This document is dedicated to the infrastructure that you only need to set up once on a model railway layout. At CTC, this includes the power supply and the WLAN router.

Power Supply

Warning, an unsuitable power supply can irreparably damage the CTC modules!

For a model railway that is exclusively operated with CTC modules, we recommend purchasing a short-circuit-proof switch-mode power supply for direct current. At Reichelt, you can find the following recommendable table power supplies:

• MeanWell Table Power Supplies 90W
• MeanWell Table Power Supplies 280W

For those who prefer more flexibility, a laboratory power supply, such as PeakTech 6226, can also be used. They have the advantage of having a display for voltage and current but come with the following disadvantages:

• You can accidentally adjust the voltage and then destroy all CTC modules at once when you switch it on next time.
• A laboratory power supply typically does not switch off in case of a short circuit but only limits the current to an adjustable value.

If you plan to operate a mixed environment with analog or old digital systems, you must consider the following:

• CTC modules, in their delivery state, are neither suitable for alternating current (AC) nor for unfiltered direct current (DC). Especially old model railway transformers often deliver unfiltered direct current.
• CTC modules can be operated without concerns with so-called digital current (alternating current with approx. 10 kHz).
• If you use a separate power supply for your CTC modules, ensure there are truly no cross-connections between the CTC module and track power. A classic example here is the old Märklin turnout, where there is a cross-connection between the track and the turnout drive through the turnout lantern. With alternating current on the track, without a protective diode over this bulb, the CTC module will be destroyed.

Power Needs

When selecting a new power supply, the question naturally arises of how much current it needs to deliver. Here are some references:

• You can find the power needs of the CTC modules in their respective data sheets.
• Add the power needs of the simultaneously running locomotives.
• When the lighting is on, primarily good old bulbs play a crucial role.
• The turnout drives require a lot of power, but only for as long as they switch. Here, the inrush current is most relevant since CTC modules usually set turnouts to their default position at the beginning.

The simplest way to arrive at a reasonable value is to measure, especially the inrush current, and very generously round up the measured value.

To reduce the inrush current, the following options are available:

• In the config, set a default value for your turnouts that does not exist. However, the turnout will be in an undefined state from the CTC app’s perspective.
• In addition to the previous point, you can use triggers or press buttons to initialize the turnouts one after another. We will surely dedicate an article to this topic in the future. Until then, feel free to contact us if needed.

Alternating Current and Unfiltered Direct Current

It is fundamentally possible to use CTC modules with alternating current and unfiltered direct current. However, measures to protect the CTC modules must be taken before commissioning:

• All CTC modules must have a suitable capacitor for smoothing the input voltage. Current turnout modules and IO boards are already equipped with such capacitors.
• There must be no unprotected cross-connections between the CTC module and the track power (see below).

Protecting Cross-Connections

Here are some examples of cross-connections and how they can be protected:

• Old Märklin turnout (M-Track): Install a protective diode between the bulb of the turnout lantern and the turnout drive.
• Old Märklin locomotives, where one pole of the lighting is permanently connected to the housing: Install a protective diode between the bulbs of the front/rear lights and the connection on the CTC locomotive module H0a.

WLAN Router

Essentially, anything that supports 2.4 GHz and WPA2 encryption should work. The CTC modules and the CTC app must be able to communicate with each other without restrictions via UDP and HTTP. If the router also has 5 GHz, this frequency can be used for the tablet, smartphone, and PC, further increasing reliability, as all data packets must then pass through the router. Due to good experiences and widespread use, we have decided on the FRITZ!Box 4040 as the CTC Router.

When you order a CTC router, whether as part of the starter set or separately, it comes fully configured. Since we know the network name (SSID) and the network key (password), your CTC modules will always be pre-registered in your model railway WLAN. This service is why the CTC router is more expensive than a standard FRITZ!Box.

There’s fundamentally nothing against configuring your model railway WLAN yourself. Registering the CTC modules is straightforward, as described in Chapter 3 - Registering Modules to the WLAN. However, configuring the WLAN can be quite challenging. If you are unsure about this, we recommend the CTC router or the starter set.

Please understand that we generally cannot or can only provide limited assistance with the installation of unknown routers.

WLAN Router in the Garden

For outdoor operation, consider the outdoor suitability carefully.

For our garden railway, we use a CTC router (FRITZ!Box) in the house (e.g., in the locomotive garage) and extend the WLAN with an outdoor access point (TP-Link AC1200).