4 Relay board resets Arduino

Hello,

I have a 5V 4 Relay board connected to an Arduino:

![](http://i.ebayimg.com/00/s/NTAwWDUwMA==/z/iuEAAOxye3BRyB0R/$(KGrHqZHJFEFGkQb5giYBRyB0RgrQw~~60_12.JPG)

Looks like each relay activation doesn't consume more than 20mA, but if I activate more than two at the same time, Arduino resets automatically after one or two seconds that relays stay activated. I don't know if it's a kind of auto-protection or similar.

But those auto-resets when three or four relays are activated at the same time only happen when I'm supplying Arduino through the V-in pin with 16Vcc (it's a power supply with 3 Amp, it should be enough by far). If Arduino is connected to USB works perfect and I can activate all 4 relays at the same time without resets.

Any idea of what happens? Are there differences in maximum output consumption if USB power supply is used or it is through V-in??

Thanks a lot in advance,

Dani

Hello.

It is interesting, you have the ground of relay board with the ground of Arduino?. Test only the outputs of Arduino without load and Look how it behaves.

The specs for the relays seems to be 70ma each when active. Along with the heat/power loss of dropping from 16 to 5 volts through the Arduino voltage regulator is probably causing thermal shutdowns… Try a lower voltage supply.

12V is the maximum suggested operating voltage for Vin, but the lower the better down to about 7V.

An external 7808 regulator on a heatsink could be used to bring that 16V to 8V, much more like it.

Or you could use a DC-DC converter. Lots of cheap variable output LM2596 based boards on eBay.

You must not run the relay board from the Arduino Vcc. You need a separate supply for the relay board, connecting the various Vin and Vcc to the Arduino outputs and “Vcc”, remove the link from “JD-Vcc” to "Vcc"and connect “JD-Vcc” and Gnd to the relay power supply. You do not need to connect Gnd to the Arduino.

Why are you using 16V ? That’s rather high for Vin pin. Have you tried 12V?

Paul__B:
You must not run the relay board from the Arduino Vcc. You need a separate supply for the relay board, connecting the various Vin and Vcc to the Arduino outputs and “Vcc”, remove the link from “JD-Vcc” to "Vcc"and connect “JD-Vcc” and Gnd to the relay power supply. You do not need to connect Gnd to the Arduino.

hej Paul,

I’m experiencing the same problem as the author, although it happens less frequent. Im only using a 5V DCC power supply feeding the Arduino. The VCC is coming from the Arduino.

I do not completely understand what you are explaining here. Can you explain in a bit more detail here how to wire the Arduino correctly to the relay board so it avoids resetting the Arduino?

Thanks!

Dries

OK, I note you reference a picture from my preferred supplier - I have generally found her reliable, as have many others.

Here is the circuit for each of the four relay sections: Note that for isolation, you connect "VCC" to Vcc on your Arduino, and each respective Arduino output pin to the chosen "IN" pin on the board. You then connect "JD-VCC" and "GND" to your [u]separate[/u] 5V supply for the relays, not the Vcc and GND on the Arduino unless you are actually supplying a closely regulated 5V power supply to the Arduino Vcc instead of using USB or its "Vin" or "barrel" jack through the on-board regulator.

Thanks for the quick reply! Ill try it like that!