mfx and mfx+
Compatible locomotives register automatically. Their names, functions and icons are transferred to a compatible controller.
Centre contact, pickup shoes and automatic locomotive registration
H0 AC Model Railway: Märklin, mfx & C Track
H0 AC describes the Märklin-compatible centre-contact system at a scale of 1:87. Stud contacts supply power to the pickup shoe beneath the locomotive, while both running rails form the common return conductor. Modern layouts primarily use mfx, mfx+, Motorola and, in some cases, DCC.
Scale 1:87
Track gauge 16.5 mm
More than 100 direct shop links
Stud contacts instead of separate rail poles
How does an H0 AC model railway work?
Small stud contacts are positioned between the running rails. A centre pickup shoe beneath the locomotive collects power from these contacts. The wheels return the current through both outer rails. This principle technically distinguishes H0 AC from the two-rail system.
The term AC originates from the era of analogue alternating-current operation. A modern digital layout carries an encoded digital signal in the track. The important terms today are therefore centre contact, pickup shoe and digital protocol.
Märklin forms the largest part of this system. PIKO, Roco, BRAWA, ESU and other manufacturers also offer selected locomotives in AC, three-rail or centre-contact versions.
Before purchasing any vehicle
Check for an AC, three-rail or centre-contact version
An H0 two-rail locomotive normally has no pickup shoe and cannot operate on centre-contact track without a technical conversion.
From the first C Track oval to a large layout
Which introduction suits an H0 AC layout?
A complete digital starter set contains a locomotive, rolling stock, C Track, a track box, power supply and usually a Mobile Station. Additional mfx locomotives can then register automatically, while further electromagnetic accessories can be controlled.
An existing C Track oval can be extended gradually with turnouts, parallel tracks, station tracks and a second electrical district. Märklin K Track is also suitable for a permanently ballasted layout.
Large layouts may add a Central Station, feedback modules, boosters, turnout decoders and separate power supplies for several layout districts.
H0 AC Getting-Started Finder
Digital H0 AC Starter Set
Starter sets combine C Track, digital control and suitable centre-contact vehicles.
Open Section
Roadbed track, flexible track and existing layouts
Compare Märklin C Track, K Track and M Track
| Track system | Construction | Strength | Particularly suitable for |
|---|---|---|---|
| Märklin C Track | Plastic roadbed with a clip connection | Quick assembly, concealed drives and robust contacts | Starter sets, floor layouts and permanent digital layouts |
| Märklin K Track | Track without fixed roadbed | Custom ballasting and flexible track | Permanent, prototype-oriented layouts |
| Märklin M Track | Historic metal-roadbed track | Large second-hand supply and nostalgic operation | Existing layouts and collector operation |
| Transition Track | Connects different Märklin track systems | Gradual conversion of an existing layout | C/K or C/M combinations |
Contact tracks
Feedback through an insulated outer running rail
Because both running rails normally form a common return conductor, one outer rail can be insulated in individual sections. A non-insulated AC wheelset reconnects it to the common return when the vehicle enters the section.
Automatic registration, feedback and power
Digital control for an H0 centre-contact layout
Motorola and DCC
Many command stations and multi-protocol decoders also support older Motorola vehicles and modern DCC locomotives.
Mobile Station
A compact handheld controller for locomotives and electromagnetic accessories. A suitable track box is required for a direct connection to the track.
Central Station 3
A large system controller for routes, feedback, track diagrams, automation, networking and extensive locomotive functions.
s88 Feedback
Contact tracks, push buttons and occupancy detectors provide information to the command station or control software.
Booster Districts
Larger layouts are divided into separate power and short-circuit districts.
From a track oval to an automated station
Build an H0 AC layout in four steps
Define the radius
360 mm is compact; long coaches benefit from wider radii.
Define the train length
Size platforms and storage sidings for the longest train.
Distribute the power
Provide several feeds and separate booster districts.
Plan the feedback
Electrically isolate contact tracks before adding ballast.
Electrical Safety
Booster districts must be separated completely and unambiguously
The centre conductor is separated at the district boundary. Common return connections, feedback and shared accessory supplies should be planned according to the instructions for the command station in use.
Combine locomotives, rolling stock and accessories correctly
What is compatible between H0 AC and H0 DC?
| Component | Directly usable? | Check or conversion |
|---|---|---|
| H0 DC Locomotive | Normally no | Adapt the pickup shoe, wiring, wheelsets and decoder. |
| Unlit Coach or Wagon | Often yes | Check the wheelset dimensions, turnout operation and coupling. |
| Illuminated Coach | Only with suitable current collection | Check the pickup shoe, return contact and decoder. |
| Buildings and Figures | Yes | The scale of 1:87 is identical for both systems. |
| Digital Command Station | Protocol-dependent | Compare support for mfx, Motorola and DCC. |
Vehicles, track, digital technology and scenery
Product categories for H0 AC and Märklin-compatible layouts
H0 AC Starter Sets
Locomotive, rolling stock, C Track and control
AC Steam Locomotives
mfx, sound and smoke-equipped models
AC Diesel Locomotives
Shunting, main-line and private-railway locomotives
AC Electric Locomotives
Taurus, Vectron, Traxx and classic locomotives
AC Multiple Units
ICE, Talent, RegioSwinger and regional services
H0 Passenger Coaches
Long-distance, regional and heritage services
H0 Freight Wagons
Tank, container and open wagons
H0 Track
C Track, K Track and transition sections
H0 Turnouts
Standard, curved and slim turnouts
Track Extension Sets
Stations, parallel circuits and storage sidings
Track Accessories
Drives, decoders and connection materials
Digital Command Stations
Mobile Station, CS3 and multi-protocol systems
Digital Modules
s88, boosters and accessory decoders
Multi-Protocol Decoders
mfx, Motorola and DCC
Sound Decoders
LokSound, SmartDecoder and mSD
Power Buffers
Bridge brief contact interruptions
H0 Signals
Semaphore, colour-light and shunting signals
H0 Overhead Line
Masts, contact wire and accessories
Layout Lights
Platform, street and building lighting
Residential Buildings
Towns, villages and housing estates
Railway Staff
Drivers, shunters and passengers
Deciduous Trees
Avenues, gardens and woodland
Coniferous Trees
Spruce, fir and pine trees
Vehicle Lighting
Interior lighting, LEDs and pickup shoes
Centre-contact vehicles and system components
Important manufacturers for H0 AC
BRAWA
Selected locomotives and rolling stock for centre-contact track.
