Eagles Nest BBS 7/Eagles_Nest_Mac_Collection_Disc_7.TOAST/PD General/EWB15/Electronics WorkbenchÆ/EWBA System/ewba.hlp

Text File | 1990-09-14 | 58KB | 1,902 lines

~home||
 Overview

ELECTRONICS WORKBENCH
(C) 1988 Interactive Image Technologies

An Electronic Digital/Analog Circuit
Design and Simulation Program


   {• What you can do with EWB:purp}
   {• Parts of the screen:scrn}
   {• Building a circuit:wksp}
   {• Simulating a circuit:go}
   {• File operations:file}
   {• Program controls:ctrl}
   {• List of topics:tpx}

Point and click to get more.
~purp||
 Purpose
 Electronics Workbench can be used to

   • {construct:wksp} a schematic for an electronic
     circuit

   • {simulate:go} the activity of that circuit

   • display the circuit activity on simulated
     {test instruments:inst}

   • and {print:prt} a copy of the schematic, the
     instrument readings and parts list
~scrn||
 Appearance
 The program models a workbench for electronics.

 The large central area on the screen acts as a
{breadboard:wksp} for circuit assembly.

 On the left side of this {workspace:wksp} is a
{bin of parts:bin}.

 Above the workspace is a shelf of
{test instruments:inst} and {program controls:ctrl}.

 You may wish to read about {common operations:ops}
for the {workspace:wksp}.

{List of topics:tpx}
~inst||
 Instruments
 To use the {test instruments:ti1}

      {• put them on the workspace:wksp}
      {• attach wires to test points:ti2}
      {• zoom them open:ti3}
          to adjust the controls
          to see the display

{instruments:ilst}
~ti1||
 Test instruments
 The left end of the shelf at the top of the screen
holds test instruments.

 Handle the icons for the instruments just as you
do parts, except that there is only one copy of
each instrument.

 To use the test instruments, you must put them on
the {workspace:wksp} and {run wires:ti2} from them to the
points in the circuit you wish to measure.
~ti2||
 Attach instruments
 Attach {wires:wir} from the terminals of the instrument
icon to points where you want to measure values in
the circuit. Use the {connector} to put test points
in the circuit.
~ti3||
 Adjust and read
 {Zoom Open:zoom} instruments on the {workspace:wksp}
by double clicking them. Now you can read their
displays, {adjust:sps} their controls, or {drag:drg}
their faces around.

 {See each instrument for details.:ilst}
~wksp||
 Workspace
 To build a circuit
      {•  pick components from the parts bin:pnt}
      {•  place them on the workspace:wksp}
      {•  wire the components together:wir}
      {•  attach test instruments:inst}
      {•  select Start Simulation under the:go}
         {EWB menu to activate the circuit:go}

 When an object is {selected:ot} you can {drag:drg} it,
connect {wires:wir} to other objects, or perform
various {edit} operations on it.

 You can {scroll the workspace:scrl} to build a
large circuit.

 {common operations:ops}   {tips}
~tips||
 Tips
 When you lay out a circuit, leave room between
parts to insert connectors or other parts easily.

 {Rotate} parts to get the layout you want.

 You can turn on a {grid} that objects will line up
with. All terminals of all parts will be on grid
lines if you choose grid size 1 -- this eliminates
small kinks in the wires.

 {Wires:wir} may find different routes if they start
from the other end. This can help make a nice
appearance for {printing out:prt}.

 Use {macros:macro} to make parts you don't have, such
as gates with three or more inputs, or to build a
complex circuit out of smaller modules. You must
{save:lsp} the parts bin with the macro and use
the same bin when you reload circuits containing
the macro in the future.
~scrl||
 Scrolling the workspace
 The circuit may be considerably larger than the
area of the screen. The workspace has an area of
approximately three by three screens.

 Use the {scroll:scri} bars at the bottom and at
the right to move the circuit around. Click at an
arrow to move the workspace in the indicated
direction, or drag a scroll box. The scroll
boxes also indicate the relative position of the
visible portion in the workspace. When you move
a wire on the workspace beyond the edge of the
screen, the workspace scrolls to keep up with it.

 The workspace will not scroll when an
instrument face is {zoomed:zoom} open.
~ops||
 Common operations
 Electronics Workbench operates by direct
manipulation of objects on the screen. You can do
all operations in the program without entering
commands. Command (Æ) keys provide shortcuts to
most operations.

 To do anything with an object in Electronics
Workbench, {point:pnt} to it with the mouse.

 Now press the mouse button to {select:sel} the
object and the simplest thing you can do with
the highlighted object happens. For most
objects, this means you can {drag:drg} it with
the mouse.

 The {Edit menu:edit} lets you do things such as
{label}, {rotate}, {cut}, {copy} or make a
{macro} of one or many parts.

 Shortcut: Select an object and use the command
key listed under the {Edit menu:edit} to do most
operations.
~pnt||
 Pointing with the tracker
 Move the tracker onto a component. Press and
hold the mouse button to make the component
move with the mouse and release the button to
leave the component in place on the {workspace:wksp}.

 Connect parts with wires by pointing to a terminal,
pressing the mouse button and stretching the wire
to another terminal to highlight it, and then
releasing the button.
~sel||
 Selecting objects
 Throughout these instructions, we refer to actions
on selected objects. To keep the explanations
simple, "select" may refer to any of the
following actions:
          selecting things {one at a time:ot}
                        or {in a block:bs}.

 You may also {select all:selall} the elements
at once.

Double clicking --
 Clicking the mouse button twice quickly is a
 shortcut for {zooming:zoom} and loading files.
~ot||
 Selecting one at a time
 Point to an object and click the mouse button.
The object highlights to indicate that it is
selected and ready for action. (To deselect,
click the button while not touching any component.)

 You can select several parts by holding down
the SHIFT key. This allows for mass {cutting:cut},
{copying:copy}, {moving:drg}, {rotating:rotate} or
{labeling:label}.

 The mouse button causes an appropriate
action to happen, such as picking up a component,
stretching a wire, or moving a {spin selector:sps}.

 Command (Æ) keys act on a selected object. These
keys perform the same functions as {edit} items.
~bs||
 Selecting in a block
 You can select a group of parts for many
operations -- hold the mouse button and
move the mouse to stretch a rectangle that
selects components in its range. Release the
botton and the parts within the rectangle
will be selected.

