24V DC Transformer Rectifier Power Supply

24V Transformer Rectifier Power Supply

This 24V DC transformer rectifier power supply converts AC mains into a regulated 25.6V DC output, delivering consistent performance for a range of 24V DC devices. It is suitable for both new installations and retrofits where stable power is required, offering dependable supply in demanding environments.

Available in 1 Amp, 2 Amp, and 4 Amp models, the TRS range provides flexible options for small to large installations. Designed with installer friendly features, built-in protection, and a compact enclosure, this unit is ideal for applications where reliability is essential.

The RGL transformer rectifier power supply can be activated remotely by an external device, such as a fire alarm interface. When the fire alarm is triggered, it sends a signal to the interface, which then changes the state of its relay—either opening or closing its contacts, depending on the setup. This change sends a command to the power supply to shut off its 24V DC output. As a result, any connected devices are released, allowing them to close in line with fire safety requirements.

Key Product Features:

• 24-26V DC operating voltage
• 25.6V DC regulated output
• 1, 2, or 4 Amp models
• LED indicators: O/P, red LED fault, green LED mains present
• Full current to load
• Short circuit protection
• Switchmode technology
• Fused output
• Back EMF protection
• Dual inputs - external voltage or volt free
• Fail safe or fail secure output
• Multiple cable entry
• Cable retention points
• White powder coat finish
• Mild steel construction
• Instructions included
• Not suitable for use with back up batteries

Regulated Power for 24V DC Devices

Transformer rectifiers like the TRS range are widely used to power electromagnetic devices for fire doors. These include electromagnetic door closers with built-in hold open or swing free functions, as well as electromagnetic door retainers used alongside mechanical door closers. In such setups, the transformer rectifier acts as a door retainer power supply unit or a fire alarm door holder power supply unit.

Fire doors must be closed to provide effective resistance against the spread of fire and smoke. Electromagnetic hold open devices allow doors to remain open during daily operation for ease of movement and accessibility. When connected to the fire alarm system, they release automatically during an emergency so the doors can return to the closed position.

The RGL TRS Range: Choosing the Right Amp 

The TRS transformer rectifier range is available in three output ratings to suit different installation sizes and device requirements.

1 Amp: A-2401/4TRS

• 4 outputs
• Dimensions: 173mm x 120mm x 50mm

Ideal for powering a single electromagnetic door closer and has a compact enclosure for where space is limited.

2 Amp: 2402/4TRS 

• 4 outputs
• Dimensions: 200mm x 200mm x 65mm

Typically supports up to 10 door closers or similar 24V devices, depending on individual current draw.

4 Amp: 2404/8TRS

• 8 outputs
• Dimensions: 200mm x 200mm x 65mm

Suitable for larger systems, powering around 20 door closers or equivalent loads, subject to device specifications.

These figures are intended as general guidance. Always confirm the current requirements of each connected device to ensure the selected PSU meets the installation’s total load demand.

Compact, Installer Friendly Design

The absence of battery backup allows for a smaller enclosure, making the TRS range ideal for restricted spaces. Multiple cable entries and internal retention points help achieve tidy cable management. Installers can easily separate low voltage and mains wiring for ease.

For optimal performance, the PSU should be mounted close to the devices it powers, reducing voltage drop over long cable runs. This is especially important when powering multiple devices.

Power Supply for Demanding Environments

From door holder power supply units to access control devices, this transformer rectifier provides dependable 24V DC power. With flexible amp ratings, efficient switchmode technology, and protective features, it delivers the reliability needed for safety critical and control applications across commercial, healthcare, education, and industrial sites.

We stock a variety of power supply units, including 24V DC with battery back up capability and 12V DC access control PSUs. Discover our complete access control range or contact our technical team for advice.