@database AmiSPICEed.guide @Node Main "AmiSPICEed.guide" AmiSPICEed V2.1 - English Short manual This guide is meant to be an introduction to the functions and use of this program. To obtain information about the actual components and their use you have to read the SPICE manual included with the SPICE archive. @{" Introduction, Requirements and Installation " Link "Einf"} @{" README!! " Link "Recht"} @{" Window " Link "Fenster"} @{" Menus " Link "Menus"} @{" ToolTypes " Link "ToolTypes"} @{" Elements of the internal library " Link "Intern"} @{" The NE5561-model " Link "NE5561"} @{" Construction of the libraryfile " Link "BIBO"} @{" Specialities " Link "Besonder"} @EndNode @Node "Einf" "Introduction, Requirements and Installation" AmiSPICEed is a graphical schematic editor that enables direct input of analogue circuits into the SPICE simulator. This makes it possible to input the circuit as a schematic instead of a node list. By using the libraryfile you can input your own components into the schematic and simulation. To use the program you need at least the following: - An AMIGA with OS 2.04 or later - A harddisk - A workbench screen with 640x400 Pixel or more - Installed SPICE program. (AMINET: misc/sci/) - "amigametaformat.library" by Henk Jonas is required for EPS-export. ENGLISH MANUAL, this version written by Leif Johnsson E-mail: leffesko@algonet.se expanded by Dirk Hasse @EndNode @Node "Recht" "README!! " AmiSPICEed V2.1 is (c) in 1997 - 2000 by Dirk Hasse. AmiSPICEed V2.1 may be freely redistributed as long as no modifications are made and nothing is charged for it. Commercial usage is strictly forbidden. I am not responsible for any damage directly or indirectly caused by the usage of AmiSPICEed. Anything you do is at your own risk. If you consider the program to be useful and if you want to do something for the further development, you can transfer me some money to the following bank account: Volksbank Brilon BLZ: 41661719 Acc.-Nr.: 100881319 PPC-board, Surfboards or keyfiles are accepted to. Dirk Hasse Bernhardusstr. 34 59929 Brilon GERMANY Bug-reports, comments, questions etc. please ONLY via email: beavis@azrael.uni-paderborn.de @{" A picture of me doing what I like most... " Link "surfing.iff/MAIN"} Brilon, May 01. 2000 @EndNode @Node "Fenster" "Window" The different windows have the following functions: @{fg highlight}@{b} Edit-Window @{ub}@{fg text} This window is used for showing and editing the schematic. With the aid of the scrollbars you may move about the complete schematic. Adding components at the edge will resize the scrollable area, in this way you you can use schematics of almost infine size. ( Hmmm... or at least up to the limit of the used 32 bit position counter...) From version 1.1 the cursor keys will let you scroll without limits. When you have "glued" a component to the mouse-pointer, just Click on the wanted position on the schematic and it will be placed. The selection-point for each component is marked with a light dot (Click on it to select the component). In EDIT-MODE this point will be highlighted when the mouse-pointer is move across it. The filename and path will be shown in the window titel. From version 1.2 you can edit elements by a double-click when in EDIT-MODE. @{fg highlight}@{b} Library-Window @{ub}@{fg text} This window contains two listwievs, one with all installed libraries and one with all the components in the selected library. All libraries are ASCII-files. IMPORTANT To edit the schematic you must select EDIT_MODE in the internal library. In order to connect the components togheter you must be in this mode. @{fg highlight}@{b} Plot-Window @{ub}@{fg text} This window is opened ASYNCHRONOUS (that means, that you can continue your work in the other windows!), if a simulation is started via the menu "Run SPICE..." and succesfully performed. The voltages and currents, which where selected via the view voltage and view current elements, are graphically displayed here. The following gadgets apear at the top of the window: Close: : Close the window Save ASCII : All active plots (checkbox gadgets) can be saved as an ASCII- file with selectable name. The used delimitter can be selected by the tooltype: "DELIMITTER". Example file for DELIMITTER=TAB: time U0 U1 I0 0 1 0.5 0.01 0.1 0.5 0.67 0.023 0.2 0 0.8 0.04 Split (Join): You can choose between two possible display-modes: Joined : All voltages and currents are displayed in one plot. Spitted: Every voltage or current is displayed in a seperate plot. Add plot : The expression given in the string-gadget