 This is useful for {cutting:cut}, {copying:copy}
{moving:drg} and making {macros:macro}. It also
works for {rotating:rotate} and {labeling:label}.
~selall||
 Select All
 Use this option under the {Edit menu:edit} to select
all the workspace elements. This allows for mass
{cutting:cut}, {copying:copy}, {moving:drg}, {rotating:rotate}
or {labeling:label}.
~drg||
 Dragging objects around
 To move a single object, you can {point:pnt} to it
with the tracker and press and hold the mouse
button. Now you can drag the part, instrument
icon, instrument face, or dialog box around on the
{workspace:wksp}.

 To move a selected block, drag one of the
highlighted items. The other objects will also
move.

 Release the button to leave the object(s) in its
new place. Objects may be freely dragged about on
the screen this way.
~wir||
 Wires
     • {Connect:cct} components by selecting a terminal
     and stretching a wire to its destination.

     • To {disconnect:dct} parts, simply select a
     terminal and move the tracker before
     releasing.

     • {To connect wires to each other:wct}, use a
     {connector} from the parts bin.
~cct||
 Connecting parts
 To connect components or instruments with wires,
{point:pnt} to a terminal on the object. When the
terminal is highlighted, press and hold the
mouse button while moving the mouse. A "rubber
band" line appears, with one endpoint attached to
the terminal and the other attached to the tracker.
Move the tracker to highlight the destination
terminal and release the button.

 The wire finds a route between the terminals
automatically, making sure it does not go on top of
other components and does not overlap other wires.
Wires cross at right angles without connecting.

 You can insert components into wires by
aligning their terminals with the wire and
releasing.
~wct||
 Joining wires
 A {simple junction:connector} is included in the
parts bin. Use it to:

        • make direct connection between wires
        • attach test {instruments:inst}

 Like all other circuit elements, in order to
have values, these connectors must be in a
circuit before it is analyzed with
{Start Simulation:GO}. Put connections along
the wires in your circuit for test points
while you build it.

 If you {rotate} or move a component that
is already wired in place in the circuit, the
wires automatically connect to the new position.
Moving a component, even accidentally, does not
undo prior work.
~dct||
 Cutting wires
 Remove components or instruments from the
{workspace:wksp} by {dragging:drg} them to the parts
bin or top shelf areas. Disconnect wires by
selecting a terminal, holding the mouse
button, and releasing away from any terminal.
~bin||
 Parts bin
 The parts bin contains the {supply of parts:com}.

 You can {label} components in the parts bin, so
you can put many components of the same value into
the circuit easily. You can change the value in
the parts bin without affecting parts already on
the {workspace:wksp}. {Cut} parts from the bin
by {selecting:sel} them with the tracker and
typing ÆX.

 If you {cut} parts from the bin or add
{macros:macro} to it, be sure to save the new parts
bin under a new name.
~go||
 Activating the circuit
 Start Simulation under the EWB menu is
used to simulate the activity of the circuit.

  {• simulation:sim}     {• errors:err}
~sps||
 Spin selector
 Many of the controls on the instruments are spin
selectors. A box containing a number highlights
when you point to it. Press and hold the mouse
button to change the number through a range of
values by moving the mouse. Release the button on
the desired number to set the value.
~keys||
 Special keys and editing
 {File} boxes, {label} boxes,
the {word generator} and the {truth table}
have text fields you can type into.

 On the boxes, a text cursor appears at the
beginning of the first line.

 On the instruments, you must activate the text
cursor by {pointing:pnt} to the text field and
clicking.

 {The editing keys:ky1} that move the cursor and
edit the text work as expected in a text field.
~ky1||
 Editing keys
 The cursor control keys move left and right,
and up and down if appropriate. RETURN acts as
clicking ACCEPT would. TAB moves forward through
the fields if there are more than one.
~ctrl||
 Program controls
 The menu bar at the top of the screen controls
fundamental operations in the program:

      {File}   {Edit}   {EWB}

 The three {scroll bars:scri} control the {parts bin:bin}
and {workspace:wksp}.

 Towards the middle of the instrument shelf, the
filename for the circuit is displayed. When you
load a circuit, the filename appears here.
~scri||
 Scroll bars
 The scroll bars allow you to move the
{parts bin:bin} (bar on the far left)
or the {workspace:wksp}.

 Point to an arrow and click to move the area
in the indicated direction. Alternatively,
{drag:drg} the box inside to scroll the area.
~file||
 File Menu operations:
{New -- ÆN:new}
{Open Circuit -- ÆO:lsc}
{Open Library:lsp}

{Save Circuit -- ÆS:lsc}
{Save Circuit As:lsc}
{Save Library:lsp}
{Save Library As:lsp}

{Page Setup:pgset}
{Print:prt}
{Quit}
~edit||
 Edit Menu operations:
{Undo -- ÆZ}

{Cut -- ÆX:cut}
{Copy -- ÆC:copy}
{Paste -- ÆV:paste}
{Clear:clr}

{Duplicate:dup}
{Select All:selall}

{Label -- ÆL:label}
{Rotate -- ÆR:rotate}
{Define Macro -- ÆM:macro}
{Zoom Face:zoom}
~ewb|emen||
 EWB Menu operations:
{Help -- ÆH:help}
{Preferences:pref}
{Start Simulation:go}
~help||
 Help -- ÆH
 Type ÆH or choose Help from the {EWB menu:emen}
to get help with Electronics Workbench.

 If an object is selected when help is
called, it will refer to the selected object. If
help is called with no object selected, a list of
topics is presented. Click on an entry and a window
containing information will open.

 Within the help system, boldface marks
cross-references to other topics. You can select
these words to open another window on the new
topic. More than one help window may be open at
once. You can move the windows around on the
{workspace:wksp} and the workspace is usable while
the windows are open.
~undo||
 Undo -- ÆZ
 Use this feature to undo any {cutting:cut},
{copying:copy}, or {pasting:paste}.
~cut||
 Cut -- ÆX
 Cut parts that are {selected:sel} from the
{workspace:wksp} with the {Edit menu:edit}
or ÆX. This is useful for removing
several parts at once from the circuit.

 The cut parts are placed in the {clipboard}
so that you may {copy} them.

 If a part is inadvertantly cut, you may
{undo} the cut.

 You can {drag:drg} individual parts back to the
{parts bin:bin} and release them; they need not be
disconnected beforehand.
~copy||
 Copy -- ÆC
 To copy a part on the {workspace:wksp} to the
{clipboard}, {select:sel} it and choose Copy from
Edit or type ÆC. You may then {paste} one or more
copies of this part onto the workspace.

 Copies of parts have the same {labels and:label}
{values:label} as the original, so you can make many
copies with the same value easily by assigning a
value before copying and pasting. Groups of parts
may be selected and copied to other places in the
circuit.

 You can make direct copies of parts, bypassing
the {clipboard}, by {duplicateing:dup} them.
~dup||
 Duplicate
 To directly copy a part on the {workspace:wksp} to
another place, {select:sel} it and choose Duplicate
from Edit.

