wherein an electrical current conducting circuit between said principal input and said fast pulse mode battery charger input is completed only when said electromagnetic coil means of said first electromagnetic relay means is energized; said electromagnetic coil means of said first electromagnetic relay means being connected to said second DC distribution system for receiving DC energization current, responsive to said DC generator supplying said voltage V2 to said second distribution system, whereby said first relay means completes a current path to said input of said fast pulse mode battery charger when said DC generator is functioning, and interrupts said current path when said DC generator is not functioning; second electromagnetic relay means; said second electromagnetic relay means including electromagnetic coil means and first and second break relay contacts, said break relay contacts thereof being normally closed to complete an electrical circuit therethrough when said electromagnetic coil means thereof is unenergized and, responsive to energization of said electromagnetic coil means thereof, for opening said electrical circuit therethrough; said first break relay contacts being connected in series between said first polarity output of said rechargeable battery means and said first polarity input of said DC to DC converter means; and
said second break relay contacts being connected in series between said second polarity input of said DC to DC converter means and said second polarity output of said rechargeable battery means;
wherein said rechargeable battery means output is connected to said DC to DC converter means to supply current to said DC to DC converter means only when said electromagnetic coil means of said second electromagnetic relay means is de-energized and wherein said rechargeable battery means output is disconnected from said DC to DC converter means when said electromagnetic coil means of said second electromagnetic relay means is energized;semiconductor switch means;
said semiconductor switch means having a control input and first and second output terminals for normally providing a current conducting path between said first and second output terminals during the absence of a power failure indication voltage at said control input;said control input of said semiconductor switch means being connected to said power failure indication system output for receiving a power failure indication voltage when said DC generator is failing; said electrical coil means of said second electromagnetic relay means being connected electrically in series with said first and second output terminals of said semiconductor switch means across said second DC distribution system, wherein said second DC distribution system provides energization current to said electromagnetic coil means of said second electromagnetic relay means in the absence of a power failure indication voltage at said control input of said semiconductor switch means, whereby said second electromagnetic relay means prevents energization of said DC to DC converter means, and said standby power supply cannot supply DC current to said electronic apparatus when said DC generator is functioning; said semiconductor switch means being operable to switch into the electrically non-conducting state to discontinue energization of said second relay'"'"'s electromagnetic coil means; whereby, in the event said DC generator fails, said electromagnetic coil means of said second electromagnetic relay means deenergizes and said second electromagnetic relay mean'"'"'s break relay contacts complete a current conducting circuit from said rechargeable battery means to said DC to DC converter means prior to deenergization of said electromagnetic coil of said first electromagnetic relay means; and
said fast pulse mode battery charger is interrupted to discontinue charging of said rechargeable battery means upon deenergization of said first electromagnetic relay means. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A standby power supply for electronic apparatus, said electronic apparatus normally being supplied with electrical power by an engine driven DC generators comprising:
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first switching means having a first and second state, said first switching means being placed in said first state, responsive to said DC generator generating DC power, and switchable to said second state, responsive to failure of said DC generator; second switching means having a first and second state, said second switching means being placed in said first state, responsive said DC generator generating power, and switchable to said second state, responsive to failure of said DC generator; rechargeable battery means; battery charger means;
said battery charger means having an input for receiving DC power from said DC generator and having an output connected to said rechargeable battery means for applying DC charging current to said rechargeable battery means responsive to said first switching means being in said first state;means for supplying current from said rechargeable battery means to said electronic apparatus responsive to said second switching means being in said second state; said first switching means being switchable from said first state to said second state in a predetermined period of time, T1, responsive to failure of said DC generator; said second switching means being switchable from said first state to said second state in a predetermined period of time, T2, responsive to failure of said DC generator; and
wherein said period of time T1>
T2;
whereby application of DC current from said rechargeable battery means to said electronic apparatus overlaps in time application of DC current to said battery means from said battery charger means by a short interval, T1=T2, to ensure continuity of DC current to said electronic apparatus.
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9. A dedicated standby power supply for an aircraft electronic apparatus, said aircraft electronic apparatus being normally served with DC power from an aircraft power generator over an aircraft electrical distribution system containing a first line normally at a first voltage relative to ground potential, and a second line normally at a second voltage relative to ground potential, said second voltage being of lower level than said first voltage, and further containing a third line for normally providing a power on indication responsive to presence of said second voltage on said second line and alternately providing a power failure indication responsive to a predetermined falloff in level of said second voltage on said second line from a first level to a second lower level, indicative of failure of said aircraft power generator;
- said second lower level being greater than zero volts, comprising;
first relay means, said first relay means having an electromagnetic coil connected to said second line for receiving energizing current therefrom; second relay means, said second relay means having an electromagnetic coil connected to said second line for receiving energizing current therefrom; semiconductor switch means having a control input and first and second output terminals; means for connecting said control input to said third line; and
means for connecting said electromagnetic coil of said second relay means and said output terminals of said semiconductor switch means in series circuit with said second line;said semiconductor switch means normally providing a current conducting path between said first and second output terminals thereof during the presence of said power on indication, whereby said electromagnetic coil of second relay means receives energizing current from said second line; rechargeable battery means; battery charger means; said battery charger means having an input and an output; said battery charger means output being connected to said rechargable battery means for supplying charging current to said rechargeable battery means, responsive to said battery charger means receiving DC current from said first line; said first relay means including make contact means for connecting said first line to said battery charger means input responsive to energization of said electromagnetic coil of said first relay means; DC-to-DC converter means, having an input and an output, for converting DC applied at said input to ungrounded DC voltage at said output; said second relay means for connecting said rechargeable battery means to said input of said DC-to-DC converter means, responsive to said semiconductor switch means being in an electrically non-conductive state, wherein said electromagnetic coil of said second relay means no longer receives energizing current; wherein, responsive to appearance of a power failure indication at said third line, said second relay means connects said DC-to-DC converter means input to said rechargeable battery means prior to said voltage at said first and second lines decreasing to ground potential and the de-energization of said electromagnetic coil of said first relay means;
whereby said DC-to-DC converter means supplies ungrounded voltage to said aircraft electronic apparatus before said aircraft power generator completely ceases to supply DC power to said aircraft electrical distribution system.
- said second lower level being greater than zero volts, comprising;
Specification