will be parsed and added to the plot-window. The new identifier for this plot will be Pxx. You can use normal mathematical expressions with the following restrictions and elements: - floating point values without exponents, e.g. 1.234 - variables which are already plotted in the window, e.g. U0,U1,P0,A10 ATTENTION: in AC-analysis-mode there will be the real and imaginary part of each voltage or current. In this case the use of U0 is the same as SQRT(Re(U0)^2+Im(U0)^2), the magnitude. ABS(U0) would cause the same result. - Special chars: ^,+,-,*,/,(,) - functions: ABS(x) : magnitude abs(x) = sqrt(Re(x)^2 + Im(x)^2) PHASE(x) : phase phase(x) from -Pi to Pi DB(x) : dezibel db(x) = 20*log10(x) RE(x) : real part CANNOT BE USED ON WHOLE EXPRESSIONS! Re(U0+U2) IS NOT POSSIBLE! IM(x) : imaginary part CANNOT BE USED ON WHOLE EXPRESSIONS! Im(U0+U2) IS NOT POSSIBLE! - No negative values or variables can be used. -2*U0 or 2*(-U0+U1) are invalid and CAN lead to wrong results. You could use the following trick: 0-2*U0 and 2*(U1+U0) - there's no 100% syntax-checking, so be carefull - some examples of expressions which make sense: + plot of magnitude and phase of an AC-plot: abs(U0) und phase(U0) + plot of a voltage-difference: U0-U1 On the left hand you can select which variables to plot via some checkbox gadgets. PROBLEMS: If a (nearly) konstant voltage or current is displayed in a seperate plot, the routine which draws the y-grid may get trapped in an endless loop. I don't know why, so I added a timeout after 100 loops. On my machine, it takes 1 second until the program continues to work. If the height of a plot gets too small, it may happen that no y-values are printed. You should expand the windowsize or disable some plots in this case. @EndNode @Node "Menus" "Menus" You have the following Menues at your disposal: @{" Project " Link "Project"} @{" Edit " Link "Edit"} @{" Library " Link "Library"} @EndNode @Node "Project" "Project" Contents of Project menu: @{fg highlight}@{b}Clear (sub-)circuit...@{ub}@{fg text} All components in the current schematic and it's subcircuits will be erased. @{fg highlight}@{b}Load...@{ub}@{fg text} A circuit will be loaded and the current circuit with all subcircuits will be erased. If used in a subcircuit the parent circuit will not be erased. @{fg highlight}@{b}Save...@{ub}@{fg text} The circuit will be saved to disc, including subcircuits. @{fg highlight}@{b}Save as IC...@{ub}@{fg text} The current (sub-)circuit will be saved to disc. The directory is ICs and the filename is the name of the current IC by default. @{fg highlight}@{b}Export to SPICE...@{ub}@{fg text} The circuit will be save to disc as a SPICE inputfile. @{fg highlight}@{b}Run SPICE...@{ub}@{fg text} The circuit will be simulated by SPICE and the result presented in a Plot-window. This is done in the following way: 1. The circuit will be saved to disc in a Temp-file. 2. A CLI-window is opened and the SPICE output is shown here. 3. The simulation is started by this call to SPICE 4. SPICE writes it's output to a Temp-file. 5. AmiSPICEed reads this output and opens the Plot-window. The simulation can only be started when all of the following apply - At least one Ground-connection defined - At least one voltmeter or ammeter defined - A simulation must be defined @{fg highlight}@{b}Export to TeX...@{ub}@{fg text} The circuitpart will be saved to disc in TeX-format by using the EEPIC Macrofunctions. The complete circuitpart will be saved , NOT only the visible part in the window. It may be scaled by editing the appropriate ToolTypes. @{fg highlight}@{b}Export as EPS...@{ub}@{fg text} The circuitpart will be saved to disc in EPS-format. The complete circuit- part will be saved, NOT only the visible part in the window. The postscipt- font and it's size can be configured with the tooltypes. @{fg highlight}@{b}Save window positions@{ub}@{fg text} The current window positions and sizes will be save in "AmiSPICEed.prefs". This will enable you to continue your next session with the windows in the same positions. @{fg highlight}@{b}About...@{ub}@{fg text} A Information window will be shown. @{fg highlight}@{b}Help...@{ub}@{fg text} The file "AmiSPICEed.guide" will be shown by Multiview. Multiview must be in your path. @{fg highlight}@{b}Quit...@{ub}@{fg text} This will end the program. @EndNode @Node "Edit" "Edit Menu" Contents of Edit-menu: @{fg highlight}@{b}Edit element...