 Duplicates of parts have the same {labels and:label}
{values:label} as the original, so you can make many
duplicates with the same value easily by assigning
a value before duplicating. Groups of parts may be
selected and copied to other places in the circuit.
~paste||
 Paste -- ÆV
 Use this feature to place parts {copied:copy} or
{cut} from the workspace back onto the workspace.
Multiple copies of the same object(s) may be made
by repeatedly pressing ÆV.
~clr||
 Clear
 This feature removes any selected part(s)
from the workspace without copying the
part(s) into the {clipboard}. Use {cut}
to remove parts into the clipboard.
~clipboard||
 Clipboard
 The clipboard holds any parts {cut} or
{copied:copy} from the workspace. The part(s)
may then be {pasted:paste} back onto the workspace.
~macro||
 Macro -- ÆM
 You can combine circuits or sub-circuits
into a macro block.

 You can make new parts, such as logic gates with
more inputs, or develop large circuits with
smaller modules.

{select parts:mc1}  {edit macros:mc2}  {save parts:mc3}
~mc1||
 Making a macro
 {Select:bs} the components you want on the
{workspace:wksp} and choose Macro from the {Edit menu:edit}.
You should give it a name and you must decide
whether to copy the parts or move them from the
workspace into the macro. The macro is then
automatically placed into the {parts bin:bin} in a
standard package.
~mc2||
 Editing a macro
 You can edit the contents of the macro by
{zooming:zoom} it open on the workspace. Stretch
wires to the sides of the box to make terminals.
Macros can have labels, which are displayed on the
icon.
~mc3||
 Save macros
 To use macros in a future session, you must {save:lsp}
{the parts bin:lsp} containing them and reload it when
the circuit is used again. Macros that are not in
the current parts bin will be empty and not run.
~label||
 Label -- ÆL
 Use this
        • to {give values:gvl} to analog parts
        • to {label parts:lbp}
        • to {label the circuit:lbp}
        • to {define models:dfm} of analog parts

 Type values into the "Value" text field.
Not all components will have value text fields.

 Type labels into the "Label" text field.

 Choose models with the "Model" {spin selector:sps}.

 Click on the "Model" button to {alter analog models:dfm}.

 Analog parts must have values for the circuit
simulation to work. Most parts do not have
default values, though the transistors and
diodes have typical useful values.

 To {show:slb} labels, values and models on
the workspace, use the {Preferences:pref} menu.

 You can {select a block:bs} of components and then
label them sequentially by choosing Label,
assigning values or labels in turn, and canceling
the operation when desired or finished.
~gvl||
 Analog values
 Give values to components by {selecting:sel} them
and choosing Label from the {Edit menu:edit} or
typing ÆL. Enter the desired input into the
appropriate boxes from the keyboard. If you click
ACCEPT without entering values, the minimum
acceptable value will be given to the part.
Labels and values can be given to parts in the
circuit or in the {parts bin:bin}.

 To change the values of some parts such as the
transistor, you must click on the {"Model" box:dfm}
and adjust parameters appropriately.

 You can give values to the components in the parts
bin, so that many parts with the same value can be
used. Changing the value of the part in the bin
does not change values already in the circuit.
~lbp||
 Text labels
 You can put labels up to eight characters long
on components, including connectors.

 You can give a label to the entire circuit by
selecting Label or ÆL with no parts selected.

 The circuit label will be {printed:prt} out with
the circuit. It is placed beside the schematic on
the printed output.
~dfm||
 Analog models
 Clicking on the "Model" button opens a box
containing the component parameters. Type the
desired value in the text field beside the
standard abbreviation. The parameters for each
part are explained in the User Manual.

 Models are global, so you can change values for
a model and the changes affect every copy of that
model in the circuit. Models are saved with the
parts bin.

 The "Model" {spin selector:sps} displays the list
of available models.

 Next to "New name" is a text field in which
either a new name for the existing model, or the
name of a new model can be entered.

 In order to change the name of the displayed
model, without generating a new model, specify
the desired name in the "New name" text field
and click on "Change name".

 If a new name is specified, "Save changes" will
generate a model with this new name, having the
specified parameters.

 If no new name is specified, "Save changes" will
save the new model parameters for the existing
model.

 If a model is no longer useful and you wish
to remove it from the list of available models,
click on "Delete".

 While the model box remains active, you can
edit, add or delete as many models from the
model list as you wish.

 When you have completed your edits, and you
have located the model which you wish to assign
to the part being labeled, click on "Accept".
It is not necessary to click on "Save changes"
first, as this is automatically done.

 If you have performed edits, but do not wish
to change the model of the part being labeled,
click on "Cancel".
~zoom||
 Zoom Face
 Zoom works on {instruments:inst} or {macros:macro}.
{Select:sel} the instrument or macro and choose
Zoom Face from {edit} to show an enlarged view. To
close the instrument or macro, do the same thing.

 Shortcut:  double click the mouse button to open
            click on the upper-left box to close
~rotate||
 Rotate -- ÆR
 You can rotate most of the components to achieve
nearly any desired layout on the {workspace:wksp}.
Each time you select a part and rotate it, it
turns 90 degrees clockwise. {Select:sel} a part or
parts and choose Rotate from the {Edit menu:edit} or
type ÆR.

 Note: the {ground} symbol does not rotate.

 Transistors rotate 90 degrees the first time
you select Rotate, then reverse their symmetry for
the remaining two positions. This enables you to
follow standard drafting conventions when laying
out a circuit.
~lsc||
 Loading and saving circuits
 When you choose to load or save a circuit from the
file menu, you get a list of existing circuits.

     • To save a new circuit, type a name into
     the lower empty box and click on SAVE.

     • To load a circuit file, select a name from
     the scrolling list or type the name in the
     lower box and click on LOAD.

RETURN after typing is a shortcut to SAVE.
Double click on the file in the list to LOAD.

Tip: Save the circuit with the test instruments
wired in place and the settings of the instruments
will be saved too.
~lsp||
 Loading and saving the library (parts bin)
 Special parts files are useful to collect special
{macro} circuit components or to control
{values:label} of parts for teaching assignments.

 When you choose to load or save a parts bin
from the file selector box, a list of existing
bins appears.

     • To save a new parts bin, type a
     name into the lower empty box and
     click on SAVE.

     • To load a parts bin, select a name
     from the scrolling list or type the name
     in the lower box and click on LOAD.

