Knowledgebase glossary

glossary:asciicode

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:44+00:00

ASCII American Standard Code for Information Interchange Control Codes These are non printable characters that control the operation of the communication equipment: Hex Dec Code Description Hex Dec Code Description 00 0 NUL Null 10

glossary:atcdemo2

Anonymous (anonymous@undisclosed.example.com) — 2024-10-02T10:46:01+00:00

Shuttle Demo - ATC & CSR4 The ATC & CSR4 kits shown here have been discontinued and replaced by ATC2 & ENDS, functionality remains the same, the PCBs have been redesigned to provide greater flexibility in implementing more complex setups. The shuttle module or ATC (Automatic Train Controller)

glossary:back_emf

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:44+00:00

Back EMF 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. In the latter case the voltage acts to reduce the current driving the motor so that the power consumed gets less as the speed rises to that speed at which the BEMF is equal to the applied voltage. If the BEMF exceeds the applied voltage the current will be reversed and the motor will be acting as a generat…

glossary:bridge_rectifier

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:44+00:00

Bridge rectifier A diode bridge (occasionall called a Graetz bridge)is an arrangement of four diodes connected in a bridge circuit as shown below, that provides the same polarity of output voltage for any polarity of the input voltage. When used in its most common application, for conversion of alternating current (

glossary:capacitor

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:44+00:00

Capacitor A capacitor can store electric energy when disconnected from its charging circuit, so it can be used like a temporary battery. Capacitors are commonly used to supply energy to electronic devices without the memory being lost when changing their batteries.

glossary:diode

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:44+00:00

Diode The DIODE is an electronic component that allows the passage of current in only one direction. They are solid state semiconductor devices and typically need more than 0.6 volts to operate. In a normal diode, current flows from the positive anode to the negative cathode. Early diodes were in reality, vacuum-tube rectifiers, consisting of an evacuated glass or steel envelope containing two electrodes—a cathode and an anode. Because electrons can flow in only one direction, from cathode to a…

glossary:exhibition_stand

Anonymous (anonymous@undisclosed.example.com) — 2025-10-21T14:24:02+00:00

The MERG Exhibition Stand Here is a photo of part of MERG's Exhibition stand taken at the 2011 Ally Pally Exhibition. Click on the image to see a larger version. At the top of the display in the foreground is the Hysteresis Loop so called for its resemblance to a hysteresis graph. Below this is the

glossary:glossary_a

Anonymous (anonymous@undisclosed.example.com) — 2025-12-05T12:16:44+00:00

Glossary A Return to main Glossary index AC Alternating Current. Refers to a situation where current flows back and forth through a conductor (wire) in alternating directions. Generally, the voltage being applied to the conductor has a changing (alternating) polarity so the current has to change direction related to which end of the wire is positive or negative at a given point of time. In most cases we encounter, the voltage moves in a sinusoidal wave shape centered at zero volts, though it…

glossary:glossary_b

Anonymous (anonymous@undisclosed.example.com) — 2025-02-22T13:59:23+00:00

Glossary B Return to main Glossary index Back EMF Back Electromotive Force (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 changed or stopped suddenly. Main article 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 (

glossary:glossary_c

Anonymous (anonymous@undisclosed.example.com) — 2026-01-21T12:14:59+00:00

Glossary C Return to main Glossary index C/MRI Bruce Chubb's Computer/Model Railroad Interface system C/MRI. A series of modules and support available for the system obtained from JLC Enterprises Inc. For website see links page Cab Control A system of control using DC power where more than one controller or cab is used to drive trains across the tracks controlled by another controller. This requires switches to transfer the supply from the cabs to the parts of the layout they will control,…

glossary:glossary_d

Anonymous (anonymous@undisclosed.example.com) — 2025-10-31T12:38:15+00:00

Glossary D Return to main Glossary index D Type Connector A D type connector gets its name from the D shape of the surround to the pins and socket. The most common types contain either 9 or 25 pins. It is common for some of the pins to be missing from the connector or to have pins that are not connected to the attached cable. These connectors are said to have genders which relates to a pin being a male connection and a socket being the female connection. To be clear, the male connector has …

glossary:glossary_e

Anonymous (anonymous@undisclosed.example.com) — 2021-08-08T05:32:13+00:00

Glossary E Return to main Glossary index EDG Event Data Grid in the FCU (FLiM Configuration Utility) used to configure CBUS systems. The grid allows you to collect a matrix of events(actions), which nodes they are associated with and what they triggered to happen as a result of the event occurring. The entries can be viewed or subsequently used to train (program) a Consumer (node that acts on events) to perform the action each time the event occurs. See the

glossary:glossary_f

Anonymous (anonymous@undisclosed.example.com) — 2025-07-22T05:35:37+00:00

Glossary F Return to main Glossary index Faller Manufacture Model Railway accessories and buildings. Faller road system MERG TBA36/1&/2 - merg members only FallerCarSystem Batter powered H0 vehicles with a steering rack fitted with a small magnet. The vehicle follows an iron wire hidden in the roadway.

