Title of Invention

"DOUBLE-RANGE MEASURING AND SAMPLING DEVICE FOR ALUMINUM ELECTROLYTIC CELL CONTROLLER"

Abstract Double-range Measuring and Sampling Device for Aluminum Electrolytic Cell Controller The present invention discloses a double-range measuring and sampling device for an aluminum electrolytic cell controller, wherein the input end of the operational amplitude limiter is connected to a resistance attenuator composed by a resistor, the output signals of the operational amplitude limiter and the resistance attenuator are concurrently put into an input end of a signal synchronizer composed by a voltage frequency converter, the output pulse frequency at the output end of the signal synchronizer is put into an input end of an optoelectronic isolator, and the output end of the optoelectronic isolator is connected to a program control timer. In the present invention, after the input signal is converted by the double-range VFC, the output pulse of VFC chip is sent to the program control timer via the optoelectronic isolator and then converted into digital quantity via time-setting of a common clock and controllable counting. When the present invention is used, data can be read on a bit and lines in series basis only by using I/O point of PLC. The present invention has advantages of a simple structure, a high measurement precision, a low manufacturing cost and stable operation.
Full Text

FPME05140025IN
Double-range Measuring and Sampling Device for Aluminum Electrolytic Cell Controller
Technical Field of the Present Invention
The present invention relates to voltage measurement for aluminum electrolysis production, especially relates to a double-range measuring and sampling device for an aluminum electrolytic cell controller.
Background Art of the Present Invention
At present, in the conventional voltage signal measuring and sampling system for aluminum electrolytic production by means of aluminum electrolytic cell controller, an analog quantity is often subject to isolation conversion of high common mode voltage signals by using an individual "isolation converter", which output signal is send to A/D conversion channel of a computer for conversion into a digital quantity, wherein the isolation mode is "linear chopping transformer isolator". This mode has many defects when applied to electrolytic aluminum production, wherein the biggest defect is that when the mode is applied so much, many apparatuses are needed, electric circuit is complicated and a large amount of investment is needed. In the meantime, the single input and output linear relation of the isolation converter cannot satisfy the requirements of low-range high resolution/high precision and high-range broad scope. If this isolation converter is used, to solve the above problem, input of each analog quantity requires occupancy two isolation converters and two A/D conversion channels, which leads to the problem of a too high cost. For example, an electrolytic cell often operates at a voltage of less than 5V, but every day it has an effect region in which it operates at more than 30-60V, even up to 100V,

for a period of time, so these voltages need to be measured. A voltage of less than 5V is a region of normal production and automatic control, which requires a high resolution and measurement precision (an error of less than lOmv, 0.2%); a voltage of 5V-100Vm, only a precision of 0.5% is needed. It is obviously not feasible for an individual converter to require the precision of lOmv for the conversion within the measurement scope of 0-100V and 12-bit A/V sampling. Even if the conversion has a precision of 0.2% and a resolution of 10000, the resolution and precision within the range of 0-5V are still very low.
Summary of the Present Invention
The present invention is constituted as follows: it comprises an operational amplitude limiter (1) composed by an operational amplifier and having an input end connectable to the input voltage signals to be measured, wherein the input end of the operational amplitude limiter (1) is connected to a resistance attenuator (2) composed by a resistor, the output signals of the operational amplitude limiter (1) and the resistance attenuator (2) are concurrently put into an input end of a signal synchronizer (3), the signal synchronizer (3) outputs signals to an input end of an optoelectronic isolator (4), and the output end of the optoelectronic isolator (4) is connected to a program control timer (5); the operational amplitude limiter (1) is further connected to a turning point regulation and temperature compensation circuit (6) composed by resistors Rl, R2 and a diode Dl in series; a range display alarm circuit (7) consisting of resistors R3, R4, an audion BG, a diode D2 and a voltage regulator tube W is connected between the output end of the operational amplitude limiter (1) and the optoelectronic isolator (4), wherein the base electrode of the audion BG is connected to the output end of the operational amplitude limiter (1) via R3, and wherein the diode D2 and the voltage regulator tube W are connected in series to an emitter electrode of the audion BG.
By adopting the above technical solution, the present invention realizes non-linear double associated measuring-ranges conversion of VFD dual broken lines,

it employs optoelectronic isolation technology of pulse quantity in the prior art, pulse quantity multi-path shift technology and pulse quantity/digit conversion technology, wherein so far the double-measuring-range VFD non-linear conversion technology is not applied to a centralized-type super-sized electrolytic cell controller. The electrical circuit of the present invention uses an operational amplifier and a VFC voltage frequency converter means, resulting in a pulse output of 0-5000P/S within the range of 0-5VDC and a resolution of 5000P/S, a pulse output of 5000-10000P/S within a high voltage stage 5-60VDC (maximum of 100VD) still with a resolution of 5000P/S pulse. According to the present invention, the VFC chip is used for voltage frequency conversion as well as used as a signal synchronizer. The operational amplifier is allowed to conduct linear amplification at the low input voltage measurement range stage; it conducts a precise amplitude limitation at the high input voltage measurement range stage (above the turning point), but works in a unsaturated state, so there is still a very high precision at the high measurement range stage and the critical turning point of the high and low measurement range stages is very acute with only a l-2mv slow change; the turning point is stable and can be regulated as desired and the turning temperature shift also can be regulated (generally need not be regulated); besides, measurement range display (or turning point alarm display) is provided. In the present invention, after the input signal is converted by the double-range VFC, the output pulse of VFC chip is sent to the program control timer via the optoelectronic isolator and then converted into digital quantity via time-setting of a common clock and controllable counting. When the present invention is used, data can be read on a bit and lines in series basis only by using I/O point of PLC. Therefore, as compared with the prior art, the present invention has advantages of simple structure, a high measurement precision, a low manufacturing cost and stable operation.
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above described drawings.

