11.10. Power Symbols

11.10. Power Symbols

Power symbols are created the same way as normal components. It may be useful to place them in a dedicated library such as power.lib. Power symbols consist of a graphical symbol and a pin of the type “Power Invisible”. Power port symbols are handled like any other component by the schematic capture software. Some precautions are essential. Below is an example of a power +5V symbol.

To create a power symbol, use the following steps:

• Add a pin of type “Power input” named +5V (important because this name will establish connection to the net +5V), with a pin number of 1 (number of no importance), a length of 0, and a “Line” “Graphic Style”.
• Place a small circle and a segment from the pin to the circle as shown.
• The anchor of the symbol is on the pin.
• The component value is +5V.
• The component reference is \#+5V. The reference text is not important except the first character which must be # to indicate that the component is a power symbol. By convention, every component in which the reference field starts with a # will not appear in the component list or in the netlist and the reference is declared as invisible.

An easier method to create a new power port symbol is to use another symbol as a model:

• Load an existing power symbol.
• Edit the pin name with name of the new power symbol.
• Edit the value field to the same name as the pin, if you want to display the power port value.
• Save the new component.