glossary:glossary_g

Anonymous (anonymous@undisclosed.example.com) — 2022-03-24T20:13:39+00:00

Glossary G 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 is a popular version control system primarily used for managing software source code, but is also used for managing firmware, documentation

glossary:glossary_h

Anonymous (anonymous@undisclosed.example.com) — 2021-08-08T05:50:14+00:00

Glossary H Return to main Glossary index Hall effect sensor A Hall effect sensor is a semiconductor device often looking like a small transistor. When the device encounters a magnetic field it generates a voltage. There are many uses for a Hall sensor such as measuring the speed of a fan or replacing the points in a automobile distributor (detects speed and position to fire the ignition). In the context of the

glossary:glossary_i

Anonymous (anonymous@undisclosed.example.com) — 2023-07-25T16:55:12+00:00

Glossary I Return to main Glossary index ICs An integrated circuit (IC) is an electronic component which typically packages a collection of transistors, diodes and resistors to perform some useful function. There are numerous types with many package configurations. You may be familiar with fairly simple ones like Operation Amplifiers (Op Amps) or

glossary:glossary_j

Anonymous (anonymous@undisclosed.example.com) — 2024-09-21T18:08:53+00:00

Glossary J Return to main Glossary index JAL Just Another Language This is a language for programming PIC chips. All the PMP kits that use PIC chips are programmed using this language. It is an excellent way of getting into programming these devices to assist conltrol of items on your layout.

glossary:glossary_k

Anonymous (anonymous@undisclosed.example.com) — 2021-07-24T16:24:09+00:00

Glossary K Return to main Glossary index Kits Sets of parts and instructions to build things. MERG provides many projects as kits for members, available in Kitlocker. Kitlocker, Members Only. KnowledgeBase A KnowledgeBase is a means of storing information which can be structured or unstructured, so that particular information can be searched and recovered. In

glossary:glossary_l

Anonymous (anonymous@undisclosed.example.com) — 2025-07-21T08:09:01+00:00

Glossary L Return to main Glossary index Latching Latching can apply to both mechanical devices and electronic circuits. An example of mechanical latching would be a push on / push off switch, see here. See also description of a latching relay. (e.g. relay) An example of an electronic latch would be a flip-flop or bistable circuit.

glossary:glossary_m

Anonymous (anonymous@undisclosed.example.com) — 2021-08-11T12:57:45+00:00

Glossary M Return to main Glossary index Magnet A magnet is an object that has a magnetic field. It can be in the form of a permanent magnet or an electromagnet. Magnet Matrix Wikipedea's Matrix entry Main article available to MERG Members only. Memory Wire Wire made from a special alloy which changes its molecular structure at a certain temperature causing it to shrink. This effect can usefully be applied to point and signal actuation. Some types require a tension spring to pull it bac…

glossary:glossary_n

Anonymous (anonymous@undisclosed.example.com) — 2024-03-04T17:15:09+00:00

Glossary N Return to main Glossary index NAND NAND Logic Gate Negative A DC term that means the voltage is lower than 0. You can have it plus or minus the zero point NMRA The National Model Railroad Association in the USA is the largest organization devoted to the development, promotion, and enjoyment of the hobby of model railroading. The

glossary:glossary_o

Anonymous (anonymous@undisclosed.example.com) — 2021-08-08T06:20:09+00:00

Glossary O Return to main Glossary index Octal Darlington Arrays Circuit diagram of Darlington configuration In electronics, the Darlington transistor is a semiconductor device which combines two bipolar transistors in tandem (often called a “Darlington pair”) in a single device so that the current amplified by the first is amplified further by the second transistor. This gives it high current gain (written β or hFE), and takes up less space than using two discrete transistors in the same…

glossary:glossary_p

Anonymous (anonymous@undisclosed.example.com) — 2025-07-07T12:23:15+00:00

Glossary P Return to main Glossary index Parallel * Pertaining to the shunt connection of components or circuits. * Pertaining to the type of operation in a computer when all elements in an information item (e.g., bits in a word) are acted upon simultaneously, rather than serially (one at a time)

