Automatic function selecting multimeter
First Claim
1. A method for causing a digital multimeter to automatically select appropriate measurement functions for different types of analog signals appearing at the input terminal of the multimeter, said method comprising the steps of:
- (a) detecting the analog input signal;
(b) producing first data representative of the type of analog input signal to be measured when said analog input signal is an AC signal;
(c) producing second data representative of the type of said analog input signal to be measured when said analog input signal is a DC signal;
(d) generating function code corresponding to one of said first and second data;
(e) using said function code to cause an analog-to-digital converter to be configured to perform an appropriate conversion function on the analog input signal to be measured; and
(f) producing a display indicative of said analog input signal.
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Accused Products
Abstract
A digital multimeter having automatic function selection capability includes a signal type detector and an analog-to-digital converter formed as an application specific integrated circuit. The signal type detector has a comparator circuit that compares the analog input signal to be measured with predetermined thresholds and stores the resulting values, which are related to the type of analog input signal, in a memory that is also a part of the signal type detector. A controller executes an automatic function selection program that causes the controller to read the stored values and generate a corresponding function code, which causes an analog-to-digital converter to be configured to perform an appropriate conversion function on the analog input signal. When a change in the type of analog input signal is sensed, the controller aborts the present measurement cycle and proceeds with a next measurement cycle in which the changed analog input signal is measured. The controller also produces a change alert signal to indicate that a change in signal type has occurred.
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Citations
12 Claims
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1. A method for causing a digital multimeter to automatically select appropriate measurement functions for different types of analog signals appearing at the input terminal of the multimeter, said method comprising the steps of:
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(a) detecting the analog input signal; (b) producing first data representative of the type of analog input signal to be measured when said analog input signal is an AC signal; (c) producing second data representative of the type of said analog input signal to be measured when said analog input signal is a DC signal; (d) generating function code corresponding to one of said first and second data; (e) using said function code to cause an analog-to-digital converter to be configured to perform an appropriate conversion function on the analog input signal to be measured; and (f) producing a display indicative of said analog input signal. - View Dependent Claims (2, 3)
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4. A digital multimeter for measuring an analog signal appearing at the input terminal of the multimeter comprising:
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(a) a signal type detector for detecting said analog input signal and producing first data representative of the type of said analog input signal to be measured when said analog input signal is an AC signal and producing second data representative of the type of said analog input signal to be measured when said analog input signal is a DC signal, wherein said first data differs from said second data; (b) control means for receiving said data and producing corresponding function code; (c) conversion means for converting the analog input signal to a digital representation thereof, wherein said function code causes said conversion means to be configured to perform an appropriate conversion function on the analog input signal to be measured; and (d) a display coupled to said control means for displaying a reading of said analog input signal, wherein said control means receives said digital representation of said analog input signal and produces a related output signal that is applied to said display so as to result in said reading of said analog input signal. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
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Specification