Atari Mega Archive 1

home *** CD-ROM | disk | FTP | other *** search

/ Atari Mega Archive 1 / Atari Mega Archive - Volume 1.iso / misc / cap.arc / CAP.DOC < prev next >

Wrap

Text File | 1987-08-24 | 10.6 KB | 263 lines

The Circuit Analysis Program (CAP) is an analysis tool for determine the steady-state AC behaviour of electrical/electronic networks. The network may contain resistors, capacitors, inductors, controlled cur- rent sources (e.g. transistors, op-amps etc.) and independent current sour- ources. CAP was originally issued for the HP85, but has been adapted for the ST after a lot of re-writing and testing. Although CAP does not have the capabilies of programs like e.g. SPICE, in small AC circuit analysis however, the output results are satisfactory and in most cases accurate enough to predict the actual circuit behaviour. Output can be any node voltage, branch voltage, branch current, branch power or ratio's thereof. Tabulated or plotted outputs are available with linear or logarithmic fre- quency sweeps. CAP is primary intended for electrical engineers or those who are familiar with electrical networks and basic electrical/electronic theory. All files belonging to CAP must be located in folder CAP, including folder GUIDE, which contains several help-files. Files with the extension CIR are circuit examples, which can be loaded and analysed after frequencies and output quantities are selected and calcula- tions have been performed. NOTE: Hardcopy of full screen can be made by ALTERNATE+HELP. We will offer CAP as a public domain program for non-commercial usage and therefore assume no responsibility and shall have no liability, consequen- tial or otherwise of any kind arising from the use of this program. Ger Gruiters Rank Xerox Venray The Netherlands ---------------------------- Structure of files --------------- G6.DOC 851 \CAP\GUIDE G4.DOC 1114 \CAP\GUIDE G5.DOC 878 \CAP\GUIDE G3.DOC 1042 \CAP\GUIDE G1.DOC 387 \CAP\GUIDE G7.DOC 998 \CAP\GUIDE G8.DOC 768 \CAP\GUIDE G10.DOC 757 \CAP\GUIDE G9.DOC 643 \CAP\GUIDE G2.DOC 1035 \CAP\GUIDE BJT.PIC 32000 \CAP CAP.PIC 32000 \CAP CAP.PRG 40980 \CAP CAPNXT.RSC 20904 \CAP EX1.CIR 584 \CAP EX2.CIR 584 \CAP EX3.CIR 584 \CAP OPAMP.PIC 32000 \CAP PARAM.PIC 32000 \CAP README.DOC 1639 \CAP WIENBRDG.CIR 1358 \CAP ---------------------------- Documentation ------------------- 1.0 General program usage ===================== - Select New cir from Menu "Circuit" , select Menu "New cir" next and enter a new circuit, or load 'old' circuit from disk (filename.cir). - Select frequencies and output quantities before calculation. - Plotting is done after calculation. - Tables are output automatically during calculation. 2.0 Example of circuit description ============================== 1 IS 0 TO 1 1 AMPS 0 DEG 2 L 1 TO 2 2 E-4 H 3 R 2 TO 3 .33 OHM 4 C 3 TO 0 2.2 E-4 F 5 R 2 TO 0 20 OHM Note in the above example that circuit elements are described by their connec- ting nodes, their values, and a branch or element number. It is this branch number which is specified when requesting branch voltages, currents, or pow- ers for output. You would also specify this number when deleting an element. Due to the way the program orders itself, as you add independent current sour- ources they are added to the top of the list. As you add any other elements they are added to the bottom of the list. CAP is divide into three sections a) Input of circuit, b) Selection of output quantities and frequency sweep, and c) Plotting. These sections are completely independent in that you can change any parameter of any section and retain all other parameters. 3.0 Input of circuit ================ Circuit elements are input from the New circuit Menu, one element at a time with the required information being the element type, the connecting nodes and the value of the element, (i.e., 10 Ohm, .1 Henrys, etc.). The first thing that must be done is to number the nodes. A node, for the purposes of this program is any point where two ore more circuit elements meet. The no- des must be consecutive integers, consecutive numbered nodes need not have any special topological relationship to each other. While inputting each element, the program will ask for the connecting nodes with the following question: NODES: FROM, TO?. The FROM node is the node where the current leaves the element. For the non-source elements (resistors, inductors and capacitors), it is not important if you don't know the direction of the current flow. Simply assume one. If you assume wrong, the current will be computed 180 degrees from the expected direction. Study the example's EX1.CIR and EX2.CIR. 4.0 Selection of Output Quantities and Frequency Sweep ================================================== After a circuit has been input, but before calculation beings, you will need to select those quantities you wish to observe and the frequencies at which to ob- serve them. There are two ways that the program can provide output. printed table of up to 50 quantities per frequency, or a displayed plot. Only one method can