glossary:glossary_q

Anonymous (anonymous@undisclosed.example.com) — 2018-10-13T09:26:20+00:00

Glossary Q Return to main Glossary index QFN Quad Flat No-leads package QFP Quad Flat Package QTU The QTU (Quad Throttle Unit) by Howard Amos is intended to be a throttle (controller) unit for use on a model railway. In fact four throttles are built into a single card. These four throttles can be used as conventional manual throttles by connecting potentiometers for speed and switches for brake and reverse. Inertia potentiometers can also be added so that speed changes are gradual. Track…

glossary:glossary_r

Anonymous (anonymous@undisclosed.example.com) — 2025-09-19T08:47:50+00:00

Glossary R Return to main Glossary index RailCom RailCom is the bidrectional (return) element of DCC, although not released at the same time as the main elements of DCC the bidirectional side was introduced in 2011. The susbsystem enables selected CV data held within the loco or accessory decoder to be transmitted back the the command station or in the case of loco

glossary:glossary_s

Anonymous (anonymous@undisclosed.example.com) — 2025-02-22T13:57:46+00:00

Glossary S Return to main Glossary index SABLE Stash Acquired Beyond Life Expectancy. A stash of “useful things” a hobbyist has acquired and cannot bring themself to throw out in case they might be needed. Schottky Diode Named after the German physicist Walter H. Schottky, a Schottky diode is a solid state diode formed by the junction of a semiconductor with a metal. It is used when a low forward voltage drop or high switching speed is required. A conventional solid state silicon diode has…

glossary:glossary_t

Anonymous (anonymous@undisclosed.example.com) — 2026-01-21T19:04:03+00:00

Glossary T Return to main Glossary index Tag strip Point-to-point construction uses terminal strips (also called 'tag boards' of 'tag strips'). A terminal strip is a stamped strip of tin-plated loops of copper. It is mounted in a way that electrically insulates it. The metal loops are mounted on a cheap, heat-resistant material, usually synthetic-resin bonded paper (FR-2), or bakelite reinforced with cotton, or sometimes paxolin. The insulator has an integral mounting bracket, sometimes shor…

glossary:glossary_u

Anonymous (anonymous@undisclosed.example.com) — 2021-09-24T03:59:09+00:00

Glossary U Return to main Glossary index UART or USART Universal Asynchronous Receiver / Transmitter Universal Asynchronous / Synchronous Receiver / Transmitter A UART is a logic IC that typically converts parallel data to an asynchronous (async) serial stream or its reverse. Some UARTs also incorporate data buffers, serial clock circuits and control line logic/signals. The most common type of UARTs people are familiar with have been used in personal computers as asynchronous serial ports…

glossary:glossary_v

Anonymous (anonymous@undisclosed.example.com) — 2025-07-22T05:41:11+00:00

Glossary V Return to main Glossary index Via On a printed circuit board, a Via is a through hole connection between the top and bottom conductor layers. It is usually a smaller hole than those provided to fit components and does not require any attention when building the board

glossary:glossary_w

Anonymous (anonymous@undisclosed.example.com) — 2021-07-24T16:25:53+00:00

Glossary W Return to main Glossary index Watt A unit of power most often used in the electrical and electronic industries and is defined as one joule of energy per second. Named after the British Engineer James Watt, it was adopted by the Second Congress of the British Association for the Advancement of Science in 1889. All household appliances have the amount of power in watts that they consume imprinted somewhere on the casing. Watts in the electronic arena are calculated as volts x ampere…

glossary:glossary_x

Anonymous (anonymous@undisclosed.example.com) — 2021-08-08T07:46:09+00:00

Glossary X Return to main Glossary index XLR The XLR connector is a style of electrical connector, primarily found on professional audio, video, and stage lighting equipment. XLR Connector XOR Exclusive OR Logic Gate An XOR (exclusive OR) gate is a logic gate which produces a high state only if there is an odd number of high inputs. It is similar to an OR gate except an OR gate will additionally give a high output if the inputs are all high.

