PSU4 12-Output 12V DC Model Railway Power Supply Module

About the Product

The BLOCKsignalling PSU4 is a 12-output 12V DC model railway power supply module, designed to provide multiple stable 12V DC supplies from a single AC or DC power source. It is ideal for distributing power to model railway controllers, signals, detectors and other 12V layout electronics without requiring a separate power supply for every module.

The PSU4 automatically accepts a wide range of input voltages, from 5-25V DC or 9-16V AC, and provides 12 separate stable 12V DC outputs. Power can be connected using either the screw-terminal input or a standard 2.1mm DC jack, and DC input polarity does not need to be observed.

All 12 outputs share a total capacity of up to 1A and are protected by a self-resetting thermal fuse, providing convenient and protected power distribution around a model railway layout.

Key Features

• Provides 12 separate 12V DC outputs from a single power source.
• Ideal for powering multiple model railway electronic modules and accessories.
• Accepts both AC and DC input supplies.
• Wide 5–25V DC input range.
• Wide 9–16V AC input range.
• Automatically regulates the output to 12V DC.
• DC input is not polarity sensitive.
• Screw-terminal input for permanent wiring.
• 2.1mm DC jack input for compatible plug-top power supplies.
• Maximum 1A total output current shared across all outputs.
• Self-resetting thermal fuse protects against overloads and short circuits.
• Automatically restores power once a fault has been removed and the fuse has cooled.
• Built-in LED provides output and fault indication.
• No programming or configuration required.
  

12 Separate 12V DC Outputs

The PSU4 provides 12 individual pairs of 12V DC and GND terminals, allowing multiple model railway electronic modules to be powered neatly from one central supply.

This can simplify layout wiring considerably where several accessories require 12V DC, avoiding the need for numerous individual plug-top power supplies.

The combined current drawn by all connected equipment must not exceed the PSU4's 1A total output rating.

Universal AC or DC Input

The PSU4 can be powered from either:

• DC input: 5V to 25V DC.
• AC input: 9V to 16V AC.

The output is factory set to 12V DC ±4%, typically within ±2%. When using a DC input supply, polarity does not need to be observed.

Power can be connected using either the 2.1mm DC jack or the alternative screw-terminal input.

Do not connect both inputs at the same time. This warning is specifically shown on the manual's connection diagram.

Connecting the PSU4

The connection diagram shows all 12 individually labelled 12V DC/GND output pairs, together with the 2.1mm jack and alternative AC/DC screw-terminal input.

Each connected accessory receives the same regulated 12V DC supply, with the available 1A output capacity shared across all 12 connections.

Automatic Short-Circuit & Overload Protection

The PSU4 incorporates a 1A self-resetting thermal fuse to protect its outputs against excessive current and short circuits.

If the protection operates, the module's LED flashes approximately once per second. Once the fault has been removed and the protection has reset, the LED returns to steady illumination and power is automatically restored.

Technical Specifications

• Output voltage: 12V DC ±4% (typically ±2%).
• Number of outputs: 12.
• Maximum total output current: 1A.
• DC input: 5–25V DC.
• AC input: 9–16V AC.
• DC input polarity: Not polarity sensitive.
• DC jack: 2.1mm.
• Protection: 1A self-resetting thermal fuse.
• Status indication: On-board LED.

Documentation & Support

For detailed installation guidance, connection information and troubleshooting advice, please download the latest instruction manual:

User Instruction Manual