SU651475A1 - Analogue-digital converter - Google Patents

Description

(54) ANALOGUE DIGITAL PRE (GRAE)

This invention relates to a measurement technique. An analog-to-digital converter containing comparators, reference voltage sources, is known in which a two-pole analog signal is compared with constant reference voltages of both signs 1). However, this device operates with insufficient accuracy. The analog-to-digital converter is known, which contains a comparator on a transistor, a sign comparator on a transistor, a reference voltage driver, the input of which is connected to the output of a sign comparator consisting of a transistor and a divider on resistors; the comparators' inputs are connected to the signal source 2 bus. In this device, at the moment of signal zero crossing, a quantization error may occur. The goal of the invention is to eliminate the conversion error. It is achieved by the fact that the analog-digital converter containing the comparators, the sign comparator, the reference voltage generator and the logic block are entered into two additional comparators and the AND element, and the output of the reference voltage generator through the two additional comparators and the AND element are connected to the control input logic block. The structural electrical circuit of the device is shown in the drawing. The device contains 2 comparators I, a comparator of the sign 2, a shaper of 3 reference voltages, comparators 4, 5, element 6, and block 7 of logic. An analog signal is fed simultaneously to the comparator sign 2 and. in all 2 I comparators and is compared in the latter with 2 reference voltages of one or another sign produced by shaper 3 depending on the polarity of the input signal based on the signal of comparator 2. Comparator 2 determines the sign of the input signal and changes sign at the moment of transition signal through zero. The sign of the input signal determines in which code to use the digital output of the device (in forward or reverse). Comparators 4 and 5 are given the highest value of the reference voltage produced by shaper 3, where the results are compared with the amplitude of the strongest reference voltage of shaper 3. Attenuator 3),),)) 6, at the time of the analog voltage zero crossing, a signal is generated, the duration of which is equal to the duration of the transient process of the driver 3, during which the reference voltage rises from the most negative value of yes payuzhmtelnogo cities account for major and back .--.,,

In bloge 7, the POSITIONAL code received by the KovnapaTopoB I. is decrypted into a binary code, which is a digital memory device.

During the action of the generated MCHToiM E, the output code in block 7 is zeroed in the signal. h ,, nd „. .,.;,::,:, -.

Prikenemia of the specified scheme allows you to eliminate the conversion error and increase accuracy when converting a two-pole signal.

-PF

Claims (2)

1. US patent number 3611350, 340-347, 1971. 2. US patent number 3371337. 340-347, 1% 9.  I hu pffsou Pb / KOff -and