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--- glossary:glossary_b [2018/11/21 10:45] – Bob Vetterlein
+++ glossary:glossary_b [2019/10/20 12:35] – [Back EMF] tom_shenton
@@ Line 6: / Line 6: @@
-Back EMF generally refers to the voltage that will appear across an inductor if the current is stopped suddenly and in particular to the voltage generated by the rotation of a motor.\\
+Back EMF generally refers to the voltage generated by the rotation of a motor but also to the voltage that will appear across an inductor if the current is stopped suddenly.\\
 [[:glossary:back_emf|Main article]]
 ===== Baud =====
-Most people use baud to describe modem speeds in bits per second–but they are wrong. They may say a 9,600-bps modem transmits at 9,600 baud, but really baud is a measure of how frequently sound changes on a phone line. Modern modems transmit more bits with fewer changes in sound, so baud and bps numbers are not equal. However, only editors, pedants, and communications engineers now care about the distinction. But if you run into members of these groups, use bps instead of baud.\\
+Baud in communications refers to changes per second. In the very early days of MODEMs, for example, each bit sent equaled a single change, so baud equaled bits per second (BPS). The terms were initially interchangable. As newer modulation methods (the way the signal is sent or encoded) came along a baud represented more than one bit per second. For example a single baud may have represented two, three or four bits for each change. From that point forward, baud and BPS were no longer the same, though many people still use the terms interchangably. For the sake of clarity, use BPS to represent the number of bits sent per second.\\
-[[http://www.cnet.com/Resources/Info/Glossary/Terms/baud.html|http://www.cnet.com/Resources/Info/Glossary/Terms/baud.html]]
+[[wp>Baud|Baud]]
 ===== BC3 =====
@@ Line 28: / Line 26: @@
-Bell Signals were used to convey information from between signal boxes.\\
+Bell Signals are used as part of a block signaling protocol.
-[[http://www.signalbox.org/block/bells.shtml|http://www.signalbox.org/block/bells.shtml]]
+The cadence of the Bell Signals were used to convey information. An example would be two bell rings would mean a train is entering a section and two rings followed by one ring may mean the train is clearing a section.
+Though there are some universal bell signals, different railroads at different times have had their own signaling schemes.
+\\
+[[https://signalbox.org/block.shtml|THE SIGNAL BOX website - Block System]]
 ===== BGA =====
@@ Line 96: / Line 99: @@
-Byte per second. In telecommunications and computing, bit rate (sometimes written bitrate or Rbit) is the number of bits that are conveyed or processed per unit of time. In digital multimedia, bit rate is the number of bits used per unit of time to represent a continuous medium such as audio or video. It is quantified using the bit per second (bit/s) unit or some derivative such as Mbit/s.\\
+Bits per second. In telecommunications and computing, bit rate (sometimes written bitrate or Rbit) is the number of bits that are conveyed or processed per unit of time. In digital multimedia, bit rate is the number of bits used per unit of time to represent a continuous medium such as audio or video. It is quantified using the bit per second (bit/s) unit or some derivative such as Mbit/s.\\
 While often referred to as "speed", bit rate does not measure distance/time but quantity/time, and thus should be distinguished from the "propagation speed" (which depends on the transmission medium and has the usual physical meaning).