US3426333A - System for the transfer of analogue data - Google Patents

Description

Feb. 4, 1969 5.13514: EUGENIO 3,426,333

SYSTEM FOR THE TRANSFER OF ANALOGUE DATA Filed on. a9. 1965 Sheet or 5 POWER AMPUFIER .PECEIVIN MEANS Beniamino De/IEugenio INVENTOR.

BY x Attorney Feb'. 4, 1969 B. DELL EUGENIO SYSTEM FOR THE: TRANSFER OF ANALOGUEDATA Filed Oct. 29, 1965 Sheet VOLTAGE AMPLIFI E R POWER AMPLIFIER BY 8. Del/Eugenio Feb. 4, 1969 a. DELL sussmo 26,3

SYSTEM FOR THE TRANSFER OF ANALOGUE DATA Filed Oct. 29, 1965 Sheet 3 015 Beniamino DeII'Eugenio.

I N VENTOR.

United States Patent 52,835 64 US. Cl. 340173 6 Claims Int. Cl. Gllb /02 ABSTRACT OF THE DISCLOSURE A device for the transfer of sequences (or transfer in seriatim) of analogue values representing the maxima of analytical data from a chromatograph, wherein the chromatograph-recorder servomotor (2), which drives the recording pen, is constantly connected to a temporary storage device of potentiometric type (3), and operates the storage device to generate and then temporarily store an analogue value corresponding to the data, the transfer device including :a switch system (A, B, C), e.g., via a slip clutch (1, 1a, 4, 4a, 4b, 5, 6, 7) and a bistable contact (8, 8a) or a phase discriminator (from 13 to 18), and two impedance amplifier adapters (A B responding to reversal of the motor (2) for initiating a switching sequence in which system tw switch means (A, B) control the motor (2) and consequently the temporary storage potentiometer (3), so that the motor (2) stops when upon a slope change in the electric pulses it is detected by the chromatograph, and another switch (C) connects the temporary storage potentiometer (3) to a calculator, magnetic memory or other processing system (9), the same motor (2) being successively restarted to restore the temporary storage potentiometer (3) for the receipt of further inputs.

The present invention refers to the field of component analysis and, more particularly, to analyses involving the plotting of data relevant to the concentration of components of a mixture as detected by chromatographic apparatus; such apparatus is essentially constituted of means electrically responsive to the analyzed data. More specifically, the invention concerns a device designed to transfer such analysis data in seriatim for their subsequent evaluation and/ or elaboration.

As well known, these analysis data are at present detected by chromatographic apparatus whose means electrically responsive to the analyzed data (usually comprising a small electric motor) supplies electric pulses whose amplitudes represent the concentrations of the various components of a mixture and which are usually recorded graphically upon a register driven by the small electric motor.

For evaluation and/or elaboration of the data subsequent to detection, for example by forwarding the data to signal-storage or memory means or to a calculator, it has been found in practice that it is very ditficult to assign the value of the data correctly, because each electric pulse-type signal has a maximum value or peak which is the only true representation of the analyzed component, only for a fraction of total pulse duration. Thus it is desirable to program the ancillary devices (information-storing memory or calculator) so that they continuously read the signals from chromatographic apparatus and then use only the maximum values of the representative function of the analysis. Such discriminat- 3,426,333 Patented Feb. 4, 1969 ing means, as has hitherto been proposed, has been found to be hardly practical, of limited flexibility and above all uneconomical.

It is the principal object of the present invention to provide a particularly simple device for transferring, in an unequivocal way, the maximum values of the data analyzed by a chromatographic analyzer to the reception means or devices for the evaluation and/or elaboration of the data.

According to a feature of the present invention, the input or supply of the transfer device has a structure designed to store temporarily the maximum values of the function in succession for a limited period of time and to reveal them at due time so as to supply them conveniently to the reception means for evaluation and/or elaboration. In this way the receiving means are not compelled to keep the chromatographic apparatus steadily under surveillance and, thus, the operating program of the system as considerably simplified.

A further aim of the present invention is to provide a transfer device adapted to pursue the preceding objects through a particularly efficient assembly of easy practical achievement, of a sure operational effectiveness and also of a much lower cost than pneumatic, electromechanical and electronic storing memories which are generally combined with the chromatographs to make the output continuous, in as much as it is in a position to transfer, by itself, all the peaks detected by a chromatograph, whereas a continuous storing memory would be necessary for every analyzed component.

