Dual 12V Switching Relay Expansion Module

Dual 12V Switching Relay Expansion Module: Two Channels for Safe 12V Control

The Didactum Dual 12V Switching Relay Expansion Module is a compact switching and power supply unit with two independent channels for controlling 12V DC loads. Via two dry contact inputs, the module can be triggered by dry contact outputs of a Didactum monitoring system or by third-party controllers, buttons, or sensors, and then reliably switches electronic locks, LEDs, solenoid valves, fans, sirens, or relays.

Each of the two channels (A and B) provides a complete interface with 12V DC power output, potential-free relay output, and ground connection. This allows external devices to be connected directly and switched on and off specifically via the respective dry contact input – for example, when a monitoring system switches a dry contact relay during an alarm and thereby activates an electronic door lock, a siren, or a warning light.

Thanks to its robust construction, galvanic isolation between the control and load circuits, and simple mounting on a 35mm DIN rail, the module is suitable for professional continuous operation in access control systems, building automation, server cabinets, and industrial control applications.

Two Independent Channels, One Compact Module

The relay module has two dry contact inputs (A and B), via which the two channels can be triggered independently of each other – for example, by a dry contact relay of a monitoring system, a button, a card reader, or an access control system. Each of the two outputs simultaneously provides a stable 12V DC supply as well as a potential-free relay contact and a ground connection. The internal relays ensure safe electrical isolation between the triggering control signal and the switched load, which is particularly important in safety-critical applications such as access control.

Use with Didactum Monitoring Systems and Third-Party Controllers

The relay module can be connected to the dry contact outputs of Didactum monitoring systems that have corresponding dry contact outputs and is then automatically triggered in the event of a corresponding alarm or event.

Since the module is controlled via two simple dry contact inputs, it can alternatively also be operated independently of a Didactum monitoring system and combined with controllers, buttons, or sensors from other manufacturers.

Typical Application Examples

• Control of two independent electronic door locks in access control systems, triggered via keypads, RFID readers, or access control panels
• Smart home automation: Switching 12V LED strips, irrigation valves, or fans via sensors or automation hubs
• Alarm and notification systems: Triggering sirens or 12V warning lights in the event of motion, door, or gas detectors
• Cabinet and rack control in IT and telecommunications: Supplying 12V fans, locks, or status lights in server cabinets
• Industrial and commercial plant control: Switching 12V pumps, solenoid valves, or actuators
• Emergency and safety systems: Via an emergency button, a connected device is triggered via dry contact, such as unlocking a door or activating an emergency light

Mounting on the DIN Rail

The relay module is designed for quick mounting on a 35mm DIN rail.

1. Position the housing at the top edge of the DIN rail
2. Click the housing down into the DIN rail until it sits securely
3. To disassemble, release the wall/DIN rail mounting clip with a screwdriver and pull the housing outward

What is Included in the Delivery

Please check the scope of delivery for completeness upon receipt and report any missing or damaged parts to your supplier immediately.

• Dual 12V Switching Relay Expansion Module1 piece
• Power supply, 12V, 1A, 3.4×1.35 mm1 piece
• Terminal block, 6-pin, 3.81 mm1 piece
• Terminal block, 2-pin, 3.5 mm1 piece
• Terminal block, 4-pin, 3.5 mm1 piece
• DIN rail/wall mounting clip2 pieces

Why This Relay Module is the Right Choice

Frequently Asked Questions