Trim Pot symbol for express PCB layout

[Skywalker83]

What would a symbol for a trim pot look like for a PCB schematic? I'm doing my layout in Express PCB , and the only pots they have are Bourns series pots.

 

[crutschow]

A trimpot symbol looks like a standard potentiometer symbol.

What is a "series" pot?

 

[Skywalker83]

Ok.

Sorry, i dint mean "series" as in series or parrallel, i just meant they have Bourn potentiometers.


Also . Im using Express PCB, is there any PCB design software that is still free or really cheap, that is better than Express PCB?

Also.

Are there any places online where there are libraries of custom symbols for ExpressPCB. (ones that people have made).

 

[ericgibbs]

What would a symbol for a trim pot look like for a PCB schematic? I'm doing my layout in Express PCB , and the only pots they have are Bourns series pots.

hi,
The different symbol I use is a 'flat bar' for the wiper for a trimming pot
[usually set by using a trimming tool or screwdriver]

In my thinking the flat bar represents the 'slot' in the trimmer.

and and an 'arrow pointer' for the wiper on a variable resistor
[thats adjusted often by the user using a knob with a scaled indicator]

 

[KMoffett]

Create you own. One of the things I like about ExpressPCB. Take the standard potentiometer schematic symbol and "Ungroup" it. Make a 0.05"circle with the circle tool. Draw a diagonal line through the circle with the line tool. Place the circle/slash object near the potentiometer object, and Group the parts as a new component, Save the new schematic symbol in the Custom Components library for future use.

Ken

 

[KMoffett]

.....the only pots they have are Bourns series pots.

Are you talking about the schematic program, or the PCB program in ExpressPCB? In the schematic program, there is no definition of manufacturer or package. I think Eagle does that, because their PCB program automatically adds the correct component package from the schematic file when you open and link the PCB file. In ExpressPCB, you pick the correct package in the PCB program and then link it to the component in the schematic file through the "Part ID". So "R2" in the PCB file links to "R2" in the schematic file. You can create new component packages in the PCB program to fit the package you are going to use.

I recently needed two trim pot packages that weren't in the library, so created them. One of the Bourn's packages is on the right. Very easy!

Ken

 

[saturn1bguy]

If you're speaking of schematic capture, here's what I use (I haven't used their PCB layout):

 

[KMoffett]

If you're speaking of schematic capture, here's what I use (I haven't used their PCB layout):

If you do decide to use the PCB layout, and you are the type that ties the wiper of the trimmer to one of the ends (good practice) for a variable resistor, you will need to define three terminals in the schematic so you can match all three net list terminals on the PCB.

Otherwise, it works.

Ken