BE CAREFUL NOT TO SAVE A PARTS BIN OVER A DIFFERENT
ONE WITH THE SAME NAME. THE NAME OF THE BIN IS
DISPLAYED ON THE DIALOG BOX. YOU WILL BE WARNED IF
THE FILE EXISTS. IF YOU DO NOT SAVE THE PARTS BIN,
THE CIRCUIT WILL STILL LOAD, BUT SOME PARTS MAY NOT
WORK.

 When you save a circuit, the name of the parts bin
loaded at the time is saved with the circuit.  This
same bin will automatically load with the circuit.

RETURN after typing is a shortcut to SAVE.
Double click on the file in the list to LOAD.
~grid||
 Grid
 Using the {Preferences:pref} menu, you
can turn on a gridsnap feature that
causes components to align themselves
automatically.

 You can turn the display of the grid on
or off when it is active.

 Only at the smallest grid size will all
terminals on all objects align to grid
points.
~sgr||
 Show grid
 When the {grid} is turned on, you can display it
if you want by clicking on the button on the
{Preferences:pref} menu.
~slb||
 Show labels
 From the {Preferences:pref} menu,
set this on to display {labels:label}
assigned to parts.
~svl||
 Show values
 From the {Preferences:pref} window
set this on to display {values:label}
assigned to parts.
~new||
 New
 From the {File menu:file}, select this to clear the
{workspace:wksp}, the circuit name, and the
readings on instruments. A dialog box asking
confirmation of the action will appear.
~pgset||
 Page Setup
 From the {File menu: file}, select this to control
the quality of print, the paper size, and the
output orientation.
~prt||
 Print
 Select Print from the {File menu:file} to get the
circuit printed. A menu of options will appear to
print:
   •   the circuit
   •   the faces of the {test instruments:inst},
   •   and the parts list.

 You can {make a label:label} for the circuit using
Label from the {Edit menu:edit} or by typing ÆL when
nothing else is selected. It is a free-form {text:keys}
{field:keys} of six lines by twenty-five
characters.

 The basic features of the IBM graphics and Epson
printers are used, making the output compatible
with many printers.
~quit||
 Quit
 Selecting Quit from the {File menu:file} exits
the program and returns to the
operating system. A confirmation box
appears.
~connector||
 Connector
 Use a connector to {join two wires:wct}. Otherwise,
wires cross without electrical connection.

 It is good practice to place connectors into a
circuit at various test points before
{simulation:sim} so you can make readings at
various places in the circuit.
~ground||
 Ground
 Ground is the reference point for relating
electric {voltage:v} levels wherever electricity is
used. The ground symbol from the {parts bin:bin}
provides this reference.

 In digital {simulation:sim}, ground is used for a 0
level.

 Analog circuits require a common ground to work
properly and give consistent results. Be especially
careful to have both sides of a transformer grounded.

 It is important to ground analog instruments to
obtain accurate results.

 The analog simulation will give an error message
if the circuit and instruments are not properly
grounded.

 {More information about ground:mrgn} is available.
~mrgn||
 Ground -- general information
 A voltage measurement is always referenced to some
point, since a voltage is actually a "potential
difference" between two points in a circuit.

 The concept of "ground" is a way of defining a
point common to all voltages, one which we agree
represents the common reference for all the
circuits. It represents "0 Volts"; all voltage
levels around the circuit are positive or negative
when compared to that reference point. In power
systems, the planet Earth itself is used for this
reference point (most home power circuits are
ultimately "grounded" to the Earth's surface for
lightning protection). This is how the expression
"earthing" or "grounding" a circuit originated.

 Most modern power supplies have "floating" +/-
outputs, and either output point can be defined as
ground. These types of supplies can be used as
positive (with respect to ground) or negative
power supplies. In floating power supply circuits,
the positive output is often used as the voltage
reference for all parts of the circuit.
~tpx||
 Topics available
{ac voltage}
{ammeter}
{analog circuit simulation:sim}
{analog components:com}
{analog error conditions:err}
{analog instruments:ilst}
{analog precision:apre}
{battery}
{Bode plotter}
{bulb}
{capacitor}
{clear:clr}
{common operations:ops}
{components:com}
{connector}
{copy -- ÆC:copy}
{current source:ctsc}
{cut -- ÆX:cut}
{diode}
{dragging:drg}
{duplicate:dup}
{edit menu:edit}
{EWB menu:emen}
{file menu:file}
{function generator}
{fuse}
{grid}
{ground}
{help -- ÆH:help}
{inductor}
{label -- ÆL:label}
{light-emitting diode:led}
{macro -- ÆM:macro}
{multimeter}
{new}
{opamp}
{oscilloscope}
{page setup:pgset}
{parts bin:bin}
{paste}
{pointing:pnt}
{preferences:pref}
{print:prt}
{program controls:ctrl}
{quit}
{relay}
{resistor}
{rotate -- ÆR:rotate}
{scrolling/scroll boxes:scrl}
{selecting:sel}
{select all:selall}
{show grid:sgr}
{show labels:slb}
{show values:svl}
{special keys:keys}
{spin selector:sps}
{start simulation:go}
{steady state analysis:tsa}
{summary of analog simulation:sas}
{test instruments:inst}
{text fields:keys}
{tips}
{transformer}
{transient analysis:tsa}
{transient/steady state:tsa}
{transistor:xstr}
{undo -- ÆZ:undo}
{useful formulas:crib}
{voltage sources:v}
{voltmeter}
{wiring:wir}
{workspace:wksp}
{zoom face:zoom}
~pref||
 Preferences
{transient/steady state:tsa}
{analog precision:apre}
{grid}
{show grid:sgr}
{show labels:slb}
{show values:svl}
~tsa||
 Transient/Steady State
 This controls the kind of analysis done and the
display of the waveform on the {oscilloscope}.

   {transient:tra}    {steady state:ssa}
~tra||
Transient analysis
 Displays the initial response of the circuit and
stops the trace when the oscilloscope screen
fills. If a steady state is achieved before the
scope screen is filled, the steady-state waveform
will continue to fill it. In this mode,
redisplaying the scope will show only the first
cycle of the transient response.
~ssa||
 Steady state analysis
 Analysis continues until a steady state is
reached. The scope redraws each time the screen is
full. Some circuits may take many cycles to reach
stability. If you wish to observe a lengthy
transient response, select Steady State (even
though you cannot save and redisplay the
transient).
~apre||
 Analog precision
 You can control the degree of accuracy used to
compute the values of the {analog simulation:sim}
with the {spin selector:sps} on the
{Preferences:pref} menu.

