power multiple relays without blowing my arduino

Hello everybody,

For a project with 4 RGB-strips, I want to control 12 5V relays like these:


But they draw 60mA each, that will burn my arduino.

The system will be build inside a promotiontrailer, powered by 12V-batteries.

I tried already with transistors but burned them (drawing to much current).

How can I solve this problem?


Dieter Belgium

Make a separate 5v supply using a 7805 voltage regulator ?


You should have bought 12volt relay modules. Now you have to drop 12volt to 5volt (1Amp) with a separate relay supply.

You can use a buck converter for that, or an 7805 regulator as Robin2 suggested. Note that a linear 7805 could dissipate ~7watt, and will need a heatsink when all relays are on. A buck converter does not need a heatsink.

Power the relay modules with 5volt(+) on the JD-VCC pin (jumper removed) and relay ground.

Connect relay VCC to Arduino's 5volt pin, and the relay inputs to Arduino outputs. Do_not_connect_relay_ground_to_Arduino_ground.

Power the Arduino (Uno?) with 12volt on the DC socket. Leo..

thx for your answers guys,

I bought nothing yet, just the arduino and the already mounted led-strips. So I can do whatever I want.

I didn't think about the choise that can be made with the jumper, now it is clear to me, I will buy those: https://www.banggood.com/nl/10Pcs-12V-2-Channel-Relay-Module-With-Optocoupler-Support-High-Low-Level-Trigger-For-Arduino-p-1142702.html?rmmds=mywishlist&cur_warehouse=CN

kind regards,


Hi, Welcome to the forum.

Please read the first post in any forum entitled how to use this forum. http://forum.arduino.cc/index.php/topic,148850.0.html

Can you post a copy of the circuit you tried?

Can you please tell us your electronics, programming, Arduino, hardware experience?

Thanks.. Tom.. :)