Brief Introduction of the Drawings
Fig. 1 is a block diagram of the principle of the present invention; Fig. 2 is a schematic view of circuit principle of the present invention, wherein the figures beside the integrated circuit modules are serial numbers of the module pins; Fig. 3 is a schematic view of output characteristic curves of the operational amplitude limiter, resistance attenuator and the signal synchronizer according to the present invention, wherein I is the output characteristic curve of the operational amplitude limiter, II is the output characteristic curve of resistance attenuator and III is the output characteristic curve of the signal synchronize after the output signal of the operational amplitude limiter and the output signal of the resistance attenuator is superposed and converted by the signal synchronizer.
Modes for Carrying out the Present Invention
According to one embodiment, upon making the present invention, the operational amplitude limiter (1), the resistance attenuator (2), the signal synchronizer (3), the optoelectronic isolator (4), the program control timer (5), the turning point regulation and temperature compensation circuit and the range display alarm circuit (7) are all assembled on one printed circuit board, wherein the operational amplitude limiter (1) can directly use a conventional operational amplifier and connected in place as per peripheral circuits of the conventional operational amplifier so that the input end of the operational amplitude limiter (1) is connected to the input voltage signal Vin measured, the input end of the operational amplitude limiter (1) is further connected to a resistance attenuator (2) composed by a resistor R5 and %{i^ in series, the output signals of the operational amplitude limiter (1) and the resistance attenuator (2) are concurrently put into an input end of a signal synchronizer (3) which can be VFC32 model voltage frequency converter available in the market, the output pulse frequency signal of the output end of the signal synchronizer (3) in

accordance with practices are put into an input end of an optoelectronic isolator (4) which can directly be assembled from the finished product available in the market, and the output end of the optoelectronic isolator (4) is connected to a program control timer (5) which can be the Model CD14536 program control timer directly available in the market; to facilitate regulation of voltage amplification turning point, a turning point regulation and temperature compensation circuit (6) composed by resistors Rl, R2 and a diode Dl in series can be connected to the peripheral circuit of the operational amplifier of the operational amplitude limiter (1); to facilitate measurement range display or alarming, a range display alarm circuit (7) consisting of resistors R3, an audion BG, a diode D2 and a voltage regulator tube W can be connected between the output end of the operational amplitude limiter (1) and the optoelectronic isolator (4), wherein the base electrode of the audion BG is connected to the output end of the operational amplitude limiter (1) via R3, and wherein the diode D2 and the voltage regulator tube W are connected in series to an emitter electrode of the audion BG. In the present invention, +15V and 12V DC power sources are used as power source as required by the integrated circuit module used in the present invention.
While there have been shown and described what are present considered to be the preferred embodiments of the invention, it will be apparent to those ordinary skilled in the art the various changes and modifications can be made herein without departing from the scope of the invention as defined by the appended claims.



Claims
1. A double-range measuring and sampling device for an aluminum electrolytic cell
controller, comprising an operational amplitude limiter (1) composed by an
operational amplifier and having an input end connectable to the input voltage signals
to be measured, characterized in that the input end of the operational amplitude limiter
(1) is connected to a resistance attenuator (2) composed by a resistor, in that the
output signals of the operational amplitude limiter (1) and the resistance attenuator (2)
are concurrently put into an input end of a signal synchronizer (3), in that the signal
synchronizer (3) outputs signals to an input end of an optoelectronic isolator (4), and
the output end of the optoelectronic isolator (4) is connected to a program control
timer (5).
2. The double-range measuring and sampling device for an aluminum electrolytic cell
controller as claimed in claim 1, characterized in that the operational amplitude
limiter (1) is further connected to a turning point regulation and temperature
compensation circuit (6) composed by resistors (Rl, R2) and a diode (Dl) in series.
3. The double-range measuring and sampling device for an aluminum electrolytic cell
controller as claimed in claim 1, characterized in that a range display alarm circuit (7)
is constructed of resistors (R3, R4), an audion (BG), a diode D2 and a voltage
regulator tube (W), and the range display alarm circuit (7) is connected between the
output end of the operational amplitude limiter (1) and the optoelectronic isolator (4),
wherein the base electrode of the audion (BG) is connected to the output end of the
operational amplitude limiter (1) via R3, and wherein the diode (D2) and the voltage
regulator tube (W) are connected in series to an emitter electrode of the audion (BG).


Documents:

1154-CHE-2005 OTHER PATENT DOCUMENT 23-09-2009.pdf

1154-che-2005-abstract.pdf

1154-che-2005-claims.pdf

1154-che-2005-correspondnece-others.pdf

1154-che-2005-description(complete).pdf

1154-che-2005-drawings.pdf

1154-che-2005-form 1.pdf

1154-che-2005-form 3.pdf

1154-che-2005-form 5.pdf


Patent Number 246935
Indian Patent Application Number 1154/CHE/2005
PG Journal Number 12/2011
Publication Date 25-Mar-2011
Grant Date 22-Mar-2011
Date of Filing 19-Aug-2005
Name of Patentee CHINA ALUMINUM INTERNATIONAL ENGINEERING CORPORATION LIMITED
Applicant Address B-15/F., TONGTAI MANSION, 33 JINRONG STREET, XICHENG DISTRICT, BEIJING 100032.
Inventors:
# Inventor's Name Inventor's Address
1 WANG, Shendu 208 BEIJING ROAD, GUIYANG CITY, GUIZHOU PROVINCE 550004.
PCT International Classification Number G01L9/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 200420060877.1 2004-08-20 China