EP0072144A2
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EP
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A-D converter for use in an electronic balance
Assignee: Shimadzu Corp
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Filing: 1982-07-27
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Granted: —
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Expires: 2002-07-27
Abstract
Abstract The analogue signal is fed to converting unit 1 of small capacity but high resolution. When the input signal exceeds the capacity of unit 1 an over-signal is supplied to a digital memory 3 which, by way of a D-A conversion unit 5 and an analogue subtractor 6, subtends from the input signal an integral muitiple of the output of unit 1. The corresponding digital amount is added to the output of unit 1 by the adder 4. When the input to converter 1 is within its capacity, an under-signal is fed to memory 3 and determines the extent of the subtraction.
Inventors
- 👤 Akira Komoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 12:03
CPC Classifications
G; G01; G01G; G01G23/00; G01G23/18; G01G23/36; G01G23/37; G01G23/3707; G01G23/3714; H; H03; H03M; H03M1/00; H03M1/06; H03M1/12; H03M1/48; H03M1/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
178 words
An A-D converter for use in an electronic balance, comprising: a pulse-modulating D-A converting unit which converts an input digital signal to an analog output signal; an analog subtracter which subtracts said analog output signal of said pulse-modulating D-A converting unit from the analog signal to be.measured; an A-D converting unit which converts the output of said analog subtracter to a digital signal, generates an oversignal when an input signal inputted thereto overflows the same and generates an undersignal when said input signal inputted thereto falls down to zero; a digital memory which can store a digital signal corresponding to an integral multiple of the saturated output level of said A-D converting unit, the number of multiplication being equal to the difference made by subtracting the number of said undersignal from that of said oversignal; a digital adder which adds the contents stored in said digital memory to the digital output of said A-D converting unit; a leading means for leading the contents stored in said digital memory to the input terminals of said pulse-modulating D-A converting unit.
Claim 2
Dependent Claim
178 words
An A-D converter for use in an electronic balance, comprising: a pulse-modulating D-A converting unit which converts an input digital signal to an analog output signal; an analog subtracter which subtracts said analog output signal of said pulse-modulating D-A converting unit from the analog signal to be.measured; an A-D converting unit which converts the output of said analog subtracter to a digital signal, generates an oversignal when an input signal inputted thereto overflows the same and generates an undersignal when said input signal inputted thereto falls down to zero; a digital memory which can store a digital signal corresponding to an integral multiple of the saturated output level of said A-D converting unit, the number of multiplication being equal to the difference made by subtracting the number of said undersignal from that of said oversignal; a digital adder which adds the contents stored in said digital memory to the digital output of said A-D converting unit; a leading means for leading the contents stored in said digital memory to the input terminals of said pulse-modulating D-A converting unit.
Claim 3
Dependent Claim
159 words
An A-D converter for use in an electronic balance, comprising: a pulse-modulating D-A converting unit which converts an input digital signal to an analog output signal; an analog subtracter which subtracts the analog output signal of said pulse-modulating D-A converting unit from the analog signal to be measured; a switching means for selecting either the full output signal of said analog subtracter or the signal reduced to one N-th of the same; an A-D converting unit which converts the analog output of said switching means to a digital signal; a digital memory which can store a digital signal whose value is predetermined in accordance to said signal reduced to one N-th; a digital adder which adds said signal reduced to one N-th, with the same multiplied by N, to the output of said A-D converting unit; and a leading means for leading said-digital signal stored in said digital memory to the input terminals of said pulse-modulating D-A converting unit;
Claim 4
Dependent Claim
159 words
An A-D converter for use in an electronic balance, comprising: a pulse-modulating D-A converting unit which converts an input digital signal to an analog output signal; an analog subtracter which subtracts the analog output signal of said pulse-modulating D-A converting unit from the analog signal to be measured; a switching means for selecting either the full output signal of said analog subtracter or the signal reduced to one N-th of the same; an A-D converting unit which converts the analog output of said switching means to a digital signal; a digital memory which can store a digital signal whose value is predetermined in accordance to said signal reduced to one N-th; a digital adder which adds said signal reduced to one N-th, with the same multiplied by N, to the output of said A-D converting unit; and a leading means for leading said-digital signal stored in said digital memory to the input terminals of said pulse-modulating D-A converting unit;
Claim 5
Dependent Claim
36 words
An A-D converter for use in an electronic-balance, defined in claims 1 or 2, wherein both said pulse-modulating D-A converting unit and said A-D converting unit are driven, synchronously with each other by a common clock.
Claim 6
Dependent Claim
27 words
An A-D converter for use in an electronic balance, defined in claims 1, 2 or 3, wherein said A-D converting unit is of a voltage-frequency conversion type.
Claim 7
Dependent Claim
26 words
An A-D converter for use in an electronic balance, defined in claims 1, 2 or 3, wherein said A-D converting unit is of a double-integral type.
Claim 8
Dependent Claim
26 words
An A-D converter for use in an electronic balance, defined in claims 1, 2 or 3, wherein said A-D converting unit is of a successive-approximation type.
Claim 9
Dependent Claim
100 words
An A-D converter for use in an electronic balance comprising a A-D converting unit preceded by an analogue subtractor, a digital memory which records the number of times the capacity of the A-D converting unit is exceeded, a pulse-modulating D-A converting unit connecting the memory to the subtractor to subtract from the input an integral multiple of the capacity of the A-D converting unit, and a digital adder coupled to the output of the A-D converting unit and controlled by the memory to add back to the digital output an amount corresponding to the analogue amount subtracted from the input.
Claim 10
Dependent Claim
100 words
An A-D converter for use in an electronic balance comprising a A-D converting unit preceded by an analogue subtractor, a digital memory which records the number of times the capacity of the A-D converting unit is exceeded, a pulse-modulating D-A converting unit connecting the memory to the subtractor to subtract from the input an integral multiple of the capacity of the A-D converting unit, and a digital adder coupled to the output of the A-D converting unit and controlled by the memory to add back to the digital output an amount corresponding to the analogue amount subtracted from the input.
References Cited (Backward Citations)
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