@{ub}@{fg text} The parameters of the selected component can be edited in a window. All compnents will have its component number as the first parameter, ie. the number following the identifier (R, L, C, ...). All other parameters are component specific and can be defined in the library file. Parameters with empty datafields will not be saved in the SPICE-file, WARNING!!: The height of the Edit-window is adapted to the number of changeble parameters. This may cause problems on small screens. (NOT TESTED) Keyboard operation: From Version 1.1 the first gadget will be activated, and all gadgets will be reachable by the TAB key. When all values are defined you may end the input by RETURN followed by "u" or "c" fore Use and Cancel. A press on SPACE will activate the first gadget. @{fg highlight}@{b}Edit stimulus...@{ub}@{fg text} The "Piecewise linear current/voltage" can be edited with graphic support. This is performed with the aid of a string gadget for input of time, amplitude pairs and a plot window for viewing the specified curve. A press on RETURN will redraw the graph, OK saves your curve and CANCEL restores the previous values. The values must be in chronological order and negative time is not allowed. Keyboard operation: When the string gadget is deactivated ie after a press on RETURN, it is possible to activate the OK Cancel and Show gadgets with the "o", "c" and "s" keys, SPACE will reactivate the string-gadget. @{fg highlight}@{b}Show subcircuit@{ub}@{fg text} After selecting an IC-module the corresponding sub-circuit will be shown. This change to a deeper hieriarcally level is indicated in the window title by an arrow (->). The titel "Receiver->Filter" means that the subcircuit "Filter" is included in the "Receiver" circuit. @{fg highlight}@{b}Return to higher circuit@{ub}@{fg text} Return to the circuit or subcircuit containing the current subcircuit. @{fg highlight}@{b}Delete@{ub}@{fg text} The selected component and all its connections will be erased. If it's an IC all of the circuits and subcircuits in it will be deleted. @{fg highlight}@{b}Move@{ub}@{fg text} The selected component can be moved to a new position. The component will be dropped when you click on a position in the schematic. All connections will be retained. @{fg highlight}@{b}Rotate@{ub}@{fg text} The selected component will be rotated 90 degrees. All connections will be retained. @{fg highlight}@{b}Flip@{ub}@{fg text} The selected component will be mirrored in the horizontal axis. All connections will be retained. @{fg highlight}@{b}Redraw@{ub}@{fg text} The schematic will be redrawn. This function is included to rectify possible graphics driver errors (Should not be neccesary but !!!) @EndNode @Node "Library" "Library Menu" Contents of Library-menu: @{fg highlight}@{b}Load...@{ub}@{fg text} You may load additional libraries from disc. At program start all libraries in the drawer bibs/ will be loaded. @{fg highlight}@{b}Remove...@{ub}@{fg text} The selected library will be removed from memory. This can not be executed on the internal library or on any library that have components in the current schematic. @EndNode @Node "ToolTypes" "ToolTypes" You have the following ToolTypes to use: @{fg highlight}@{b}SPICEEXE@{ub}@{fg text} Your Path and filename of the SPICE program. Ie. SPICEEXE=SPICE:spice_3f5 @{fg highlight}@{b}SPICEWINDOW@{ub}@{fg text} Definition for the window used by SPICE to give you information. Ie. SPICEWINDOW=CON:0/20//180/Running SPICE... @{fg highlight}@{b}PLOTCOLOUR1 to PLOTCOLOUR6@{ub}@{fg text} You can define six colour registers to be used when plotting the results. It's important to remember that Workbench places its first 4 colours in the first register and additional colours in the last register, ie PLOTCOLOUR1=127 @{fg highlight}@{b}PLOTBACKGR@{ub}@{fg text} This defines the background colour, please do not use the same colour as PLOTCOLOUR or PLOTTEXT, ie. PLOTBACKGR=0 @{fg highlight}@{b}PLOTTEXT@{ub}@{fg text} This defines the colour for the axes and text in the plotwindow, ie. PLOTTEXT=1 @{fg highlight}@{b}TEXUNIT@{ub}@{fg text} This defines the size in the TeX-output. One screen pixel gets this length in the TeX document. The value TEXUNIT=0.2mm works well with most smaller schematics. @{fg highlight}@{b}EPSFONT@{ub}@{fg text} The postscript-font for EPS-output ca be selected here. Ie. EPSFONT=Courier @{fg highlight}@{b}EPSFONTSIZE@{ub}@{fg text} Defines the size of the postscript-font in pixel, ie. EPSFONTSIZE=12 @{fg highlight}@{b}F1 to F10@{ub}@{fg text} You may create shortcuts to selected components via F1 to F10, including the EDIT-MODE. The function key must have both the library name and component name given, comma