These and other objects are reached through a device for the transfer of analysis data, particularly of the data relating to the concentration of components of a mixture as generated by chromatographic apparatus, which include means electrically responsive (a) to the analyzed data (e.g., a sensor), an amplifier/transducer circuit coupled therewith and a motor-driven recorder for registering the data. The transfer device is characterized in that it comprises:

(b) Means subjected to said electrically responsive means (a) for the temporary storage and transmission of analogue electrical values of the analyzed data,

(c) First electroswitch means for the operation of the electrically responsive means (a),

(d) Second electroswitch means for driving the first electroswitch means,

(e) Receiving means for the electric values to be transferred, operated by the first electroswitch means, and

(f) Third electroswitch means connected to the same means (b) and to the receiving means (e); said first electroswitch means (c) for the operation of electrically responsive means (a) and for the third electroswitch means (f), being driven by the aforesaid second electroswitch means (d) when said electrically responsive means (a) express the maximum electric value of the analyzed component so as to interdict these last means (a) to effect the transfer of said maximum electric value from the corresponding aforementioned temporary storing means (b) to the reception means (e) through said third electroswitch means (f).

Further characteristics and advantages will become more evident from the following detailed description of a preferred but not exclusive embodiment of the transfer device according to the invention and of a variant corresponding to a part of the same device, reference being made to the drawing in which:

FIG. 1 is a circuit diagram of the transfer device according to a preferred embodiment;

FIG. 2 is a circuit diagram of the transfer device ac cording to a variation; and

FIGS. 3A and 3B show, in greater detail, parts of the mechanical embodiment of our system (illustrated in (FIG. 1.).

As indicated earlier, the chromatographic apparatus is adapted to supply the results of the analysis in the form of electric peaking pulses or signals, includes a small electric motor suitable for actuating graphical registering means (usually a pen), the motor being represented at 2. In the embodiment of the transfer device shown in FIG. 1 of the drawing, a wheel 1, driven in a conventional way by the electric motor 2 so that its angular displacement is in proportion to the electric signal which derives from the analysis system, is associated a rotary potentiometer 3 and a clutch member 4 operating by frictional engagement with that wheel 1 under the action of a spring 5 which reacts against an arresting or stop element 6 anchored to the hub 1a of the wheel 1, in an adjustable position with respect to the friction member 4. The friction member 4 is fitted with a radial arm 4a which has at its free and a striker 4b adjustably mounted in any known way on the radial arm 4a To permit a better understanding of the operational scheme, the striker 4b is shown in FIG. 1 to lie in a plane orthogonal to its actual orientation and to the representation plane of the radial arm 4a; thus the striker 9b and the switch assembly 8 are rotated in FIG. 1 for elucidation. The arm 4a is designed to strike a member 7 for arresting it and defining a starting position. The striker 4b cooperates with the driving member 8a of a bistable electromechanical microswitch '8, whose stable positions are indicated at I and II. In series with the bistable microswitch 8 is an electromagnetic device A (first electroswitch means) having three pairs of contacts indicated at a1-a2- 03. A similar electromagnetic device indicated at B (another member of the first switch means) which has three pairs of contacts b1-b2b3, while another electromagnetic device C (third switch means) has two pairs of contacts indicated as 01 and c2. The reception means (constituted of a storing memory or of a calculator of any known type) is indicated at 9 and is schematically represented by a dot-dash line.

The above mentioned components are electrically interconnected in the following Way (see FIG. 1):

The electromagnetic devices A-B-C are actually connected in parallel with each other. Switch A being in series with the bistable microswitch 8, B being in series with the pair of contacts al-cl and having its own contacts b1 in parallel with the former contacts al, C being in series with the pair of contacts a3, which in their turn are in parallel with the pair of contacts b3. In parallel with the electromagnetic devices B and C there are furthermore inserted respectively capacitors K1 and K2 suited, as will be seen later on, for maintaining said electromagnetic devices B and C self-excited or in a hold state for a pre-established fraction of time.

One coil of the electric servomotor 2, fed by power amplifier 19 (FIG. 1), is connected in series with the pair of contacts a2-b2 in parallel with each other, while the pair of contacts c2 is inserted in the connection between the receiving means 9 and the reading means (brushes or wipers) 10 of the potentiometer 3 inserted into the mains, with one pole connected to said receiving means 9. The circuit is then completed by a main switch 11 inserted in the input or supply networks of the electromagnetic devices A, B, C.

