CALCULATOR

Abstract: An electronic calculator (1) operable to provide data for use in scientific calculations comprises a keyboard (2) and command keys (5) for a variety of functions. The calculator (1) may be used to determine molecular weights, percentage yields in chemical calculations and percentage elemental composition of chemical compounds.

Description: "Calculator" This invention relates to a calculator, in particular to an electronic calculator for use in calculations with chemical formulae. The calculation of molecular weights and other manipulations of chemical formulae is often a laborious process: the atomic weight must be known or looked up in tables for that purpose and the calculations for compounds or molecules of larger molecular weight, though simple enough, are time-consuming and tedious. In scientific research, in education and in industry a quick calculation of molecular weights and molar ratios is often required, for example when setting up an experiment or monitoring the progress of a reaction by checking percentage yields. Percentage elemental composition of chemical compounds is also a vital aspect of chemical analysis. German Patent Application No DE-A-2748951 describes an electronic calculator which provides atomic weight data for a set of chemical elements. Said data is displayed by pressing an appropriate key for a certain element. The keys are dedicated: they can only be used for one function which is to provide one piece of information for that one element. This thereby limits the function of the calculator as regards both the variety of the information provided for any one element and the number of elements one can query. On the basis of the calculator described in the German Application, a keyboard having in excess of 100 keys would need to be provided in order to obtain information about every known element. This information would be limited to a single readout, corresponding to the atomic weight of the element; no screen record would be available for chemical notation. According to the present invention there is provided an electronic calculator which provides data for use in scientific calculation, comprising input means, a processor unit, memory means and output means, the input means including alphabetic keys operable to identify chemical entities by their customary alphabetic symbols, and the memory means comprising pre-set information and programs, said pre-set information including data for each entity, and the programs being operable to perform calculation or display functions using pre-set data for the identified entities. Preferably, said data includes physical data for a range of elements. For example, said data may comprise for any one element, any one or more of atomic weight, atomic number, group, valency and electronic state. Time, stop watch and alarm functions and scientific functions and constants may also be included. Preferably also, said programs and pre-set information are arranged so that inputting a chemical symbol to represent an element on the input means and pressing other functions results in the information for said element being displayed by the output means. Said output means is preferably a liquid crystal display (LCD) and the calculator is preferably provided as a portable instrument, for convenience. Further according to the present invention there is provided a method of programming a calculator comprising providing data relating to chemical elements and programming said calculator to store said data in a fixed memory means. The fixed memory means is preferably a read-only memory. Said input means preferably comprises a keyboard which has both alphabetical and numerical representations and other symbols. An embodiment of the invention will be described with reference to the accompanying drawing. A calculator 1 may be operated to provide data for use in scientific calculations and comprises input means in the form of a keyboard 2 which comprises letters of the alphabet 3 and figures 4 plus command keys 5 for a variety of functions. The main functions available are as follows: a) Data for each of 105 or more elements; including atomic weight to two or more decimal places, atomic number, valency, group and electronic states. These data are preprogrammed into a read-only memory of the calculator and so are available when the machine is switched on. For example: Sodium Atomic Weight 22.9898 Atomic Number 11 Valency 1 Group (IUPAC 1986) 1 Electronic States (Ne)3s b) Standard arithmetic functions, including standard memory functions, M+,M-,MR,MC and percentage and reciprocal facilities. The manipulation of the atomic weights gives molecular weights, percentage elemental composition, percentage reaction yields, mole fractions etc. The calculator comprises three logical sections, input, output and processing, plus other components. These are an input device (a set of key switches), an output device (an LCD display) and a processing unit in the form of a microcomputer. The support components control the power supply in order to drive the display and processing elements. The input section comprises a set of switches, enabling input of letters, numbers and other symbols needed to specify data and operations to be performed on that data. This includes mechanisms to turn the unit on and off. The display section is able to visually represent such upper and lower case letters and numbers in plain, superscript and subscript forms and other characters necessary to the output of results and to display input data and commands whilst they are being entered. This is achieved by a dot matrix LCD display capable of displaying a number, for example 10 or more, of characters in at