  Requiring less accuracy can speed up circuit
simulation. The smaller the percentage of
precision, the more accuracy will be computed. The
program defaults to the least precision and
greatest speed.
~sim||
 Simulating analog circuits
 {• summary of simulation:sas}
 {• error conditions:err}

 After you build a circuit, you can test it by
simulating its activity. Electronics Workbench
solves a set of equations to find all the current,
voltage and resistance values in the circuit at
many points over an interval of time. The test
instruments let you {read the values:sm1}.

 Use the {Preferences:pref} menu to choose between:

         {• transient analysis:tra}
         {• steady state analysis:ssa}

The analysis chosen affects the operation of the
{oscilloscope}.

 When anything in the circuit is changed
(components removed or inserted, values of
components changed, settings on the function
generator changed) the analysis is no longer valid.
~sm1||
 Reading test points
 After simulation is complete, the {instruments:ilst}
will display the values and waveforms of the
signal at any node in the circuit. As long as the
simulation is valid, that is, as long as the
circuit has not changed, the wires from the
{oscilloscope} and the {multimeter} may be moved
to any connection point on the circuit to display
the values.

 The oscilloscope redraws itself whenever its
probes are moved; it displays present values at
all nodes in the circuit without having to select
{Start Simulation:go} again.

 It is good practice to insert {connectors:connector}
in wires at various points in your circuit so you
can read values there.

 The old values remain at each node in the circuit
even after changes are made in the circuit, so if
you accidentally clip a wire and restore it, the
values can still be read. (This feature is provided
because the mathematics of simulating a circuit can
take a long time, especially with a complex
circuit.)

 You can change the controls on the oscilloscope to
display the waveform at a different scale without
resimulating. Just click on AC/0/DC on either
channel to draw at the new settings.

 Remember to select {Start Simulation:go} whenever
anything in the circuit is changed or the input
to the circuit from the {function generator} is
changed.
~err||
 Analog error conditions
 If the circuit is improperly constructed, it
will not function and no mathematical
{simulation:sim} is possible. When this
happens, a confirmation box gives an error
message that may help you find the problem.

 You must determine by inspection the cause of
the failure.

 Sometimes there is not enough memory to
complete the operation.
~sas||
 Summary of analog simulation
 Analog simulation always requires {Start:go}
{Simulation:go} to simulate the circuit.

 The values remain in place at the nodes of the
circuit and remain true for that configuration.

 To see the effect of changes in the circuit, you
must select Start Simulation again.

     {• details:sim}  {• errors:err}
~com||
 Analog components
{ac current}
{ac voltage}
{ammeter}
{battery}
{bulb}
{capacitor}
{connector}
{current sources:ctsc}
{dc current}
{diode}
{fuse}
{ground}
{inductor}
{led}
{operational amplifier:opamp}
{relay}
{resistor}
{transformer}
{transistors:xstr}
{voltage sources:v}
{voltmeter}
{zener diode}
~bulb||
 Bulb
 The light bulb is a {resistive:r}
component that dissipates energy
in the form of light. Specify its
power rating in watts.
~fuse||
 Fuse
 This {resistive:r} component serves to
protect against power surges and
overloads in circuitry. If the {current:mrcs}
exceeds the specified maximum (Imx, in
Amps) the fuse will open ("blow") and
cut off the current flow.
~relay||
 Relay
 The magnetic relay is a {coil:mrin} with a
specified inductance (Lc, in Henries) that
will cause a contact to open or close when a
specified {current:mrcs} (Ion, in A) charges it.
The contact will remain in the same position
until the current falls below the holding
value (Ihd, in A), when the contact will
return to its original position.
~ac current||
 AC current source
 The alternating {current source:ctsc} in the
analog {parts bin:bin} may be adjusted to any
{value:label}. The number is the RMS value of
the signal.

 Set its frequency on the {function generator}.
~ac voltage||
 AC voltage source
 The alternating current {voltage source:v}
in the analog parts bin may be adjusted to
any {value:label}. The number is the RMS value
of the signal.

 Set its frequency on the {function generator}.
~ammeter||
 Ammeter
 The ammeter in the parts bin allows you to
measure {current:mrcs} flow within the circuit.
Insert meters in the circuit (in series
with the flow being measured) wherever you
wish a reading. You can use as many meters
as you wish.

 The internal resistance is controlled by
the setting of the {multimeter} using {value:label}.
~battery||
 Battery
 The battery serves as a d.c. {voltage source:v} that
is completely {adjustable:label} in this program.
      {more about batteries:mrbt}.
~mrbt||
 Batteries -- background information
 A battery is a single electrochemical cell, or a
number of electrochemical cells wired in series,
used to provide a direct source of {voltage:v}
and/or {current:ctsc}.

 The single cell has an approximate voltage of 1.5
Volts, depending on its construction. It consists
of a container of acid in which an electrode is
placed. Chemical action causes electrons to flow
between the electrode and the container, and this
creates a potential difference between the
electrode and the material of the container.

 Batteries can be rechargeable, and can be built to
deliver extremely high currents for long periods.
The automobile ignition battery is an application
of a battery as a "current source"; the voltage
may vary considerably under use, with no visible
battery deterioration.

 Batteries may be used as voltage references, their
voltage remaining stable and predictable to many
figures of accuracy for many years. The standard
cell is such an application. A standard cell is a
voltage source, and it is important that current
is not drawn from the standard cell.
~capacitor|c||
 Capacitor
 The {value:label} of a capacitor may be adjusted
as desired.

 A capacitor stores electric energy, affecting
a.c. relative to capacitance and a.c. frequency
and d.c. depending on capacitance alone.

       {more about capacitors:mrcp}
~mrcp||
 Capacitors -- background
 Capacitors in an a.c. circuit behave as "short
circuits" to a.c. signals. They are widely used to
filter or remove a.c. signals from a variety of
circuits--a.c. ripple in d.c. power supplies, a.c.
noise from computer circuits, etc.

 Capacitors prevent the flow of direct {current:ctsc}
in a d.c. circuit. They can be used to block
the flow of d.c., while allowing a.c. signals
to pass. Using capacitors to couple one circuit
to another is a common practice.

 Capacitors take a predictable time to charge
and discharge and can be used in a variety of
time-delay circuits. They are in some ways
similar to {inductors:inductor} and are often
used with them for this purpose.

 The basic construction of all capacitors involves
two metal plates separated by an insulator.
Electric current cannot flow through the
insulator, so more electrons pile up on one plate
than the other. The result is a difference in
{voltage:v} level from one plate to the other.
~ctsc||
 Current source
 Sources of a.c. and d.c. current are provided in
the {parts bin:bin}. Their values may be adjusted by
selecting {label} from the {Edit menu:edit}, or by
typing ÆL.