glossary:glossary_z

Anonymous (anonymous@undisclosed.example.com) — 2021-08-08T07:49:50+00:00

Glossary Z Return to main Glossary index Zener diode A type of diode named after the American physicist Clarence Melvin Zener who discovered a method of creating controlled breakdown at a specific voltage in a specially doped P-N semiconductor junction. When reversed biased, the zener diode behaves like a conventional diode and passes little or no current until the reverse voltage reaches the breakdown voltage when current will begin to flow. At this point the reverse voltage is maintained m…

glossary:hysteresisloop

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:46+00:00

Hysteresis Loop - RPC Demonstration The track on this demo is divided into 8 sections, these are monitored for occupation using a DTC, MERG Kit 56. The two points are driven using PMR1 kits, one is clearly visible in the foreground of the photo, mounted on the point motors are switches which are used to feed back the actual point position via a SRI4 kit. The signals, which are for demonstration only and are not intended to be scale models, consist for the most part of 4 LEDs which are individua…

glossary:hystloopbox

Anonymous (anonymous@undisclosed.example.com) — 2025-09-13T11:16:23+00:00

Hysteresis Loop - The RPC Control Box Overview Here we have the box containing the RPC modules that control the hysteresis loop demonstration. At the top, connected to a grey Cat5 cable coming in from the right is a RSS (Remote Stack Slave), moving down the 'Stack' we have next a

glossary:logicgates

Anonymous (anonymous@undisclosed.example.com) — 2019-04-03T12:46:41+00:00

Logic Gates Overview This page gives a brief description of the principal logic gates, a detailed description will be found in Wikipedia by clicking on each of the images. A more detailed overview is in Wikipedia here. Return to main Glossary index AND Boolean operator which is used to join two or more statements so that the final statement is true only if the individual statements are all true. Thus (X>1)AND(X<2) is true if X is between 1 and 2.

glossary:mergcbus

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:48+00:00

MERG CBUS Demonstration As explained on the New DCC System page, DTC-8 boards show track occupancy. These feed into a CANACE8C (kit 89) which acts as a “producer” to send messages via CBUS to a CANLED (kit 82). Attached to the CANLED is a TM4 test board (kit 901) populated with LEDs to show an approximation of the track diagram. As a locomotive moves around the layout, its position can be seen on the TM4.

glossary:mergdcc

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:48+00:00

MERG DCC System Demonstration This uses MERG's DCC Command Station (kit 91) connected to MERG's DCC Handset (kit 92) via the CANRJ22 connector (kit 92V). A CAB Holder (kit 673) is used to hold the Handset. The track is divided into 7 sections and the DTC8

glossary:rpcsystem

Anonymous (anonymous@undisclosed.example.com) — 2023-10-24T17:53:49+00:00

RPC Remote Panel Control Return to main Glossary index Overview A system for the remote control of model railway layouts, devised by long term MERG member Gordon Hopkins. The system consists of a PC interface module known as the RPIC (or RPI, see below) and a number of general purpose or special purpose Input/Output modules designed to plug directly to the interface, or one another, forming what is refered to as a module 'Stack'. Options also exist to use the Input/Output modules without a…

glossary:shiftinout

Anonymous (anonymous@undisclosed.example.com) — 2014-11-11T13:29:48+00:00

Shift registers as used in RPC Modules Extensive use is made of shift registers in the RPC system. Serial in Parallel out (SiPo) registers are used to receive data from the PC and deliver it as discrete output to the layout. While Parallel in Serial out (PiSo) registers receive discrete inputs from sensors and the like and deliver them to the PC as a data stream. Below is Fig.7 extracted from

glossary:start

Anonymous (anonymous@undisclosed.example.com) — 2026-02-09T08:24:35+00:00

Jargon Buster This page is based on the original MERG glossary. Before adding entries, please read guide to adding entries a how to do it for MERG Members. A AC - Alternating Current Accessory decoders Accessory encoder Address AFAIK - As far as I know Agile Amplifier AM - Amplitude Modulation

glossary:thomasbc3

Anonymous (anonymous@undisclosed.example.com) — 2025-02-22T14:02:37+00:00

Superbloc BC3 Demonstration - now retired This demonstration cabinet contains an oval of track which is divided into 4 sections. Each of these was controlled by a BC3, MERG Kit 38. These were arranged for anticlockwise travel, if on entering a section the section in advance was occupied then the train would be brought to a halt. There are also 4 signals which reflect the status on the section in advance, these are driven by

glossary:thomasrfid

Anonymous (anonymous@undisclosed.example.com) — 2019-02-26T18:01:25+00:00

RFID Radio Frequency IDentification Demonstration Follow these two links for a description of the track and Control modules used in this cabinet. RFID uses small glass encapsulated 'tags', these contain a transmitter that when energised by a field generated by the 'reader' transmit a unique number which is received by the reader and passed as serial data to a PC. In this demonstration the tags are mounted on various items of stock, when they pass the reader a Powerpoint presentation is caused …