separated, like this: F1=Internal elements,EDIT-MODE This will activate the EDIT-MODE in the Internal library via the F1 key. Errors in the decoding of the key definition will not be reported, but the the key will be undefined. @{fg highlight}@{b}SCREENMODE@{ub}@{fg text} If this tooltype is defined, AmiSPICEed will start on it's own custom- screen with the given mode-ID (hex-value). For a PAL-HIRES-INTERLACED screen you have to enter: SCREENMODE=$00029004. @{fg highlight}@{b}SCREENCOLS@{ub}@{fg text} If AmiSPICEed opens an own customscreen, you can define EXACTLY 8 colors. Each gun is desribed by 4 bits ($0 to $f). The tooltypes PLOTCOLOUR1 to PLOTCOLOUR8 and PLOTTEXT, PLOTBACKGR must be used, too. Example: SCREENCOLS=$bbb,$000,$fff,$06A,$1f1,$e2e,$fe2,$e33 @{fg highlight}@{b}DELIMITTER@{ub}@{fg text} The delimitter for the ASCII-output of all active plots in the plotwindow can be selected here. Possible strings are: "SPACE", "TAB" or a character of your choice. Example: DELIMITTER=SPACE @{fg highlight}@{b}DRAWVALUES@{ub}@{fg text} The values of some elements can be printed to the edit window too, if this tooltype is set. (eg. RO (10k)) Currently the elements resistor, capacitor and inductor are supported. @{fg highlight}@{b}GRID@{ub}@{fg text} A visible grid can be selected by the tooltype GRID=ON. @EndNode @Node "Intern" "Elements of the internal library" Contents of the Internal Library: @{fg highlight}@{b}EDIT-MODE@{ub}@{fg text} This element is activated to edit the schematic. Components can be selected operated on by the commands in the Edit-menu. You also use this item to connect two components, procedure as follows: 1. Click on the selection-point in the first component. 2. Click on the connection-point in the first component From version 1.3, the first connection-point ca be selected directly, without activating the corresponding element first. A line between the mouse pointer and the connection-point is activateda: 3. Click on the selection-point in the second component. 4. Click on the connection-point in the second component From version 1.3, the second connection-point can be selected directly, too. The connection will now be drawn on the schematic. You use the same method to change alredy drawn connections. The interconnections have four hidden connection-points that can be found by moving the pointer round the selection-point, they will be highlighted ! @{fg highlight}@{b}Text@{ub}@{fg text} You can add information to the schematic with this component. The information is not used in the simulation. The Edit-menu can be used to change the text. @{fg highlight}@{b}Ground@{ub}@{fg text} GROUND, each schematic MUST have at least one ! @{fg highlight}@{b}Knot@{ub}@{fg text} If several components have to be connected together you have to use this interconnection component. Place it on the schematic and use it as a normal component. @{fg highlight}@{b}Interface@{ub}@{fg text} Used to connect to the circuit containing the subcircuit. Each Interface in the subcircuit will generate one connection-line on the IC-component in the "calling" circuit. @{fg highlight}@{b}IC@{ub}@{fg text} Used to link a subcircuit to the circuit. @{fg highlight}@{b}View voltage@{ub}@{fg text} Voltmeter, place this on the nodes you want to plot the result from. @{fg highlight}@{b}View current@{ub}@{fg text} Currentmeter, place this on the nodes you want to plot the result from. @{fg highlight}@{b}OPTIONS@{ub}@{fg text} All global simulation variables of SPICE (eg. temperature of the environment) can be altered here. @{fg highlight}@{b}Additional components...@{ub}@{fg text} These components determine the simulation parameters you want. Try not to use more than one in schematic. The parameters use SPICE commands and you will have to study the SPICE documentation to decide what you need to put here. (but then you all know SPICE by heart, or ... ;_) ) @EndNode @Node "NE5561" "The NE5561-model" Here I present you a Pulse With Modulator chip. It has all the functions needed to build a Switched Mode Power Supply (SMPS) including a Pulse by pulse current limiter. This model of the NE5561 chip is a complete model and all functions in the block-diagram are supported, including undervoltage lockout and the supply current versus supply voltage karakteristic. Here is a list of specifications that is supported in the model. Erroramplifier: spec. source Openloop gain 60db datasheet Output impedance 220 Ohm measured Output Voltage swing max 7V min 0.4V datasheet & measured Bandwidth 3Mhz datasheet Output Stage: Output Current max 