5V relay coil interface with arduino

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#1

Hello All, I am trying to integrate 5V relay coil with ratings as 7A 250V with arduino board. I have seen most of the relays with 12 V coil inputs. I have a relay which can be activated with 5V. I want to check if I can interface ULN2003A with arduino and 5V relay coil.

ULN2003A pin 9 talks about connecting this pin to 12V supply whereas my relay needs only 5V.

I created the interface as shown in the picture. With this I am able to activate the relay from arduino with the help of digital pin 3 from arduino.

Can someone help me to validate the attached circuit if it is correct way of doing or is there an alternative way to achieve this.

Regards, Rahul

#2

Sorry forgot to attach. Here is the attachment

Relay.png
Relay.png1600×1304 44.8 KB

#3

Yes, the ULN2003A will work with 5V supply on pin 9 (I've used as low as 3.3V).

If you're driving more than 1 relay, you need to use a separate 5V supply for the relay power to the coil.

#4

Yes, that's an OK use of the ULN2003. They are quite useful for general-purpose open-collector "Low Side Switch" purposes.

There are a LOT of small stepper motors that use this small ULN2003 driver board: HERE

That little board is very useful and you don't have to put stuff on a breadboard etc.. And it has LEDs that light on 4 channels.

OTHER: the schematic you will find HERE: shows a 5V relay with an optically-isolated connection to Arduino.

DISCLAIMER: Mentioned stuff from my own shop... ! But you can find them on ebay/amazon etc...

#5

I am using a 12V relay to drive a 5V motor but the motor is not working. The circuit I connected is same as Rahul's.(I gave 12V instead of 5V). Can someone help me out :(

#6