Self-diagnostic redundant modular power supply

• US 4,528,458 A
• Filed: 01/06/1984
• Issued: 07/09/1985
• Est. Priority Date: 01/06/1984
• Status: Expired due to Fees

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Nelson, Hilding E., Nesdahl, Myron A., Gallati, Marvin L.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Jennings, Derek S.
• Application Number:
  US06/568,968
• Time in Patent Office: 550 Days
• Field of Search: 307/44, 307/64, 307/66, 307/80, 324/51, 340/516, 340/635, 340/653, 340/825.16, 340/825.17
• US Class Current: 307/64
• CPC Class Codes: H02J 1/10 Parallel operation of dc sources

Abstract

A redundant modular power supply having a plurality of modules including a redundant module is disclosed which includes an apparatus for testing for a fault in any of the modules of the power supply. The redundant module is provided with a margin terminal, which when receiving a command from the testing apparatus, causes the redundant module to output current. The testing apparatus periodically issues such commands to the redundant module, monitors the output of the redundant module, and indicates an error condition if the redundant module does not respond properly to the commands from the testing apparatus. If the redundant module outputs current when not commanded to do so, a failure of one of the other modules in the power supply is indicated. If the redundant module fails to output current when commanded to do so, a failure of the redundant module is indicated.

Claims

1. A modular power supply comprising at least one worker module for supplying power requirements;

a redundant module in parallel with said worker module, said redundant module including current delivery means responsive to a test command for causing said redundant module to deliver current, and output signaling means for generating an electrical signal when current is being output from said redundant module; and

power supply testing means including test signal generating means operatively connected to said redundant module for generating a test command thereby causing said redundant module to deliver current, and indicating means operatively connected to said output signaling means and being operable for indicating the output of current from said redundant module other than when said current-output is responsive to a test command generated by said test command generating means.

2. The modular power supply of claim 1 wherein said indicating means includes means operable for indicating the lack of output current from said redundant module when said redundant module has been ordered to deliver current by a test command generated by said power supply testing means.

3. The modular power supply of claim 1 wherein said worker module includes means for limiting its current output to a set level, and said modular power supply further comprising:

a controlling module connected in parallel with said worker module for supplying a portion of the power requirements, said controlling module including a power output terminal for outputting regulated power;

adjustable voltage sensing means for adjustably sensing the voltage on said power output terminal; and

current output means operatively connected to said voltage sensing means for varying the current output of said controlling module responsive to the adjustment of said voltage sensing means whereby the voltage level on said power output terminal is controlled.

4. The modular power supply of claim 1 comprising a plurality of worker modules, including the previously mentioned worker module, arranged in decks for supplying a plurality of separate supply voltages;

a plurality of redundant modules, including the previously mentioned redundant power supply module, wherein one of said redundant power supply modules is connected in parallel with at least one of said worker power supply modules in each of said decks; and

wherein said power supply testing means includes selecting means for sequentially selecting voltage supply decks for testing, and a plurality of said indicating means, each of said indicating means being operatively connected to one of the respective redundant power supply modules of said voltage supply decks.

5. The modular power supply of claim 4 wherein said power supply testing means comprises:

counting means having means for generating less significant bits and a most significant bit, said less significant bits counting from one to a number representative of the number of decks in said power supply, and said most significant bit alternating between a first state and a second state, said most significant bit changing to its other state subsequent to each occurrence of said counting means less significant bits counting to the number of decks; and

addressable means responsive to said less significant bits and said most significant bit for testing a different deck with each number representation of said less significant bits.

6. The modular power supply of claim 5 wherein said addressable means further includes means for testing the worker modules of said decks when said most significant bit is in said first state, and for testing the redundant module of said decks when said most significant bit is in said second state.

7. A testing circuit for testing the modules of a voltage deck in a redundant modular power supply having worker modules and a redundant module, said testing circuit comprising:

counting means for sequentially conducting a worker module test and a redundant module test;

output means responsive to said counting means and having an output terminal for connection to the redundant module, said output means placing a command on said output terminal instructing the redundant module to output current during said redundant module test;

input means having an input terminal for receiving a signal from said power supply indicating the output of said power supply; and

fault determining means responsive to said counting means and said input means for determining a fault in said redundant power supply dependent upon the instruction on said output terminal and the signal on said input terminal.

