Programmable supervisory circuit and applications therefore

• US 6,104,968 A
• Filed: 12/24/1996
• Issued: 08/15/2000
• Est. Priority Date: 12/28/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Ananth, Ravi S.
• Primary Examiner(s): Gordon, Paul P.
• Application Number:
  US08/773,020
• Time in Patent Office: 1,330 Days
• Field of Search: 700/6, 700/9, 700/10, 700/73, 700/74, 700/79, 700/80, 700/81, 700/82, 700/297, 700/298, 702/60, 702/61, 702/62, 702/179, 702/180, 702/181, 702/189, 702/198, 702/199, 702/57, 702/64, 324/142, 323/283, 323/285
• US Class Current: 700/297
• CPC Class Codes: G01R 19/003 Measuring mean values of current or voltage during a given time interval
• CPC Class Codes: G01R 19/02 Measuring effective values, i.e. root-mean-square values
• CPC Class Codes: G01R 19/2506 Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values G01R19/003 takes precedence; Details concerning sampling, digitizing or waveform capturing displaying waveforms G01R13/00; analog sampling G01R19/0053
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: G06F 7/602 using delta-sigma sequences

Abstract

The invention herein provides a supervisory circuit which is adapted to monitor an input signal and produce as an output signal, a parametric signal corresponding to the input signal. The circuit includes an input for receiving the input signal, and a stochastic processor coupled to the input for receiving the input signal and processing it to derive a signal that represents a parametric measure of the input signal. An output connected to said stochastic processor provides the parametric output signal as an output for supervisory purposes.

Claims

1. A supervisory circuit for deriving a parametric output of an input signal comprising:

a) input means for receiving said input signal;

b) mean square processor for determining the mean square value of the input of said input signal;

c) conversion processor for converting said mean square value into a random pulse density modulated bitstream representative of said mean square value;

d) stochastic processor for converting said random pulse density modulated bitstream into a stochastic representation of the RMS value of the input signal;

e) output means for outputting said stochastic representation of said RMS value.

2. A supervisory circuit for deriving a parametric output signal of an analog input signal comprising:

a) input circuit including a delta-sigma analog to digital converter adapted to produce a serial pulse density modulated bit stream representation of said analog input signal;

b) a running averager processor adapted to process said bit stream representation of said analog input signal to produce a representation of the running average of said bitstream;

c) a multi bit modulated squarer processor adapted to calculate the square of said running average and integrate said square over a suitable time period to derive a parallel binary representation of the mean square value of said analog input signal;

d) a randomizer adapted to convert said binary representation of the mean square value of the analog input signal to a serial random pulse density modulated bitstream;

e) a stochastic square root processor adapted to process said random pulse density modulated bitstream to produce a parametric signal corresponding to the root mean square value of said analog input signal;

f) output means to output said root mean square value signal.

3. The supervisory circuit of claim 2 wherein said stochastic square root processor is adapted to accept said serial random pulse density modulated bitstream as input and uses as negative feedback the stochastic square of the output of said stochastic processor to produce an output corresponding to the root mean square value of said analog input signal.

4. The supervisory circuit of claim 2 wherein:

said running averager processor is adapted to process said bit stream representation of said analog input signal to produce a parallel representation of the running average of said bitstream;

said multi bit modulated squarer processor is adapted to calculate the square of said running average by modulating said average by said serial pulse density modulated bitstream representation of said analog input signal to obtain a multi bit representation of said analog input signal squared, and integrate said square over the period of said input signal or a suitable time period to derive a parallel binary representation of the mean square value of said analog input signal; and

,

wherein said stochastic square root processor comprises;

a) an up down counter having incrementing and decrementing inputs, and an output, and being adapted to receive said random pulse density modulated bitstream at said incrementing input, the output signal of said counter being converted by a randomizer to an output random pulse density modulated bitstream,

b) a feedback circuit, said output bitstream being further modified by said feedback circuit to provide a decrementing input to said counter, said feedback circuit comprising;

a) a decorrelator to decorrelate said output bitstream; and

,

b) means to feed back the boolean product of said output bitstream and said decorrelated bitstream (obtaining a squared representation of output value of the counter) to said decrementing input of said counter,

said output signal of said counter representing the square root of said mean square input, thereby producing a parametric signal which corresponds to the root mean square value of the analog input signal.