    {more about current sources:mrcs}

 Current is calculated as follows:

              I
        E = 
              R

~mrcs||
 Current -- background
 Alternating or direct current comes from a power
supply to a load, where the output {voltage:v} of
the supply is not important (and may, in fact, be
very low).

 Most modern d.c. power supplies, using electronic
control of the output level, can be used as either
{voltage sources:v} or current sources. When the
load on the power supply becomes very heavy (a
small load resistance) these supplies will switch
from a voltage supply to a current supply.

 Bipolar {transistors:xstr} are current-based. They
can be treated as low impedance current sources
for circuit analysis purposes.

 Current sources are often used as signal sources
during the analysis of electric networks if there
is more concern about the currents flowing into
and out of a point than about the voltage
appearing across a component.

 In general, current sources are associated with
low impedance circuits, while voltage sources are
associated with high impedance circuits.
~dc current||
 DC current source
 The direct {current source:ctsc} may be adjusted to any
value by using {Label} from the {Edit menu:edit} or ÆL.
   {more about current sources:ctsc}
~diode|di||
 Diode
 A supply of general purpose diodes is
included in the {parts bin:bin}. You can
adjust the {value:label} of several parameters
to change the characteristics of the device.

          {more about diodes:mrdi}
~mrdi||
 Diodes -- background
 A diode is the simplest form of solid state
switch, being either open (not conducting), or
closed (conducting).

These solid state components conduct electric
{current:ctsc} very easily in one direction, while
conducting current very poorly in the opposite
direction.

 Diodes exhibit a number of useful characteristics,
such as predictable capacitance (that can be
{voltage:v} controlled) and a region of very stable
voltage. Diodes can, therefore, be used as voltage
controlled {capacitors:c} (varactors) and voltage
references (zener diodes).

 Because diodes will conduct current easily in only
one direction, they are used extensively as power
rectifiers, converting a.c. signals to pulsating
d.c. signals, for both power applications and
radio receivers.

 Diodes behave as voltage controlled switches, and
have replaced mechanical switches and relays in
many applications where remote signal switching is
done.

 Even indicator lamps are now replaced with diodes
({LEDs:led}) that emit light in a variety of colors
when conducting.

 A special form of diode, called a {zener diode},
is useful for voltage regulation.
~led||
 Light-Emitting Diode
 The Light-Emitting {Diode} emits visible
light when conducting {current:ctsc} in
the "forward" direction (current exceeds
Ion in Amps).

 An LED is available in the digital {parts bin:bin}
for use as a probe. For this operation it requires
no external load {resistor} or ground connection,
though practical circuits must supply them.

 {more about LEDs:ledinf}
~ledinf||
 LED general information
 LEDs are constructed of Gallium Arsenide or
Gallium Arsenide Phosphide. While efficiency can
be obtained when conducting as little as 2
milliAmperes of current, the usual design goal
is in the vicinity of 10 mA. During conduction,
there is a {voltage:v} drop across the diode of
about 2 volts.

 Most early information display devices required
power supplies in excess of 100 volts. The LED
ushered in an era of information display components
with sizes and operating voltages compatible with
solid state electronics. Until the low-power
Liquid-Crystal Display was developed, LED displays
were common, despite high current demands, in
battery-powered instruments, calculators, and
watches. They are still commonly used as on-board
annunciators, displays, and solid state indicator
lamps.
~zener diode||
 Zener diode
 Zener diodes are special diodes designed to
continue operation within the reverse breakdown
area, beyond the Peak Inverse Voltage rating of
normal diodes. For zener diodes, this reverse
breakdown voltage is called the zener voltage
(VÊ), which can range between 2.4 V and 200 V.

 Zener diodes are used primarily in circuits
for voltage regulation.

          {more about diodes:mrdi}
~inductor||
 Inductor
 The {value:label} of an inductor may be set as
necessary.
 {more about inductors:mrin}
~mrin||
 Inductors -- background information
 A coil of wire, of one "turn" or more, an inductor
stores energy in an electromagnetic field.
Inductors develop an electromagnetic field when
{current:ctsc} through them changes. Inductors
react to being placed in a changing magnetic field
by developing an "induced" {voltage:v} across the
turns of the inductance, and will provide current
to a load across the inductance. Voltages can be
very large.

 Inductors are similar to {capacitors:c} in storing
energy in electric fields, and their "charge" and
"discharge" times make them useful in time delay
circuits.

 Electric transformers take advantage of the
transfer of energy in a magnetic field from the
primary winding to the secondary winding, using
induced voltage and current. The transfer is
proportional to the ratio of the winding turns.

 Radio antennae are inductors, and operate exactly
like transformers in generating electromagnetic
fields and in detecting them. Efficiency is
proportional to size.

 The ignition coil in an automobile develops a very
high induced voltage when the current through it
suddenly becomes very great. This is the voltage
that fires spark plugs.
~opamp||
 Operational amplifier
 A supply of operational amplifiers is
included in the {parts bin:bin}. You can
adjust the {value:label} of several parameters
to change the characteristics of the device.

          {more about opamps:mrop}
~mrop||
 Opamps -- general
 The operational amplifier is a high gain
block based upon the principle of a
differential amplifier. It is common to
applications dealing with very small input
signals.

 The open loop gain (A) is typically very
large (10e5 to 10e6). Applying a
differential input across the opamp
terminals (+, -), the output voltage will
be: v·„‚ = A * (v+ - v-).

 The differential input must be kept small,
since the opamp saturates for larger
signals. The output voltage will not exceed
the value of the positive and negative power
supplies (Vp), also called the rails, which
vary typically from ±5V to ±15V. This
property is often used in alarm systems, to
trigger an alarm when a signal exceeds a
certain value (called a Schmitt trigger).

 The operational amplifier is also used in
feedback circuits. With the correct
combination of resistors, both inverting and
non-inverting amplifiers of any desired gain
can be constructed.

 Other properties of the opamp include a high
input resistance (Ri), and a very small
output resistance (Ro). Large input
resistance is important so that the opamp
does not place a load on the input signal
source. Due to this characteristic, opamps
are often used as front-end buffers to
isolate circuitry from critical signal
sources.

 In analyzing circuits containing operational
amplifiers, it is best to assume all
amplifiers are ideal. The six
characteristics of an ideal amplifier
include:
   1. infinite open loop gain (A)
   2. infinite input resistance (Ri)
   3. zero output resistance (Ro)
   4. infinite bandwidth
   5. differential input voltage of zero,
      i.e. v+ = v-
   6. zero current flow into either input
      terminal.
~resistor||
 Resistor
 The {value:label} of a resistor may be adjusted as
desired.
   {about resistance and Ohm's law:r}
   {more about resistors:mrr}.
~r||
 Resistance
 Ohm's Law states that {current:ctsc} flow depends on
circuit resistance:

                 I = E/R


 Circuit resistance can be calculated from the
current flow and the {voltage:v}:

                 R = E/I.