8. The testing circuit of claim 7 comprising a visual indicating means responsive to said fault determining means for providing a visual indication of a detected fault.

9. The testing circuit of claim 7 comprising a plurality of output means, input means and faults determining means arranged for determining faults on a plurality of voltage decks in said redundant modular power supply.

10. The testing circuit of claim 9 further comprising a plurality of visual indicators, one of said visual indicators being responsive to each of said fault determining means for giving a visual indication of a detected fault in its respective voltage deck.

11. In a redundant modular power supply having a plurality of worker modules organized in separate voltage decks, and a plurality of redundant modules, one for each voltage deck, the method of:

a. providing each redundant module with an input terminal which, when addressed, causes its redundant module to output current;

b. providing each redundant module with an output terminal which outputs an electrical signal when its redundant module is outputting current;

c. sequentially addressing each redundant module thereby causing the addressed redundant module to output current;

d. monitoring the output terminal of the addressed redundant module; and

e. providing an indication of any addressed redundant module which does not output an electrical signal indicative of outputting current when the respective redundant module is addressed.

12. The method of claim 11 further comprising:

f. sequentially monitoring the output terminal of each redundant module; and

g. providing an indication of any redundant module outputting an electrical signal indicative of outputting current when the respective redundant module has not been ordered to do so.

13. The method of claim 11 further comprising:

f'"'"'. replacing the respective redundant module indicated in step e.

14. The method of claim 12 further comprising:

h. replacing one of the worker modules in the voltage deck of the respective redundant module indicated in step g.

15. In a power supply having a plurality of modules separably addable to a voltage bus, each of said modules having a voltage indicator for indicating if its voltage output is at an adjustable voltage indicating level and a current indicator for indicating if it is outputting current, the method comprising:

a. adding a number of modules to the bus sufficient to meet the power demands of the bus;

b. adjusting the voltage level of one of the modules until its voltage indicator indicates that its output is at a desired voltage level;

c. adjusting the rest of the levels of the other modules until their voltage indicators indicate that their output voltages are just below the levels so adjusted;

d. removing the other modules one at a time until the current indicators of all of the modules indicate that all of the modules are outputting current;

e. adding one more module and adjusting its voltage indicating level until its voltage indicator indicates that its voltage output as at the desired voltage level; and

f. periodically testing the current indicator of said last added module for an indication of current being output.

16. The method of claim 15 further comprising:

g. periodically commanding said last added module to output current; and

h. testing the current indicator of said last added module to determine if current is being output in response to the command of step g.

17. An apparatus for testing a power supply comprising:

an oscillator having an output, said oscillator generating a series of pulses;

a counter connected to the output of said oscillator and having a most significant bit terminal, said counter operable for counting the pulses of said oscillator and changing the state of said most significant bit terminal between a first state and a second state dependent upon the number of pulses counted by said counter;

a gate having an input connected to the most significant bit terminal of said counter, and an output whose state is changeable between a first state and a second state dependent upon the state of the most significant bit on the input of said gate;

an apparatus input terminal for connection to the power supply being tested, said state of said apparatus input terminal being changeable between a first state and a second state dependent upon the output of a power supply being tested;

a first flip-flop operatively connected to said apparatus input terminal and said most significant bit terminal, said first flip-flop having an output terminal whose state is changeable between a first state and a second state dependent upon the state of said apparatus input terminal and said most significant bit terminal; and

a second flip-flop operatively connected to said apparatus input terminal and said most significant bit terminal, said second flip-flop having an output terminal whose state is changeable between a first state and a second state dependent upon the state of said apparatus input terminal and said most significant bit terminal;

wherein the states of the output terminals of said first flip-flop and second flip-flop indicates the functional condition of a power supply being tested.

18. The apparatus of claim 17 further comprising a visual indicator connected to the outputs of said first flip-flop and said second flip-flop for giving a visual indication when the output of either of said first flip-flop or said second flip-flop changes from its first state to its second state.