GB1402636A - Automatic calibration of digital voltmeter - Google Patents

Automatic calibration of digital voltmeter

Info

Publication number
GB1402636A
GB1402636A GB2791372A GB2791372A GB1402636A GB 1402636 A GB1402636 A GB 1402636A GB 2791372 A GB2791372 A GB 2791372A GB 2791372 A GB2791372 A GB 2791372A GB 1402636 A GB1402636 A GB 1402636A
Authority
GB
Grant status
Application
Patent type
Prior art keywords
circuit
source
reference source
voltage
comparator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2791372A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bradley Ltd G & E
Bradley Ltd G E
Original Assignee
Bradley Ltd G & E
Bradley Ltd G E
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/252Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques using analogue/digital converters of the type with conversion of voltage or current into frequency and measuring of this frequency
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03MCODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00Analogue/digital conversion; Digital/analogue conversion
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03MCODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12Analogue/digital converters
    • H03M1/50Analogue/digital converters with intermediate conversion to time interval

Abstract

1402636 Analogue to digital converters G & E BRADLEY Ltd 7 May 1973 [14 June 1972] 27913/72 Heading H3H An analogue to digital converter comprises a reference source 4, a circuit 1 in which the analogue signal is compared with the reference source and a circuit which compensates variations in the level of the reference source, the compensation circuit including a comparator 7 which compares the output of the converter during a calibration cycle with a level representative of the level of a calibration source 19 and an adjustment circuit 13, 14 responsive to the output of the comparator, the output of the adjustment circuit being added to or subtracted from the reference source 4. The converter is preferably a dual ramp converter in which the integrating circuit 1 controls a gate 6 to enable clock pulses to be accumulated in a display counter 5, the count being a digital representation of the analogue voltage fed to a terminal 22. At intervals determined by a timing circuit 20 a switch 21 is changed over to connect the accurate calibration source 19 to the circuit 1 and the reference input of the comparator 7 is fed with a count equivalent to the voltage of the source 19. If the voltage of the reference source 4 differs from that of the calibration source 19, the comparator 7 causes an exclusive- OR gate 8-10 to hold open a gate 11 for a duration proportional to the magnitude of the difference. The clock pulses fed to a counter 12 energize relays 13 to connect a voltage V via binary weighted resistors 14 to the reference source 4, thereby adjusting the reference source voltage.
GB2791372A 1972-06-14 1972-06-14 Automatic calibration of digital voltmeter Expired GB1402636A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2791372A GB1402636A (en) 1972-06-14 1972-06-14 Automatic calibration of digital voltmeter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2791372A GB1402636A (en) 1972-06-14 1972-06-14 Automatic calibration of digital voltmeter

Publications (1)

Publication Number Publication Date
GB1402636A true true GB1402636A (en) 1975-08-13

Family

ID=10267325

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2791372A Expired GB1402636A (en) 1972-06-14 1972-06-14 Automatic calibration of digital voltmeter

Country Status (1)

Country Link
GB (1) GB1402636A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0039737A1 (en) * 1979-11-21 1981-11-18 Motorola, Inc. Analog to digital converter and method of calibrating same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0039737A1 (en) * 1979-11-21 1981-11-18 Motorola, Inc. Analog to digital converter and method of calibrating same
EP0039737A4 (en) * 1979-11-21 1984-03-26 Motorola Inc Analog to digital converter and method of calibrating same.

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Legal Events

Date Code Title Description
PS Patent sealed
PLNP Patent lapsed through nonpayment of renewal fees