40mA min 20mA datasheet Vce saturation(Ic-20mA) max 0.4V datasheet Output voltage (Vce) max Vcc+1.4V datasheet Current limiter: Trip level 0.5V datasheet Reference: Vz output 8.2V datasheet Vz impedance 10 Ohm datasheet & measured Vref 3.75V datasheet Supply current: between 10V and 22V 7mA datasheet maximum at 25V 40mA datasheet Undervoltage lockout <10V datasheet (You can supply this chip with a current source between 8mA and 40mA). Oscillator: min. capacitor 1nF SPICE limit (see below) max. duty cycle about 90% SPICE limit (see below) max. frequency I don't know for spice but in real it is 100kHz. I had a hard time to make the model work without convergence problems. I don't garranty that this won't happen in your application but if it does you have to keep severval things mind: - Pin 5 of the chip. The oscillator can be a problem if you choose a too small capacitor value, or the resistor value is too high. So, Tcharge/Tdischarge has to be smaller than 10. This will cause a max dutycycle of about 90%. - Pin 6 of the chip. This is the current limiter input. If you don't need a current limiter you can put the input to ground. But if you need one and SPICE can not converge, try this. Put in the 'OPTIONS' the statement: 'METHOD=GEAR'. SPICE will then try to solve the circuit in an other way. SPICE tip: If you have build an SMPS and you want to know what the converter does in steadystate, you can speedup the simulation by giving the output capacitor an initial value that is the same as the nominal output voltage at the nominal load. Don't forget to type in the transient analyses 'UIC' This means 'Use Initial Condition' else it doesn't work. This way you don't have to simulate the startingup of the converter cause the output voltage is allready there. Note, To simulate an SMPS circuit you realy need a fast machine with a FPU or you are waiting for hours to get some results. Have fun with, Hendrik Jan Zwerver @{" NE5561 block diagram " Link "NE5561.iff/MAIN"} @EndNode @Node "BIBO" "Construction of the libraryfile " This part of the program requires a properly syntaxed file to operate correctly ! The following rules must be followed. - Comments or empty lines are not permitted. - Identifiers MUST be written with capitals. - The files must be constructed according to the following rules including line-order. All of the files in the bibs-drawer will be loaded at program start. The files are NOT checked for proper function at read time, be warned it is possible to interfere with program operation by supplying false information. A description of the lines making up the library files follows. Only the @{fg highlight}highligted Text@{fg text} shall be included in the actual library file !! ------------------------------------------------------------------------- Library file header: ------------------------------------------------------------------------- @{fg highlight}#AmiSPICEed Library@{fg text} This line functions as file-identification. @{fg highlight}My element@{fg text} Library name, will be displayed in the Listview. ------------------------------------------------------------------------- Component description. ------------------------------------------------------------------------- @{fg highlight}#ELEMENT@{fg text} First line in the component definition. @{fg highlight}My element@{fg text} Component name, will be displayed in the Listview. @{fg highlight}ID@{fg text} SPICE-Identifier for the component. I.e. R for resistors, C for capacitors. An X means that the definition is a complete subcircuit and not a SPICE component ( example: CMOS.bib) @{fg highlight}My model@{fg text} The name of the SPICE-model or #NO_MOD if no model definition is included. | Case a: | With a model-name given the following lines defines the model, can be | several lines. The identifier PNP or NPN on the first line can be | followed by several lines of parameter definitions | ( example: bipolar.bib) | | Case b: | If the identifier X and a name for the subcircuit is given, the following | lines must contain the definition of the subcircuit. | | @{fg highlight}#SUBCIRCUIT@{fg text} | | Here you put the circuit definition with components and model descriptions | The nodes 1, 2, 3, ... will be used as interfaces to the schematic where | it is used. The number of interfaces will be defined later. | | From version 1.3 you can use parameters in subcircuits by using the | following shortcuts: #1, #2, ... ,#9. These shortcuts will automatically | be replaced by the given parameter-values later, and they have to be used | in