least one line and displaying the characters in the form of a set of dots making up the shape of the character. Thus, any character is capable of appearing in any position on the display. The character set is presented to the display by a controller device which contains, either in ROM, RAM or some other storage system, the dot patterns needed for each and every character. This controller may be part of the processing unit or may be a separate component. It is connected directly to the display section and any power supply components needed for correct operation. The processing unit is connected directly to the input section and is able to detect both switch activation and which switch was operated. The input from the switches is used by the processing unit to select from a range of operations it is capable of (arithmetic, data retrieval etc). This data, along with the results calculated, is used to pass data to the display controller for visual representation. The processing section is able to control, possibly via the support components, the supply to itself, the controller and the LCD display. The data used by the processing unit is stored in RAM, ROM or some other medium either as a part of the processing unit or by external device(s) connected to it. The calculator is preferably portable and able to operate from an internal battery. There may be other power supplies either replacing the battery or working in conjunction with it. These may include mains supply and/or Solar cells. Chemical symbols and formulae are displayed on the LCD as written by chemists, eg, C 41 H 36 ClFe0 4 P 2 h, (NH. ) 2 S0 4 < Ph 3 PO, Et 2 S. If a molecule is very large, for example, (HO) 2 C 6 H 3 CH(OH)CH 2 NHCH(CH 3 ) 2 . H0 2 CCH(OH)CH(OH)C0 2 H the scroll facility may be used. Various applications of the calculator will now be described to exemplify its use. 1. In order to display data on a particular element, eg, Sodium (Na) press: N SHIFT A DATA = The display will show: ELEMENT A.N. A.WE. VAL Na 11 22.990 1 (Alternatively the display may show this data in another form, for example: Na MASS = 22.990) Pressing DATA again shows: ELECT.ST. GROUP 2 s 6 p 1 s IVA where ELECT. ST. electronic state A.N atomic number A.Wt atomic weight VAL valency Pressing DATA again gives the first display and pressing DATA yet again gives the second display and so on alternately. In order to input a different element, enter the elemental symbol. For example, for data on carbon press: c = the information will then be displayed. 2. In order to calculate molecular weight for example, C 6 H-, 3 0C1 press: C 6 H 1 3 0 C SHIFT L The display will show the formula C 6 H 13 0C1. Pressing "=" gives the molecular weight. The molecular weight of (NH 4 ) 2 B 4 0 7 .4H 2 0 can be calculated as follows: press () N H 4 SHIFT () 2 B 4 0 7 . 4 H 2 0 The display will show the formula (NH 4 ) 2 B 4 0y.4H 2 0, Pressing "=" gives the molecular weight. 3. In order to add and subtract molecular weight for example, H 2 S0 4 + 2NaOH - 2H 2 0 press: H 2 S 0 4 + 2 N SHIFT A O H - 2 H 2 0 = 4. In order to obtain fractions of molecular weight, eg, 0.3 mols Ph 3 P press: O . 3 P SHIFT H 3 P = 5. In order to calculate the number of moles represented by a given weight of compound, for example, 0.2g H 2 S0 4 press: H 2 S 0 4 = REC * . 2 = or .2 H 2 S 0 4 Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims: CLAIMS 1. An electronic calculator which provides data for use in scientific calculation, comprising input means, a processor unit, memory means and output means, the input means including alphabetic keys operable to identify chemical entities by their customary alphabetic symbols, and the memory means comprising pre-set information and programs, said pre-set information including data for each entity, and the programs being operable to perform calculation or display functions using pre-set data for the identified entities. 2. An electronic calculator which provides data for use in scientific calculation as claimed in Claim 1, wherein the data includes physical data for a range of elements. 3. An electronic calculator which provides data for use in scientific calculation as claimed in Claims 1 or 2 , wherein the data comprises any one or more of time, alarm, scientific functions and physical constants. 4. An electronic calculator which provides data for use in scientific calculation as claimed in any one of the preceding Claims, wherein said programs and pre-set information are arranged so that inputting a chemical symbol to represent an element on the input means and pressing other functions results in the information for said element being displayed by the output means. 5. An electronic calculator which provides data for use in scientific calculation as claimed in any one of the preceding Claims, wherein said output means is a liquid crystal display (LCD). 6. An electronic calculator which provides data for use in scientific calculation as claimed in any one of the preceding Claims, wherein the calculator is provided as a portable instrument. 7. A method of programming a calculator comprising providing data relating to chemical elements and programming said calculator to store said data in a fixed memory means. 8. A method of programming a calculator as claimed in Claim 7, wherein the fixed memory means is a read-only memory. 9. A method of programming a calculator as claimed in Claims 7 or 8, wherein the input means comprises a keyboard which has both alphabetical and numerical representations.

Inventors: BRADBURY CHARLES KINDER, BRADBURY, CHARLES, KINDER
Applicants: ST ANDREWS ELECTRONICS LTD, ST ANDREWS ELECTRONICS LIMITED
Application year: 1990
Main classification: G06F15
IPC codes: G06F15