 Circuit resistance can be increased by connecting
resistors in series:

        R‚ = R– + R— +...+ R‡


 Circuit resistance can be reduced by placing one
resistor in parallel with another:

                     1
        R‚ = 
               1     1     1
               +  + 
               R–    R—    R‡


 Resistors come in a variety of sizes, related to
the power they can safely dissipate. This can be
calculated:

        P = I◊R


   {more about resistors:mrr}
~mrr||
 Resistors -- general information
 Color coded stripes on the resistor body specify
resistance, and the tolerance of resistance
accuracy. Larger resistors have these
specifications printed on them.

 Any electrical wire has resistance, depending on
its material, diameter, and length. Wires that
must conduct very heavy currents ({ground} wires
on lightning rods, for example) have large
diameters, to reduce resistance.

 The power dissipated by a resistive circuit
carrying electric current is in the form of
heat. Circuits dissipating excessive energy
will literally burn up. Practical circuits
must take power capacity into account.
~transformer||
 Transformer
 You can adjust the model parameters of the
transformer using {label}.

 For the simulation to work properly, both
sides of the transformer must have a common
reference point, which may be ground.

 Transformers are one of the most common and
useful applications of {inductance:mrin}.
~npn bjt||
 NPN transistor
 The NPN bipolar transistor has generic
values suitable for most circuits. These
values may be changed by clicking on Modify
Parameters from the {label} box.
    {more about transistors:xstr}
~pnp bjt||
 PNP transistor
 The PNP bipolar transistor has generic
values suitable for most circuits. These
values may be changed by clicking on Modify
Parameters from the {label} box.
    {more about transistors:xstr}
~xstr||
 Transistors
 Bipolar transistors are current-based valves used
for controlling electronic {currents:ctsc}. They are
made from silicon or germanium, with some
"impurity" materials added to facilitate current
flow.

 Bipolars come in two versions: {PNP:pnp bjt} and {NPN:npn bjt}.
They have different power supply polarities and
different internal current flow directions. The
letters refer to the polarities (Positive/Negative)
of the materials making up the transistor
"sandwich."

 Transistors are operated in three different
configurations depending on which element is
common to input and output: common base, common
emitter and common collector. The three modes have
different input and output impedances, different
gains and offer individual advantages to the
designer.

 The transistor began the solid state phase of
electronics, and they still play an important part
in it. Their small size made "chip" technology
possible; even small ICs may contain many
transistors. Transistors make {battery} power
practical for instruments and communicators,
allowing very complex systems to be made light and
portable.
~v||
 Voltage source
 A power or signal source where the chief concern
is the output voltage.

 D.c. power sources must supply voltage with good
"regulation"--freedom from voltage drop with
changes in load or line, and freedom from noise
and a.c. ripple in the voltage output.

 An a.c. voltage source, as a power source or as a
signal generator, must provide a waveform free of
distortion--the waveform must contain only the
fundamental frequency of the a.c. generator, and
no multiple frequencies, called "harmonics".

 If a voltage source is used as a variable-
frequency signal generator, its output impedance
must remain constant as the frequency varies in
order to avoid a varying output voltage. In many
voltage signal sources, it is also important
that the output frequency remain highly stable.

 A voltage source is often used in the analysis of
electric networks, if the emphasis is on voltages
appearing across components, rather than on
{current:ctsc} flowing into and out of points in the
circuit.
~voltmeter||
 Voltmeter
 The voltmeter in the parts bin allows you to
measure {voltage:v} differences between
points in the circuit. Insert meters in the
circuit (in parallel with the points being
measured) wherever you wish a reading. You
can use as many meters as you wish.

 The internal resistance is controlled by
the setting of the {multimeter} using {label}.
~ilst||
 Analog instruments
{function generator}
{multimeter}
{oscilloscope}
{Bode plotter}
~multimeter||
 Multimeter
 Use the multimeter to measure electrical signals
and components to determine {voltage:v},
{current:ctsc} or {resistance:r} between two
points in the circuit.

{general info:inst}    {adjusting the controls:ajm}
~ajm||
 Multimeter controls
   {AMP:mm1} {VOLT:mm2} {OHM:mm3} {dB:mm4}

       {AC:mm5}        {DC:mm6}

       {-:mm7}         {+:mm8}
~mm1||
 AMP -- multimeter
 Displays the {current:ctsc} through the circuit
at the test point. The instrument must be inserted
into the circuit to measure current flow. Note
that it is not possible to switch from measuring
voltage across points of the circuit to measuring
current in the circuit without connecting the
multimeter appropriately, clicking the AMP button,
and clicking {Start Simulation:go} to activate the new
configuration.
~mm2||
 VOLT -- multimeter
 Measures the {voltage:v} difference between any
two points in the circuit. After the circuit has
been simulated, the points of connection may be
moved around to test values at any node in the
circuit.
~mm3||
 OHM -- multimeter
 Measures {resistance:r} between the points of
connection. Note that a part cannot be in a closed
circuit to get an accurate measurement. Total
resistance between points in a resistive network
may be measured.
~mm4||
 dB -- multimeter
 Measures potential difference between two points
in the circuit and displays it as decibels of
loss.
~mm5||
 AC [sine wave symbol] --
 This button causes the meter to display root mean
square values of an alternating signal.
~mm6||
 DC [straight line symbol] --
 This button causes the meter to display the
instantaneous direct current value of a signal.
~mm7||
 "-" -- multimeter
 The negative terminal.
~mm8||
 "+" -- multimeter
 The positive terminal.
~function generator||
 Function generator
 The function generator is a {voltage source:v} that
supplies analog signals in the form of sine, square
and triangular waves.

{general info:inst}     {adjusting the controls:ajf}
~ajf||
 Function generator controls
         {waveform:fg1}

         {frequency:fg2}
         {duty cycle:fg3}
         {symmetry:fg4}
         {amplitude:fg5}
         {offset:fg9}

   {+:fg6}     {COM:fg7}     {-:fg8}


   {spin selectors:sps}   {text fields:keys}
~fg1||
 Waveform -- function generator
 Click on the sine wave, the triangular wave, or
the square wave to control the output waveform.
~fg2||
 Frequency -- function generator
 The frequency value can be {spin selected:sps} from
1 to 999 and the units can spin from Hz to MHz.
~fg3||
 Duty cycle -- function generator
 Duty cycle can spin from 1 to 99 percent and
affects the shape of the square and triangular
waves. For square waves this controls the
proportion of the cycle that is high. 50% duty
gives square waves with high and low parts equal.