the identifier-field of the following parameter description, too. | A resistor and a capacitance could be described like this: | ... | R1 1 2 #1 | C1 2 3 #2 | ... | @{fg highlight}#END_MOD@{fg text} | | This line end the model or subcircuit definition. @{fg highlight}MODE@{fg text} This line is leftover from previous program revisions. The meaning is not defined but the string #NO_MODE must be placed in this position for now. Here comes the parameters that are written after the node-numbers in the SPICE inputfile (i.e. resistance value). It is possible to have several parameters listed after each other even without identifier. The program will generate a window where all parameters may be edited. The parameters consists of 3 lines. @{fg highlight}Description@{fg text} This line is presented in the Parameter window to identify the parameter. @{fg highlight}Identifier@{fg text} Identifier written in front of the parameter value in the SPICE inputfile. I.e. IC= for the parameter initial condition. If no identifier is needed the string #NO_IDENTIFIER must be included (i.e. resistance value) From version 1.3 you can define the corresponding shortcuts (#1 to #9) here, if the element is descibed by a subcircuit with parameters. EVERY USED SHORTCUT HAS TO BE DESCIBED HERE! An example is the "transformer"-element in the "passive elements"-library. @{fg highlight}Parameter@{fg text} Default value of the parameter or a empty line. The next parameter definition may start here. @{fg highlight}#END_OPTS@{fg text} This line indicates the end of the parameter definitions. The next lines deals with the definition of nodes. You may define several nodes for each component. Each node definition contains 2 lines. @{fg highlight}My knot@{fg text} Name of the node. (i.e. Base, Emitter, Collector) @{fg highlight}x,y,direction@{fg text} x and y are positions of the connectionpoint relative to the component reference position, both are counted in pixels and have to be in increments of 10. Direction sets the direction from the reference position and can be one of 4 possible, #DIR_LEFT,#DIR_RIGHT,#DIR_UP,#DIR_DOWN The next node definition may start here. @{fg highlight}#END_KNOTS@{fg text} This line indicates the end of the node definitions. The last part deals with the graphical representation in the schematic You design the symbol with lines, circels and text, the definition can extend over several lines. @{fg highlight}command,x1,y1,x2,y2@{fg text} command sets the type of graphic element: L : Line C : Circle N : Component name shown S : SPICE-Identifier with component number shown x,y values are in pixels relative to the reference point (0,0), this is also the mouse selection point. L : x1,y1 Startingpoint, x2,y2 Endingpoint C : x1,y1 Centerpoint, x2,y2 Radius N,S: x1,y1 Position, x2=3D0,y2=3D0 @{fg highlight}#END_GRAPH@{fg text} This line indicates the end of the graphic definition and the end of the component definition. The next line can be the start of another component by placing the string #ELEMENT in it. @{fg highlight}#END_BIB@{fg text} The last line in the libraryfile. Any lines following this will be ignored. That's it folks ! Anyone considering writing or enlarging a library must check the SPICE syntax requirements and maybe provide resonable default values for the required variables. @EndNode @Node "Besonder" "Specialities" @{fg highlight}non-linear controlled voltage/current (B-source)@{fg text} The non-linear controlled sources in the "sources" library can be used within AmiSPICEed as it is described in the SPICE manual. But whenever voltages of given points in the circuit shall be used, there is a little divergence from the normal notation which is caused by the algorithm AmiSPICEed is using. Normally, V(1) means the voltage of knot "1" in the *.cir circuit-file. AmiSPICEed distributes these knot-numbers dynamically, so that no one could know this at creating-time. If you want to use the voltage of a given point of the circuit in an expression of a no-linear controlled source, you have to do the following: - At the given point you HAVE to place a "knot"-element from the "internal library". - Double click the knot, so that the edit-window opens. Give the knot a defined number (e.g. 1) - In the expression of the non-linear source, you can refer to the voltage of this knot by entering V(1) Expressions like V(1,2) are not allowed and must be replaced by (V(1)-V(2)). The example circuit "B-Test" realises a multilpication of two voltages over two resistors. The functionality should be visible there. @EndNode