be selected at a time. Available output quantities are node voltages, branch voltages, branch currents branch power and ratio of any two quantities. Node voltage zero is not avail- able for output, but is always 0 volts at 0 degrees. A branch voltage is the voltage across an element. It is the node voltage at the positive node minus the node voltage at the negative node. The positive node for a controlled or independent current source, by convention, is the node where the current leaves the source (the TO node). The positive node for resistors, inductors and capa- citors again by convention, is the node where current enters the element ( the FROM node. All output quantities are given in magnitude and phase format. For power this means that real power, is measured in watts at 0 degrees. Reactive or imaginary power, measured in VARS, is +90 degr. for inductors and -90 degr. for capacitors. For non- source elements power is defined as power absorbed. For source elements power is defined as power delivered. For any given circuit the complex sum of power delivered by the sources will equal the complex sum of the powers absor- bed by the elements. The frequency sweep is selected by specifying a minimum frequency, a maximum frequency, and an increment. If the increment is positive each new frequency will be the old frequency plus the increment. If the increment is negative, you have specified a logarithmic sweep with each new frequency equal to the old frequency times the absolute value of the increment. 5.0 Plotting ======== Plotting is accomplished after calculations are performed. The magnitude and phase of the output quantity selected are stored for up to 50 frequen- cies. With the same set of data you may make any number of plots. You need not select any plotting parameter. Automatic labeling and scaling are default. The automatic labeling puts out the following information: whether you're plotting magnitude or phase, the output quantity, and whether dB's are selected for ratios. If automatic labeling is not sufficient you may select any 18 characters. If you wish to select different scaling parame- ters you may select the maximum. minimum and the space between the tic marks. These parameters may be selected independently for the X and directions. You may even leave one direction automatic and select the other. 6.0 Additional explanation for some commands ======================================== New cir : Enter a new circuit, same input as add element. Add elem : Add circuit element to an already existing circuit. RES When R NODES :FROM, TO? is displayed, IND 1) Enter the node where currents enters the resistor followed by CAP a comma. 2) Enter the node where current leaves the resistor. When VALUE? is displayed enter the resistance in Ohms. The same is done when entering an inductor or capacitor where the value is entered in the resp. quantity. IS When IS NODES: FROM, TO? is displayed, 1) Enter the node where current enters the source, followed by a comma. 2) Enter the node where the current leaves the source. When AMPLITUDE is displayed, enter the amplitude in Amperes. When PHASE is displayed, enter the phase in degrees. 6.1 continued VCIS : Add a voltage controlled current source When CONTROLLING NODES: +, -? is displayed, 1) Enter the number of the positive controlling node followed by a comma. 2) Enter the number of the negative controlling node. When CONTROLLED NODES: FROM, TO? is displayed, 1) Enter the node where the current enters the controlled source followed by a comma. 2) Enter where the current leaves the controlled source. When gm is displayed, Enter the transconductance in Siemens. Del elem:To delete circuit elements when ELEMENT #? is displayed. Enter the element #, as it is numbered in the circuit descrip- tion (0 for none). 6.2 continued TABLE : Select tabular output quantities. PLOT : Select plotted output quantities. Note that both TABLE and PLOT clear any previous selected output quantity. dB : Default dB is on and all ratios are output in dB. FREQS : When MIN FREQ? is displayed, 1) Enter minimum or starting frequency in Herz When MAX FREQ? is displayed, 1) Enter the maximum or ending frequency in Herz When INC[(-) FOR LOG]? is displayed, 1) Enter an additive frequency increment OR 2) Enter the negative of a multiplicative frequency increment. 6.3 continue When output quantities are selected enter the number of the branch or node as defined by the circuit description. Note that branch power S is a com- plex number (S=V*I) and will be output in magnitude and phase format. If you wish to calculate ratio's (in most cases): 1) First select the numerator (e.g Node Voltage 2 in previous example). 2) Click next Ratio "/" (becomes shaded) 3) Select the denominator (e.g. Node Voltage 1 in previous example). If PLOT is selected ONLY 1 ratio or value can be selected at the time. If TABLE is selected up to 21 ratios or quantities can be selected. The SUPERIMPOSE function superimposes the next plot over the last plot (dashed line), using the next plot's scaling parameters.