 For triangular waves this controls the slope by
shifting where in the cycle the peak is. 50% duty
gives triangular waves with equal slope for the
rise and fall.
~fg4||
 Symmetry -- function generator
 Symmetry controls the amount of signal generated
above and below the d.c. level of the signal.
Values range from 0 to 100%, where 50% provides
rms symmetry about the d.c. level (i.e. positive
and negative peaks are the same distance from the
offset).
~fg5||
 Amplitude -- function generator
 Amplitude controls the value of the wave from its
d.c. level to its peak value. This is the same as
the difference between the COM and + or -
terminals. If the output leads are connected to
COM and to + or -, the peak to peak measurement of
the wave equals twice the amplitude value. If the
output comes from + and -, the peak-to-peak value
will be four times the amplitude value. Offset
controls the d.c. level about which the
alternating signal varies.

 The units value for Amplitude applies to the
offset as well.

 Note that the Amplitude is a peak reading,
while the values of the alternating sources
in the parts bin are RMS values.
~fg6||
 "+" -- function generator
 Provides a signal with the selected amplitude in
the positive direction from neutral COM.
~fg7||
 COM -- function generator
 Provides a reference level signal.
~fg8||
 "-" -- function generator
 Provides a signal with the selected amplitude in
the negative direction from neutral COM.
~fg9||
 Offset -- function generator
 This controls the amount of DC applied to the
output signal.
~oscilloscope||
 Oscilloscope
 The oscilloscope displays the amplitude and
frequency variations of electronic signals.

{general info:inst}     {adjusting the controls:ajo}
~ajo||
 Oscilloscope controls
   {spin selectors:sps}   {text fields:keys}

 {TIME BASE:os1}              {GROUND:os3}
 {X POS:os2}                  {TRIGGER:os4}

       {Y SCALE  [ /DIV ]:os5}
       {Y POS:os6}
       {AC | 0 | DC:os7}

 The oscilloscope has two input channels,
A and B, allowing two different signals to be
displayed simultaneously. These controls are on
the lower right of the scope face.

 If the {simulation:sim} is still valid, you can
move the probes from the oscilloscope to another
node. -- just click on AC or DC to redraw the
scope face with the new signal.
~os1||
 TIME BASE -- oscilloscope
 The TIME BASE (x-axis on the display) must be
adjusted relative to the signal frequency to get
a readable display. The TIME BASE box is a
{spin selector:sps} with values ranging from 0.1
nanoseconds to 0.5 seconds per horizontal
division. Thus if you want to see one cycle of a
1000 Hertz signal, the TIME BASE should be 0.1
milliseconds. One cycle at 10 KHz requires a TIME
BASE of 0.01 milliseconds.
~os2||
 X POS -- oscilloscope
 The value at X POS may be used to move the
trigger point along the x-axis. Note that the
vertical scale on the reticle of the scope does
not cross at zero on the x-axis. The trigger
point is at the left edge of the display when the
X POS is zero.
~os3||
 GROUND -- oscilloscope
 The ground symbol indicates where {ground} should
be connected on the scope icon. The oscilloscope
must be attached to a ground reference point in
the circuit for accurate displays.
~os4||
 TRIGGER -- oscilloscope
 Triggering controls when the waveform begins to
display. You can set this to start the trace
on the positive or negative slope of the input
signal on channel A, channel B, or an external
signal. The external trigger signal must be
attached to the terminal on the scope icon. The
level of the signal at which the display triggers
can be set with the spin selector.

Tip: If you don't get a trace when you think you
should, check the triggering. You can always
attach the trigger to ground to effectively keep
it on.
~os5||
 Y SCALE  [/DIV] -- oscilloscope
 You can adjust the value of the vertical divisions
and the origin on the y-axis independently for
each channel with their spin selectors. To get a
readable display you must adjust the y-scale
appropriately. An input signal of 1 volt will fill
the screen of the oscilloscope vertically if the
y-axis is set to 0.1 volts/division.
~os6||
 Y POS -- oscilloscope
 If you want to separate channels A and B by some
vertical distance to compare their waveforms, spin
select the y-position for each channel to move its
display up or down the screen.
~os7||
 AC | 0 | DC -- oscilloscope
 Each channel may be switched to show the AC
component of the signal or the sum of DC and the
AC components. Selecting 0 shows a flat line at
the origin set by Y POS.
~bode plotter||
 Bode plotter
 The Bode plotter will plot the frequency
response of circuits as amplitude against
frequency.

 Attach VI to the input and VO to the output of
the circuit. There must be a power source in
the circuit in addition to the plotter.

{general info:inst}     {adjusting the controls:ajb}
~ajb||
 Bode plotter controls
 After zooming the face of the instrument open,
set the initial and final frequency and amplitude
by using the respective {spin selectors:sps}. The
mode of plotting can be switched from logarithmic
to linear on each scale by clicking on the correct
buttons.

 You can read the frequency and amplitude of any
point on the waveform by moving the crosshairs to
it. Move the crosshairs by clicking on the arrow
buttons on the instrument face. You can also pick
the crosshairs up with the mouse and move them on
the plotter screen.
~crib||
 Useful formulas
  Ohm's Law:
             I = E/R   E = IR       R = E/I
  ______________________________________________

  Power:                   Û
             P = I◊R   I = √(P/R)   R = P / I◊
   _____________________________________________

  Resistance:

     Series           R = R– + R— + R“ + ...

                                  1
     Parallel         R = 
                            1    1    1
                             +  +  + ...
                            R–   R—   R“

                              V›‡ R–
  Attenuation:         V·„‚ = 
                              R– + R—
  ______________________________________________

  Capacitance:

      Parallel         C = C– + C— + C“ + ...

                                   1
      Series           C = 
                            1    1    1
                             +  +  + ...
                            C–   C—   C“
  ______________________________________________

  Capacitive Reactance:     X⁄ ˝ 1/(2πfC)

  Inductance:

      Serial                L = L– + L— + L“ + ...

      Parallel              L = 
                                 1    1    1
                                  +  +  + ...
                                 L–   L—   L“

  Inductive Reactance:      X› = 2πfL
  ______________________________________________

  Resonance:

          1                 1                 1
  f =      L =      C = 
           Û
        2π √LC            2π◊f◊C            2π◊f◊L

  Circuit Quality:

  Q = X/R = f/bandwidth

   

  Transformer Turns Ratio:

           a ˝ primary turns/secondary turns

           a ˝ primary Volts/secondary Volts

           a ˝ secondary Amps/primary Amps

               Û
           a ˝ √(Zprimary/Zsecondary)