Category Archives: Hints & Tips

Component name abbreviations

Have you ever wondered which abbreviations to use when labeling components? Even when using just one design software, there might be different abbreviations in different libraries. For example, a crystal from one library can be labeled as Q1, then you add a transistor from another library and it will be labeled as Q2. Nothing sense. Sometimes when adding IC’s from different libraries, one is labeled as IC and another one as U. They should be both labeled as IC or U. I have seen crystals labeled as Q, X, XTAL, Y, etc. Which one is right? Or with transistors in different schematics it can be Q, T, TR, etc. Connectors might be X, J, P, CON or almost anything. There are some standards, but different kind of abbreviations are still widely used.

To clarify my own designs, I have decided to use following abbreviations. Earlier designs might use different abbreviations, but for every new design I will try use these as much as possible. This list will be a note to myself, but feel free to use it also if you want. They are not all standard, so you might want to check some abbreviations which one to use.

AE – Antenna
AT – Attenuator
BR – Diode bridge
BT – Battery
C – Capacitor
D – Diode (also Zener diodes)
DS – Display
F – Fuse
FB – Ferrite bead
FL – Filter
J – Connector (jack)
JP – Jumper
K – Relay
L – Inductor
LCD – Liquid crystal display
LDR – Light denendent resistor
LED – Light emmitting diode
LS – Loudspeaker
M – Motor
MIC – Microphone
(P – Plug connector)
PS – Power Supply
Q – Transistors, FET’s
R – Resistor
RN – Resistor network
RT – Thermistor
RV – Varistor
SW – Switch
SCR – Silicon controlled rectifier
T – Transformer
TC – Thermocouple
TP – Test point
TUN – Tuner
TVS – Transient voltage supressor, ESD-guard
U – Integrated circuits, operational amplifiers, optocouplers
V – Valve tube
VC – Variable capacitor
VR – Variable resistor
Y – Crystal / Oscillator

If you disagree with some abbreviations, feel free to comment.

Eagle: Text tool and Gerber files

I had a problem with text tool in Eagle. Text was normal in Eagle, but when exported it was bigger than it should. That’s not good when you are sending Gerber files for manufacturing.

Here is an example:

Text seems to be normal in Eagle.

This happens when exported. Text is overlapping with another.

 

 

 

 

 

 

 

 

 

Problem was that I was using proportional font-setting instead of vector. When exporting Gerber files, there is no support for proportional font and that’s why it happens. So, always use vector setting when you are going to export your design.

To solve problem, select “info” tool and click your text.

There is “Font” selection. Change “proportional” to “vector”.

Now, text should be seen as it will be exported.

To avoid this in future, you can change your user interface settings. On Eagle’s main display, select Options -> User interface.

This kind of window should open:

Check option “Always vector font”.

That’s it.