5. The supervisory circuit of claim 4 wherein said stochastic square root circuit is adapted to produce

a) parallel output, and

b) a serial output utilizing said randomizer to derive said serial output.

6. A supervisory circuit which is adapted to monitor an input signal including an analog voltage and produce as an output, a parametric signal corresponding to said input signal, said circuit comprising:

a delta-sigma analog-to-digital converter for receiving said input signal;

stochastic processing circuitries including circuit arrangement for obtaining a mean square value signal of the input signal and a stochastic computation circuit, responsive to said mean square value signal, to provide a stochastic representation of the RMS voltage of the input signal, operatively coupled to said converter for receiving said input signal and stochastically processing said signal to derive a signal that represents a parametric measure of said input signal; and

output means connected to said stochastic processor to output said parametric output signal which is proportional to the RMS value of the input signal.

7. A supervisory circuit which is adapted to monitor an input signal and produce as an output, a parametric signal corresponding to said input signal, said circuit comprising:

a delta-sigma analog-to-digital converter for receiving said input signal;

a stochastic processor coupled to said converter for receiving said input signal and stochastically processing said signal to derive a signal that represents a parametric measure of said input signal;

output means connected to said stochastic processor to output said parametric output signal; and

a PROM adapted to response to a signal derived by the stochastic processor of said supervisory circuit to produce a threshold status output when said signal is within a preselected range of values.

8. The supervisory circuit of claim 7 wherein said PROM is adapted to respond to said root mean square value output of said supervisory circuit.

9. The supervisory circuit of claim 8 wherein said PROM is adapted to respond to said root mean square value output of said supervisory circuit.

10. A supervisory circuit which is adapted to monitor an input signal and produce as an output, a parametric signal corresponding to said input signal, said circuit comprising:

a delta-sigma analog-to-digital converter for receiving said input signal;

a stochastic processor coupled to said converter for receiving said input signal and stochastically processing said signal to derive a signal that represents a parametric measure of said input signal that is made available externally; and

output means connected to said stochastic processor to output said parametric output signal.

11. A supervisory circuit which is adapted to monitor an input signal and produce as an output, a parametric signal corresponding to said input signal, said circuit comprising:

a delta-sigma analog-to-digital converter for receiving said input signal;

stochastic processing circuitries including a running average circuit, a multi-bit modulated squarer circuit coupled to the running averager circuit, and a stochastic computation circuit coupled to the squarer circuit operatively coupled to said converter for receiving said input signal and stochastically processing said signal to derive a signal that represents a parametric measure of said input signal; and

output means connected to said stochastic processor to output said parametric output signal.

12. The supervisory circuit of claim 11 further including a radomizer circuit coupled to the stochastic computation circuit.

13. The supervisory circuit of claim 11 further including a sequence controller coupled to the stochastic computation circuit and the modulated squarer circuit.

14. A supervisory circuit which is adapted to monitor an input signal and produce as an output, a parametric signal corresponding to said input signal, said circuit comprising:

a delta-sigma analog-to-digital converter for receiving said input signal;

stochastic processing circuitries including a circuit arrangement for obtaining a mean square value signal of the input signal and a stochastic computation circuit, responsive to said mean square value signal, to provide a stochastic representation of the RMS voltage of the input signal, operatively coupled to said converter for receiving said input signal and stochastically processing said signal to derive a signal that represents a parametric measure of said input signal; and

output means connected to said stochastic processor to output said parametric output signal.

15. A power supply comprising:

a power convertor for converting an input into a regulated output, and a supervisory circuit for controlling said power convertor;

said power convertor being governed by said supervisory circuit, said supervisory circuit providing at least one output control signal to said power converter wherein said at least one output control signal is derived from stochastic processing of an input signal corresponding to the input to said power supply wherein said stochastic processing is performed by stochastic processing circuitries including, a circuit arrangement for obtaining a mean square value signal of the input signal and a stochastic computation circuit, responsive to said mean square value signal, to provide a stochastic representation of the RMS voltage of the input signal, concatenated within said supervisory circuit.