US Patent: 5,142,221
|
| Automatic Function Selecting Multimeter
|
|
Patentees:
|
| Glen A. Meldrum (exact or similar names) - Mountlake Terrace, Snohomish County, WA |
| Glade B. Bacon (exact or similar names) - Everett, Snohomish County, WA |
|
|
Patent Dates:
|
| Applied: |
Nov. 23, 1990 |
| Granted: |
Aug. 25, 1992 |
USPTO (New site tip)
Google Patents
Report data errors or omissions to steward
Joel Havens
|
|
Description: |
| 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.
Claim:
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. |
|
