Creasol DomRelay2 is a compact module, 43x24x25mm, within 2 relays with 12V 200mW coil, 250V 5A SPST contact with special material designed to prevent contact welding due to excessively high surge current load (capacitive loads or tungsten lamps).

Contacts are protected from overvoltage by metal oxide varistors; coils are protected from overvoltage by free-wheeling diodes.

Relay coil should be driven at 12Vdc 17mA: using DomBusTH or DomBus12 modules it's possible to drive relays using a lower power system, consuming less than 1/4 of nominal power.

Features

• 2 relays, that can be driven by domotic modules like DomBusTH or DomBus12 or any other device with 12Vdc 17mA output
• sensitive coil, consumes only 200mW @12V
• Single-Pole Single-Throw outputs (normally-open contact)
• 250Vac 5A contact rating, or 30Vdc 5A.
• special contact material to prevent contact welding due to excessive load current (capacitive loads)
• overvoltage protection with metal oxide varistors
• 3.5mm pitch input terminal block, with 12Vdc common and 2 inputs suitable to be connected to open-collector/open-drain outputs.
• 5.0mm pitch output terminal block.

Application notes

Layout

Connect 12V terminal block to the power supply 12Vdc.
Connect each relay input to a module output that pull down the line to ground, like an open-collector or open-drain output.

For example it's possible to drive this relay module by DomBusTH  and DomBus12 , RS485/Modbus modules for Domoticz that also have a useful feature that permits to drastically reduce the relay power consumption to about 1/4 of the nominal coil power.

Using DomBusTH in a bedroom to control roller shutter motor by a twin button.

DomBusTH is a home automation module within temperature/humidity sensor, 3 leds, 4 I/Os and 2 open-drain outputs.

The open-drain outputs are suitable to drive relay coils, so they can be connected to the DomRelay2 module to control, for example, a roller shutter motor to open/close shutters/blinds/curtains.

Similarly, DomBus12 is another home automation module with 7 I/Os and 2 open-drain outputs, which are also suitable to control a relay module as DomRelay2.

Both DomBusTH  and DomBus12 have a useful feature that permits to drastically reduce the relay power consumption to about 1/4 of the nominal coil power.

Using DomRelay2 to get 1 or 2 remote controlled sockets

The following picture shows how to use the compact DomRelay2 module to control 1 or 2 sockets.