The operation of the transfer device described above with reference to FIG. 1 takes place in the following way:

In the starting position for the analysis, as represented in FIG. 1, with the electromagnetic devices A and B unexcited and the pairs of contacts a1-a2-a3b1 open and b2-b3 closed, with C excited across the pair of contacts b3 and with its contacts 01 closed and 02 open, respectively, the electrical motor 2, one coil of which is connected to the AC. supply 20, while the other coil is supplied by power-amplifier 19 via contacts b2, by rotating, in order to express the value of the data relating to the component under examination and to transmit said value to the graphical recording means, drives also wheel 1, which forms an element responsive to the analytical data and via the temporary storage potentiometer 3, develops an electrical potential which is proportional to that value. Said wheel 1 during its rotary motion entrains the clutchlike organ 4 which by means of the striker 4b of its radial arm 4a operates the microswitch 8, by commutating the switch from position I to position II. The commutation of said microswitch 8 causes an excitation of the electromagnetic device A, and this closes the pairs of contacts a1a2a3 and energizes the electromagnetic device B, through the pairs of closed contacts a1-c1 thereby closing the pair of contacts b1 and opening the pair of contacts b2 and b3. In this position the electromagnetic device C is kept excited by the pair of closed contacts a3 while the continuity of the feeding circuit of the electric motor 2 is insured by the pair of closed contacts a2. In this way said electric motor 2 continues to rotate and to store the value of the datum under examination in the potentiometer 3 under the reading brush or wiper 10 until the maximum value of said datum under examination is reached. Once this maximum value has been attained, the electric motor 2 reverses its rotary motion thereby causing the microswitch 8 to commutate from position II to position I. In this way the electromagnetic device A is de-energized, opening its contacts al-a2-a3, the electric motor 2 is stopped in this position of the maximum value reached (because the contacts a2 and b2 are simultaneously opened) with the corresponding electrical potential temporarily stored in potentiometer 3 under brush 10, ready to be transferred to the receiving means 9, as will be seen later on; the electromagnetic device B remains excited through the pairs of contacts bl-cl, while the electromagnetic device C remains selfexcited for a pre-established fraction of time thanks to the action of the capacitor K2. Once this fraction of time elapses, sufficient for the circuits of the receiving means 9 to reach operational conditions (about 2 seconds), the electromagnetic device C de-energizes itself opening the pair of contacts 01 and closing the pair of contacts c2. In this position the electrical potential temporarily stored in the potentiometer 3 and corresponding to the maximum value of the component under examination, is transferred to the receiving or processing means 9 through the pair of closed contacts 02 and for the duration of this time of transfer the electromagnetic device B re mains self-excited due to the action of capacitor K1.

Once the transfer has been completed, the electromagnetic device B de-energizes, thereby opening its pair of contacts b1 and closing its pair of contacts b2 and b3. In this way, the electromagnetic device C becomes excited through the pair of contacts b3 and will close its own pair of contacts 01 thereby opening the pair of transfer contacts 02, as well as the motor-feeding circuit, which is restored through the pair of contacts b2; the whole device thus resumes the same starting position ready for a new cycle of analysis of another component of the mixture.

FIGS. 3A and 3B are represented to show the cooperation between the potentiometer 3, the wiper 10, the slip clutch 4, the clutch-actuated arm 4a and the servomotor 2 which, as is common on a pen recorder, has two coils. In the representation of FIG. 3A, the dot-dash block 19 represents the power amplifier mentioned in the above paragraph of this specification, while the terminals 20 are normal A-C input terminators for the servomotor. FIG. 3B shows that the member 4b actuates element 8a of the bistable switch 8 upon reversal of the motor 2 when the clutch disk 4 moves away from the abutment 7. As the specification points out, the

clutch disk slips while it is held against the stop 7 as the analogue value accumulates but, since the motor reverses, switch 8 is tripped and initiates the transfer operation.

In the variant shown in FIG. 2, parts identical or corresponding to those forming the embodiment previously described and illustrated in FIG. 1, bear the same reference numbers. This variant actually relates to that part of the device sensitive to the slope change from positive to negative value existing on top of the maximum value to be transferred; this maximum value is picked up by the electrical motor 2 and, according to this embodi ment, the displacement of the recording pen towards its maximum value, is effected through the power amplifier 19; the reversal of the pen movement is signalled respectively to the electromagnetic devices A and B by means of a phase discriminator and by two impedance amplifieradapter transistors Al-Bl. The phase discriminator consists of a double triode 13 whose plates or electrodes are fed in push-pull, through two equal electric resistances 14, by the secondary winding of a transformer 15 whose primary winding is connected to the mains.

The grids of the double triode 13, connected to each other by metal welded joints, receive through a condenser 16 a voltage having the same phase as the alternatingcurrent voltage which drives the electric balancing motor 2 of the recorder. The direction of rotation of said motor 2 depends on the phase of this voltage. Of the two triodes ISA-13B of the phase discriminator, obviously, only the one which has the plate voltage in phase with the grid voltage conducts; it follows therefore that to a certain direction of rotation of the electric motor 2 corresponds the conduction of one definite triode of the phase discriminator.

The anodic voltages of the two triodes, rectified and filtered (17 and 18), control the bases of the two transistors A1B1, respectively inserted into the circuits of the electromagnetic devices A and B.

