Spectrum Software
Industrial Strength Simulation




Spectrum Software has released Micro-Cap 11, the eleventh generation of our SPICE circuit simulator.

For users of previous Micro-Cap versions, check out the new features available in the latest version. For those of you who are new to Micro-Cap, take our features tour to see what Micro-Cap has to offer.




Easily Overlooked Features


This section is designed to highlight one or two features per issue that may be overlooked because they are not made visually obvious with a toolbar button.

Changing Multiple Component Values
Changing the values of multiple components at once has obvious benefits over clicking on and editing each of the components individually. There are two main methods for performing this operation.

.Define Statement
When placing a component in the schematic, you can define the appropriate attribute with a symbolic name and then use a .define statement to actually define the value. Multiple components would be defined with the same .define statement. For example, you may want to define the Model attribute of multiple resistors with the symbolic name TOLS. In the text area of the schematic, you would have statements such as:

.define TOLS Resmod5
.model Resmod5 Res (R=1 Lot=5%)
.model Resmod10 Res (R=1 Lot=10%)

To easily change the model of all of the resistors that use the define statement you would just need to change the .define statement so that TOLS references the Resmod10 model. The drawback of this is that if you change the .define statement you change the value of all components that reference it so you can't pick and choose which components to change.

Change button in the Attribute dialog box
To pick and choose the components you want to edit, use the Change button that is in the upper right hand corner of the Attribute dialog box. The Change button invokes the Change Attribute To dialog box which provides a list of all of the components that are of the same type that reside in the schematic. Select the components from this list, and the edit for that specific attribute will be applied to all of them. For example, if you want to change the model of multiple resistors, you would double click on one of the resistors to be changed. Edit the model attribute for that resistor and then hit the Change button. A list of all of the resistors in the schematic will appear. Choose the other resistors that you want the new model to be applied to and hit OK. The model for all of the selected resistors will be set to the new value.
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