12V DC Power Supply with Universal Input PSU1

BLOCKsignalling PSU1 Universal 12v DC power supply


  • Multipurpose Power Supply to power a variety of features and modules
  • Wide range of acceptable input voltages
  • Accepts AC, DC or DCC inputs
  • Provides three separate stable 12V DC outputs
  • All outputs overload protected with automatic reset

This module fills the gap where a number of stable 12V DC power supplies are required for accessories, but only a single AC or DC power supply is available.

The input automatically adjusts for all power inputs in the range of 15V to 32V DC or 14V to 24V AC.

Each of the three 12V DC outputs has a 250mA self-resetting fuse, so in the event of a short circuit or overload, the power will be cut and then automatically reconnected after the fault has been cleared and the fuse has had time to cool.

On-board led indicates when the module output is present.


Output Voltage: Factory set to 12V DC +/- 4% (typically +/-2%)
Maximum Input Voltage: 32V DC or 24V AC
Minimum Input Voltage for stated Output Voltage: 14V DC or 14V AC
Maximum Current (per output): 500mA Connection

connecting dc power supply


Each output is protected against excess current and short circuits by self-resetting thermal fuses. In the event of the fuse operating due to a fault, allow up to one hour for the circuit to reset.

The output voltage is preset in the factory to 12V DC. The output can be adjusted over the range of 2V to 37V by resetting the voltage adjustment (remove the small amount of adhesive compound first).

For the correct output voltage, the input voltage must be approximately 2.5V above the required output voltage.

The output led is designed to operate up to 40V (although its output will diminish at lower voltages).