| 摘要 |
Method and apparatus for measuring the magnitude of a varying analog signal and for displaying a close approximation of a final stabilized value before the signal reaches stabilization. An analog-to-digital converter converts the analog signal to corresponding digital pulse signals and the digital pulse signals are displayed to an operator. Automatic display-hold circuitry determines the pulse count difference between successive pulse count signals separated by a predetermined time interval, compares the difference to predetermined value, and, when the predetermined value is reached, generates a control signal which locks the displayed value and prevents the display from updating as the analog signal continues to vary. The difference between pulse signals is taken by storing the first signal in an up/down counter and decrementing the counter in response to the second signal. The circuitry determines the pulse count difference and the sign of the difference between the two signals by counting either (1) the number of remaining pulses in the second signal after the counter decrements to zero or (2) the number of additional pulses required to decrement the counter to zero after termination of the second signal.
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