Decoders and LocoNetUhlenbrock
Multi-protocol decoders, Intellibox and diagnostic equipment.
Modules and FeedbackTams Elektronik
s88, boosters and digital layout modules.
Signals and ControlViessmann
Signals, overhead line and digital switching technology.
Selected current centre-contact products
Starter sets, locomotives, track and digital technology
Start digitally
Starter set and modern vehicles
Starter Set
Märklin 29249 Local Freight Train
Class 24, freight wagons, C Track and a Mobile Station.
View product
Multiple Unit
PIKO 21826 Talent 2
Five-part regional multiple unit with AC sound.
View product
mfx Sound
Märklin 39111 Class 110.3
Striking TRI electric locomotive with extensive functions.
View product
Taurus
Roco 7520240 ÖBB 1116
Eurovision special-livery locomotive with AC sound.
View product
Diesel Locomotive
Roco 7320041 Class 218
Ocean blue and beige Deutsche Bundesbahn locomotive with sound.
View product
Bahnbau
PIKO 52157 Class 232
Heavy yellow engineering-train locomotive with AC sound.
View product
C Track
Märklin 24802 Digital Set
Track and two digitally equipped turnouts.
View product
More direct product links
More H0 AC products by vehicle and technology group
AC Steam Locomotives
- Märklin 39966 Black Ice
- Märklin 39400 Big Boy
- Märklin 38015 S 2/6
- Märklin 39924 Class 92
- Märklin 39029 18 314
- Märklin 38190 Sachsenstolz
- PIKO 50653 Class 93
- Roco 78022 Class 86
- Roco 79380 Class 038
- Roco 7120015 Class 10
- Märklin 39003 Class 01
- Roco 7120006 18 201
- PIKO 50902 Class 03
- Märklin 38205 Class 01.5
- Roco 7120017 Class 01.5
- Märklin 37066 Class 80
- PIKO 50745 Class 91
- Märklin 38206 Class 01.5
AC Diesel Locomotives
- Märklin 30601 Rio Grande F7
- PIKO 98552B PRESS Class 218
- PIKO 52436 ČSD Class 720
- PIKO 52482 MÁV M61
- PIKO 52407 V 160
- PIKO 52433 ČSD T 435
- Roco 7320039 Class 132
- PIKO 52657 Vossloh G6
- Märklin 26621 Bahnbau
- BRAWA 41163 Class 216
- Roco 7320060 Class 118
- PIKO 59728 Class 220
- PIKO 22006 NS Class 500
- PIKO 22063 Class 215
AC Electric Locomotives
- Märklin 39134 Lokomotion Class 151
- PIKO 59738 1,000th Vectron
- Märklin 39377 Class 101
- Märklin 36024 European Champion
- Märklin 36649 Germany 2024
- Roco 7520062 Taurus
- PIKO 51112 Class 101
- PIKO 21703 PRESS Class 140
- Märklin 39994 Class 194
- Märklin 39329 Vectron
- Märklin 39136 Class 151
- Märklin 38800 Class 186
- Märklin 36026 North America
- PIKO 21781 Class 114
- PIKO 21006 Class 184.1
Starter Sets and Train Packs
C Track and Digital Equipment
Decoders, Programmers and Accessories
Explore the system in more detail
Related guides for H0 centre-contact layouts
Frequently asked questions about H0 AC systems
FAQ about Märklin, centre-contact track and mfx
Is H0 AC the same as Märklin?
In model railway retail, H0 AC normally refers to the Märklin-compatible centre-contact system. PIKO, Roco, BRAWA and ESU also offer suitable vehicles.
Is a digital H0 AC layout really operated using alternating current?
The term AC is historical. A digital track carries an encoded signal. The decisive features are the centre pickup shoe and the digital protocol.
Can DCC be used on Märklin C Track?
Yes, provided that the command station and vehicle decoder support DCC. The locomotive still requires a centre pickup shoe.
Why does an mfx locomotive register automatically?
The decoder and a compatible command station exchange the vehicle name, function icons and additional data bidirectionally.
Which curve radius is suitable for H0 AC?
Many vehicles operate from approximately 358 or 360 millimetres. Long passenger coaches look considerably better on wider radii.
Can an H0 DC locomotive run on C Track?
Normally not without conversion. The centre pickup shoe, current collection, wheelsets and decoder must be adapted.
Can two-rail coaches and wagons run on an AC layout?
Frequently yes. Suitable AC wheelsets may be required for reliable operation through turnouts, feedback or interior lighting.
When is a booster required?
A booster is required when the power demand or layout size exceeds the output of the command station, or when separate short-circuit districts are required.
How does a Märklin contact track work?
One outer running rail is insulated. An AC wheelset reconnects it to the common return conductor when entering the section and therefore produces a feedback signal.
Mobile Station or Central Station?
The Mobile Station suits compact layouts. The Central Station additionally provides routes, feedback, networking and automation.
H0 AC combines robust track technology with convenient digital control
Further gauges, manufacturers, layout-building advice and digital topics are available in the central model railway guide.