Random voltage source with substantially uniform distribution

• US 4,578,649 A
• Filed: 02/04/1985
• Issued: 03/25/1986
• Est. Priority Date: 02/04/1985
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Shupe, Chester D.
• Primary Examiner(s): LaRoche, Eugene
• Assistant Examiner(s): Wan, G.
• Application Number:
  US06/697,991
• Time in Patent Office: 414 Days
• Field of Search: 331/78, 331/149, 364/716, 364/717
• US Class Current: 331/78
• CPC Class Codes: H03B 29/00 Generation of noise currents and voltages gasfilled discharge tubes with solid cathode specially adapted as noise generators H01J17/005

Abstract

A Gaussian noise generator having a sample and hold circuit connected to the output thereof for providing random voltage samples, a voltage controlled oscillator controlled by the random voltage samples and providing a linear 10 sawtooth output having a frequency dependent upon the amplitude of the random voltage samples, and a second sample and hold circuit connected to the oscillator to provide random voltage output samples with substantially uniform distribution between predetermined limits.

Claims

1. A random voltage source with substantially uniform distribution comprising:

a Gaussian noise generator providing an output;

a first sample and hold circuit connected to receive the output from said Gaussian noise generator and provide random voltage samples at an output thereof;

a voltage controlled oscillator having a control input and an output and providing a substantially sawtooth shaped signal at the output with a frequency dependent upon the voltage applied to the control input, the control input being connected to receive the random voltage samples from said first sample and hold circuit; and

a second sample and hold circuit connected to the output of said voltage controlled oscillator and providing a random voltage output.

2. A random voltage source with substantially uniform distribution as claimed in claim 1 wherein the first and second sample and hold circuits are both controlled by the same source of timing pulses.

3. A random voltage source with substantially uniform distribution as claimed in claim 2 including delay means connected to receive the random voltage output from said second sample and hold circuit and provide timing pulses at an output, which timing pulses are connected to control both sample and hold circuits.

4. A random voltage source with substantially uniform distribution as claimed in claim 1 wherein the voltage controlled oscillator is a substantially linear sawtooth voltage controlled oscillator.

5. A random voltage source with substantially uniform distribution as claimed in claim 1 wherein said voltage controlled oscillator is constructed so that the application of a voltage sample of highest probability to the control input of said voltage controlled oscillator produces approximately the center frequency of said voltage controlled oscillator.

6. A random voltage source with substantially uniform distribution as claimed in claim 5 including in addition a source of timing pulses connected to control both said first and said second sample and hold circuits substantially together and with a frequency much less than the frequency of said voltage controlled oscillator.

7. A random voltage source with substantially uniform distribution comprising:

a Gaussian noise generator providing random noise generally in accordance with Gaussian distribution probability at an output thereof;

a first sample and hold circuit having a control input, a signal input connected to the output of said Gaussian noise generator and an output, said first sample and hold circuit being connected to provide random voltage samples at the output thereof in response to timing signals applied to the control input thereof;

a linear sawtooth voltage controlled oscillator having a control input connected to the output of said first sample and hold circuit and an output, the output having sawtooth signals thereon with a frequency dependent upon the amplitude of the random voltage samples applied to the control input;

a second sample and hold circuit having a control input, a signal input connected to the output of said voltage controlled oscillator, and an output, said second sample and hold circuit being connected to provide random voltage samples at the output thereof, the random voltage samples being distributed substantially uniformly between a pair of limits; and

timing signal generating means, having an output connected to the control inputs of said first and second sample and hold circuits, for providing timing signals the spacing of which determines the pair of limits.

8. A random voltage source with substantially uniform distribution as claimed in claim 7 wherein the timing signal generating means is constructed to provide timing signals spaced apart a distance greater than approximately the length of a single sawtooth waveform at the center frequency of said voltage controlled oscillator.

9. A random voltage source with substantially uniform distribution as claimed in claim 8 wherein the voltage controlled oscillator is constructed so that the application of a voltage sample of highest probability to the control input of said voltage controlled oscillator produces approximately the center frequency of said voltage controlled oscillator.

10. A method of producing random voltage samples with substantially uniform distribution comprising the steps of:

providing a Gaussian noise signal;

sampling the Gaussian noise signal at predetermined intervals to provide voltage samples having random amplitudes with Gaussian distribution;

providing a sawtooth shaped signal in response to the voltage samples, said sawtooth shaped signal having a frequency dependent upon the amplitude of the voltage samples; and

sampling the sawtooth shaped signals at the predetermined intervals to produce random voltage samples with substantially uniform distribution.

11. A method as claimed in claim 10 wherein an approximately center frequency sawtooth shaped signal is produced in response to a voltage sample of highest probability in the Gaussian noise signal.

12. A method as claimed in claim 11 wherein the predetermined interval of the sampling steps is approximately greater in duration than a single sawtooth wave form at the center frequency.

13. A method as claimed in claim 10 wherein the sawtooth shaped signal provided is linear.

14. A method as claimed in claim 10 including the step of delaying the voltage samples with substantially uniform distribution and utilizing the delayed samples to time the two sampling steps.