The operation of the transfer device according to this variant is the following:

The position represented in FIG. 2 for this transfer device is equal to that of the transfer device shown in FIG. 1, i.e., to the condition corresponding to the start of the analysis of a component of a mixture, wherefore, as soon as the electric motor 2 starts to revolve in order to drive the pen of the recorder towards its maximum value, the triode 13B of the phase discriminator starts to conduct, its anode yoltage decreases, the base of transistor B1 becomes negative with respect to the emitter, said transistor B1 starts conducting and the electromagnetic device B is excited, closing its contact 111 and opening the contacts b2 and b3. Once the maximum value is reached, the electric motor 2 starts to reverse its rotation, because of reversal of the phase of the output voltage of power amplifier 19 (which feeds one of the coils of motor 2), wherefore the phase of the voltage, which controls the grids of the phase discriminator 13, inverts energizing the electromagnetic device A, which opens its contacts 412 and b3, and rendering the transistor B1 nonconductive; the electromagnetic device B, which is closed by c1 and b1 holds open the contacts b2-b3; the electric motor 2 stops. The electromagnetic device C, self-excited by the action of the capacitor K2, once the pre-established time fraction for the self-excitation has lapsed, drops and closes contacts 02 through which takes place the transfer of the maximum electrical recorded value, representative of the analyzing component, from potentiometer 3 and brush to the receiving means 9. Once the transfer has been completed, also the electromagnetic device B disconnects, resetting the whole transfer device back to the starting position, being ready for a new analysis cycle.

What I claim is:

1. In a system for the transfer of analytical data derived from an analyzing apparatus and detectable in the form of data peaks, and having an output element responsive to the data and reversible upon detection of the maxima of the data While being operable to indicate the value thereof, the improvement which comprises:

(a) a single temporary-storage potentiometer connected with said output element for generating and temporarily storing an analogue electrical value corresponding to the analytical data represented by movement of said output element;

(b) output means comprising at least one device of a memory device and a computing device responsive to an-agolue electrical values for effecting operations therewith; and

(c) circuit means connecting said temporary-storage potentiometer and said output means and controlling said output element, said circuit means including:

(c two first switch means controlling said output element for temporarily stopping same with said temporary-storage potentiometer retaining a stored analogue electrical value corresponding to a maximum of the data to which said output element responds, and for thereafter restarting said output element;

(c a third switch means for temporarily connecting said temporary-storage potentiometer to said output means for a period at least sufficient to effect transfer of the stored analogue value from said temporary-storage potentiometer to said output means in an arrested condition of said output element; and

(0 a further switch means responsive to reversal of said output element and including:

(c;,') a phase discriminator; and

(c bistable switch means for operating said two first and said third switch means in sequence and thereafter reactivating said temporary-storage potentiometer.

2. The improvement defined in claim 1 wherein:

said output element is an electric servomotor of a data register;

said temporary-storage potentiometer is connected with said motor;

said two first switch means as well as said third switch means each include a respective electromagnetically operable multicontact switch;

said phase discriminator is of mechanical type and comprises a wheel rotatable by said motor and slip clutch means cooperating with said motor and having an actuating arm bearing a striker for operating said bistable switch means; and

said bistable switch means is an electromechanical switch connected in circuit with said electromagnetically operable multicontact switches for triggering same.

3. The improvement defined in claim 1 wherein at least one of said electromagnetically operable multicontact switches is connected in a self-energizing hold circuit for delaying the deenergization thereof for said period at least sufficient to effect transfer of the stored analogue value.

4. The improvement defined in claim 1 wherein:

said output element is an electric servomotor of a data register;

said temporary-storage potentiometer is connected with said servomotor;

said two first switch means as well as said third switch means each include a respective electromagnetically operable multicontact switch;

said phase discriminator is of electronic type and comprises double-triode means having an output controlling the operating state of said bistable switch means; and

said bistable switch means is an electronic device constituted by two impedance amplifier adapters connected in circuit with said electromagnetically operable multicontact switches for triggering same.

7 8 5. The improvement defined in claim 1 wherein at least References Cited one of said electromagnetieally multicontact switches is UNITED STATES PATENTS connected 1n a self-energizing hold crrcult for delaying the deenergization thereof for said period at least sufii- 3,026,502 3/1962 Rogers et 34634 X cient to effect transfer of the stored analogue value. 5 $118,057 1/1964 S111 et a1 34633 X 6. The improvement defined in claim 1 wherein said analyzing apparatus is a chromatograph, and said two RICHARD WILKINSON Pnmmy Exammw" first and said third switch means are electromagnetically JOSEPH W. HARTARY, Assistant Examiner. multicontact switches, one of said first and said third switches having self-energizing time-constant networks for 10 US. Cl. X.R. delaying the release thereof. 7323.l; 340-177

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