US3603777A
Expired / Lapsed
US
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Method and apparatus for generating an electrical signal, representing a value of a function of an independent variable
Assignee: Jungner Instrument AB
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Filing: 1969-04-02
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Granted: 1971-09-07
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Expires: 1989-04-02
Abstract
Abstract A method of, and apparatus for, generating an electrical signal representing a value of a function of an independent variable. The method comprises the steps of generating an electrical signal, with a period T, representing the variations of the derivative df(x)/dx of the function f(x) within an interval xa x xb including the value x1, and deriving from said signal a pulseduration modulated signal consisting of pulses having a duration of AND A PULSE FREQUENCY OF 1/T, said pulses indicating the variations in the derivative df(x)/dx within the interval xa x x1, and deriving from said last-mentioned signal a DC voltage proportional to the mean value thereof and adding to this voltage a further DC voltage of a magnitude corresponding to any constant term, forming a part of the function f(x). Apparatus for carrying out the method is also disclosed.
Inventors
- 👤 Gunnar Axel Kihlberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:59
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/26; G06G7/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
138 words
A method of generating an electrical signal representing a value f(x1) of a function f(x) of an independent variable x, which corresponds to an arbitrary value x1 of said independent variable x, characterized by the following steps: generating an electrical signal with a period representing the variations in the derivative df(x)/dx of the function within an interval xa x xb including the value x1; deriving from said electrical signal a pulse-duration modulated signal consisting of pulses with a duration of and a frequency of 1/T, said pulses indicating the variations in the derivative df(x)/dx within the interval xa x x1; deriving from said pulse-duration modulated signal a DC voltage proportional to the mean valve thereof, and adding to this voltage a further DC voltage of a magnitude corresponding to any constant term forming part of the function f(x).
Claim 2
Independent Claim
138 words
A method of generating an electrical signal representing a value f(x1) of a function f(x) of an independent variable x, which corresponds to an arbitrary value x1 of said independent variable x, characterized by the following steps: generating an electrical signal with a period representing the variations in the derivative df(x)/dx of the function within an interval xa x xb including the value x1; deriving from said electrical signal a pulse-duration modulated signal consisting of pulses with a duration of and a frequency of 1/T, said pulses indicating the variations in the derivative df(x)/dx within the interval xa x x1; deriving from said pulse-duration modulated signal a DC voltage proportional to the mean valve thereof, and adding to this voltage a further DC voltage of a magnitude corresponding to any constant term forming part of the function f(x).
Claim 3
Dependent Claim
25 words
The method according to claim 1, characterized by building up the periodical electrical signal as a sum of Legendre-polynoms, or derivatives of such polynoms, respectively.
Claim 4
Dependent Claim
19 words
The method according to claim 1, characterized by building up the periodical electrical signal as a stepwise varying function.
Claim 5
Dependent Claim
17 words
The method according t claim 1, characterized by building up the periodical electrical signal from sinusoidal functions.
Claim 6
Dependent Claim
143 words
In an apparatus for generating an electrical signal representing a value f(x1) of a function f(x) of an independent variable x, which corresponds to an arbitrary value x1 of said independent variable x, the improvement comprising: generating means to generate a periodical electrical signal representative of the derivative of a certain function f(x) within a selected interval xa x xb; gate means to derive from said signal a periodical pulse-duration modulated signal representative of the derivative df(x)/dx within the interval xa x x1 where x1 xb; an averaging circuit emitting a DC voltage proportional to the mean value of the pulse-duration modulated signal; signal means providing a signal representative of a constant term forming a part of the function f(x); an adding circuit for adding said representative signal and said DC voltage and producing an output voltage proportional to said functional value f(x1).
Claim 7
Dependent Claim
143 words
In an apparatus for generating an electrical signal representing a value f(x1) of a function f(x) of an independent variable x, which corresponds to an arbitrary value x1 of said independent variable x, the improvement comprising: generating means to generate a periodical electrical signal representative of the derivative of a certain function f(x) within a selected interval xa x xb; gate means to derive from said signal a periodical pulse-duration modulated signal representative of the derivative df(x)/dx within the interval xa x x1 where x1 xb; an averaging circuit emitting a DC voltage proportional to the mean value of the pulse-duration modulated signal; signal means providing a signal representative of a constant term forming a part of the function f(x); an adding circuit for adding said representative signal and said DC voltage and producing an output voltage proportional to said functional value f(x1).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |