User Tools

Site Tools


glossary:glossary_g

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
glossary:glossary_g [2017/02/16 10:18]
WortingUK [GPIO]
glossary:glossary_g [2018/12/16 11:29] (current)
Mike Forrest
Line 2: Line 2:
 ~~NOTOC~~ ~~NOTOC~~
 [[start|Return to main Glossary index]] [[start|Return to main Glossary index]]
 +
 +===== Gerber =====
 +
 +A Gerber is a 2D binary vector image that describes every single layer of the PCB design. For instance, one Gerber describes the silk screen while the other describes the top, copper layer.
  
 ===== GIT repository ===== ===== GIT repository =====
Line 21: Line 25:
 ===== GPIO ===== ===== GPIO =====
  
-General-purpose input/​output is a generic pin on an integrated circuit or computer board whose behavior ​— including whether it is an input or output pin — is controllable by the user at run time. GPIO pins (generally) have no predefined purpose, and go unused by default.+General-purpose input/​output is a generic pin on an integrated circuit or computer board whose behaviorincluding whether it is an input or output pinis controllable by a program or script being run.  
 + 
 +GPIO pins (generally) have no predefined purpose, and go unused by default. Normally these are Tri-State pins.
  
 ===== GPP software ===== ===== GPP software =====
Line 32: Line 38:
  
  
-Is a common point in circuits ​normally 0 volts, but can be higher than 0 volt.+Electrical circuits (normally) have a common point from which voltages are measured.  
 + 
 +Historically this was the Ground (aka Earth), and could also have been the return path for electric current. 
 + 
 +In modern '​mains'​ AC power supplies, the '​Earth'​ line has a safety purpose and the '​Neutral'​ line is the '​Live'​ current return. NB: The Neutral is connected to Earth, somewhere further back in the supply system. 
 + 
 +Most modern low voltage and low power electronic ​circuits ​are NOT referenced to the Earth, but that name or Ground (aka GND) persists as the reference point, but more correctly its name is '​0V'​. The power supply modules for these circuits are said to be '​floating'​. Floating power supply modules ​can sometimes ​be identified by the use of a 2 wire connection to the mains. No harm will happen if the 0V line is connected to Ground. 
 + 
 +However, above a certain threshold of Voltage or Power or where a metal case/​chassis is used, modern regulations mean that an Earth connection is required and those power supply modules will use a 3 wire connection to the mains. An example of this is the MERG DCC power block
  
glossary/glossary_g.1487240302.txt.gz · Last modified: 2017/02/16 10:18 by WortingUK