It's an "optocoupler" relay module operating at 12 Volt. Does this mean that 12 V is galvanic isolated from the arduino, that should control the relays? My first impression was: I am missing a separate ground for the relay control and for the arduino! However, after some study I discovered that you CAN operate the board with galvanic isolated 12 V and the arduino's 5 V. How? Don't use the straps!! So don't connect the 4 middle pins with straps to Ground or to VCC of the relay module, but connect these 4 pins to the arduino's ground! Now the 12V and the arduino's 5V are galvanic isolated! See photo!

It's an "optocoupler" relay module operating at 12 Volt. Does this mean that 12 V is galvanic isolated from the arduino, that should control the relays? My first impression was: I am missing a separate ground for the relay control and for the arduino! However, after some study I discovered that you CAN operate the board with galvanic isolated 12 V and the arduino's 5 V. How? Don't use the straps!! So don't connect the 4 middle pins with straps to Ground or to VCC of the relay module, but connect these 4 pins to the arduino's ground! Now the 12V and the arduino's 5V are galvanic isolated! See photo!

It's an "optocoupler" relay module operating at 12 Volt. Does this mean that 12 V is galvanic isolated from the arduino, that should control the relays? My first impression was: I am missing a separate ground for the relay control and for the arduino! However, after some study I discovered that you CAN operate the board with galvanic isolated 12 V and the arduino's 5 V. How? Don't use the straps!! So don't connect the 4 middle pins with straps to Ground or to VCC of the relay module, but connect these 4 pins to the arduino's ground! Now the 12V and the arduino's 5V are galvanic isolated! See photo!

Item as described and expected. Fast delivery and service from Banggood :)

Item as deItem as described and expected. Fast delivery and service from Banggood :) Thanks

Item as described and expected. Fast delivery and service from Banggood :)

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food seller

food seller

These relay modules are great for Arduino easy to use

These relay modules are great for Arduino easy to use

These relay modules are great for Arduino easy to use

Perfect!

Perfect!

Perfect!

Perfect!

Perfect!

Perfect!

very good!

very good!

very good!

OK.

OK.

OK.

very practical relay system, you can configure different devices without the need for so many circuits

muy práctico sistema de relay, podre configurar diferentes dispositivos sin necesidad de tantos circuitos

very practical relay system, you can configure different devices without the need for so many circuits

Thank you for the goods, I am very satisfied!

Thank you for the goods, I am very satisfied!

Thank you for the goods, I am very satisfied!