glossary:glossary_a
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glossary:glossary_a [2015/01/09 01:38] – external edit 127.0.0.1 | glossary:glossary_a [2021/09/22 09:51] – used the correct syntax for linking to Wikipedia (so the icon is correct) Wayne | ||
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- | Alternating Current | + | Alternating Current. Refers to a situation where current flows back and forth through a conductor (wire) in alternating directions. |
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+ | The opposite of AC is DC where the current only flows in one direction. DC will have a voltage level in only one direction, either positive or negative, referenced to a common, ground or zero volts reference point. | ||
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+ | Mains power in many countries such as Britain, Australia | ||
+ | \\ | ||
[[http:// | [[http:// | ||
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- | [[:glossary#dcc_digital_command_control|DCC]] decoders are used to control trackside accessories such as turnouts and signals using the NMRA standard pulsed signal. The signal can be carried by the track and track feeders or can be a separate circuit, which avoids the risk of a derailment or short preventing the control of the turnouts. All DCC manufacturers make accessory decoders and MERG provide kits.\\ | + | **[[glossary:glossary_d#dcc|DCC]]** decoders are used to control trackside accessories such as turnouts and signals using the NMRA standard pulsed signal. The accessory decoder is controlled similar to a train decoder using a unique decoder address and a series of function variables. The signal can be carried by the track and track feeders or can be a separate circuit, which avoids the risk of a derailment or short preventing the control of the turnouts. |
- | http:// | + | https:// |
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- | The MERG DCC accessory encoder is designed to operate as a DCC command station independently from the track DCC although it uses the NMRA Standard for its information encoding and can operate most other accessory decoders as well as the MERG kits.\\ | + | The MERG DCC accessory encoder is designed to operate as a DCC command station independently from the track DCC. It uses the NMRA Standard for its information encoding and can operate most other accessory decoders as well as the MERG kits.\\ |
- | http:// | + | https:// |
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- | Address is the unique identification of anything. In the context of DCC it means the coding of each loco or other decoder, which ensures that it identifies the signals intended for it. | + | Address is the unique identification of anything. In the context of DCC it means the coding of each loco or other decoder, which ensures that it identifies the signals intended for it. |
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+ | You will encounter two address ranges in the NMRI DCC standard, two-digit addressing (called short addressing) and four-digit addressing (called long or extended addressing). The number of digits refers to how many hexadecimal digits are transmitted/ | ||
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+ | DCC decoders store the addresses in Configuration Variables (CVs). Each decoder vendor may have different set of CVs to store the digits. Refer to the docs that came with your decoder. | ||
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+ | ===== Agile ===== | ||
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+ | Agile is a Manifesto for Software Development. It aims to deliver working software quickly. See | ||
+ | [[http:// | ||
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- | An Amplifier is a device | + | An Amplifier is a device |
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+ | You will generally run into three amplifier types on the MERG forum or with MERG kits; a transistor as an amplifier, an Operational Amplifier (op amp) such as an LM324 or an audio amplifier such as an LM386. | ||
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- | ===== Amps ===== | + | ===== Amps or Ampere |
- | The unit of current. It is defined as the constant | + | An ampere is a measure |
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+ | In the model railroad context, you would expect to see a DC supply or a DCC booster providing several amps of current to a track, and most other circuits | ||
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+ | In a home environment, | ||
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American Standard Code for Information Interchange | American Standard Code for Information Interchange | ||
[[glossary: | [[glossary: | ||
- | [[http:// | + | [[wp>ASCII|ASCII]] |
===== Aspect ===== | ===== Aspect ===== | ||
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- | ===== Auto reverse | + | ===== AT-Bus |
+ | An alternative CAN Bus protocol devised by MERG member Roger Edwards which overcomes what he sees as deficiencies in the [[glossary: | ||
- | An auto reverse module is used in DCC to prevent shorts in reversing loops and other situations where the polarity of two lines must be reversed for a train to run through. It works by reversing the polarity if a short is detected. If the short is eliminated then the new polarity is accepted and is kept. One auto reverse module can protect several track sections provided that only section break is being bridged by a loco at any one time. | + | ===== Auto Reverse Module ===== |
+ | An auto reverse module is used in DCC to prevent shorts in reversing loops and other situations where the polarity of two lines must be reversed for a train to run through. It works by reversing the polarity if a short is detected. If the short is eliminated then the new polarity is accepted and is kept. One auto reverse module can protect several track sections provided that only one section break is being bridged by a loco at any one time. | ||
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+ | ===== AVR ===== | ||
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+ | AVR is the name of a microcontroller family used in many [[: | ||
+ | See [[wp> | ||
===== AWG ===== | ===== AWG ===== | ||
+ | American Wire Gauge is a set of standard sizes for wire diameter. It covers both solid and stranded wire. | ||
- | American Wire Gauge- This is not the same as Standard Wire Gauge. There is no direct conversion in that the ratio of radii SWG/AWG varies from 0.8 at 6/0 to 1.64 at 43.\\ | + | As the gauge number gets larger the wire diameter gets smaller. Larger wire is generally used for carrying higher current levels since larger wire has less resistance and so for higher currents less voltage is dropped over a given distance. |
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+ | In North America, extension cords are generally wired with 16AWG or 14AWG. House outlet wiring would generally have 14AWG or 12AWG wiring. In the UK, Australia and many other countries 2.5mm or 4mm wiring would be used in a similar fashion. Bus wires for DC or DCC may use large gauges such as these to supply a fairly constant voltage level (provides a low voltage drop over distance) around a large layout. Feeders to a track would be much smaller wires as current demands would be smaller. Relay coils and small wattage transformers may have gauges from 18AWG down to 28AWG. Wirewrap wire is generally 26AWG. While this paragraph is fairly general, it will give you an idea what to expect for wire sizes on a layout or simple projects. Better detail and recommendations can be found elsewhere in the Forum for a specific task. | ||
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+ | AWG is not the same as Standard Wire Gauge. There is no direct conversion in the ratio of wire diameter between | ||
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+ | \\ | ||
[[http:// | [[http:// | ||
[[http:// | [[http:// | ||
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glossary/glossary_a.txt · Last modified: 2022/04/29 19:54 by sven-e