Using a wall charger to power relay

Other Hardware General Electronics
1

I have an arduino mega. I am trying to interface a 433MHz RF receiver and a 5v relay with my arduino but when I connect both at the same time, arduino is not able to deliver that much power. So I thought of powering the relay externally using a wall charger which is 5v 1A regulated.

When i try to power the relay using my wall charger it doesnt power up. I tried to power up an led circuit, it work well. So I dont understand what am i missing. Is it some resistor or something that i missed?

Thanks in advance.

2

When i try to power the relay using my wall charger it doesnt power up.

What do you mean "power up"? Are you saying the charger doesn't power-up or that the relay doesn't switch?

A relay shouldn't need anything near 1 Amp, so either something is broken, or something's wired wrong, or maybe it's not a 5V relay...

3

How are you connecting the relay? I hope it is not directly to the Arduino output pins.

Draw the circuit clearly on a sheet of paper and post a picture.

Weedpharma

4

And please tell if you use one of those ready made relay modules if you talk about "the relay". A relay != relay module

5

Here's the rules:

To ask a question, you give a web link to each object to which you refer, such as your receiver, relay and charger.

You then provide a complete diagram - or perfectly focussed and full daylight illuminated photograph - or both - of your setup.

And then you explain - in complete detail - the purpose of your project.

6

my bad! Let me explain..

Are you saying the charger doesn't power-up or that the relay doesn't switch?

The relay is not getting the power so its not switching. When i power it from the 5 volts of the arduino it works fine, but from charger it doesnt.

A relay shouldn't need anything near 1 Amp

Yeah its a 1A charger which means 1A is the max current that it can give. So if the relay needs 100mA then it will draw only 100mA. so I guess thats not a problem

maybe it's not a 5V relay

Its a 5V relay module, I have tested it on the same arduino board by powering it with the on-board 5V supply and it works. its just not working with the wall charger.

I hope it is not directly to the Arduino output pins

I m sry I forgot to mention it before, its a relay module. image below.

http://artofcircuits.com/wp-content/uploads/2014/05/2-ch-relay-module-1.jpg

I have attached the circuits. The first one in which the relay module is being powered by the arduino's 5V work perfectly fine. But in the second one, when its being powered by the wall charger, its not powering up and so its not switching.

Arduino_Relay_bb.png
Arduino_Relay_bb.png1755×1371 343 KB

Arduino_Relay_Charger_bb.png
Arduino_Relay_Charger_bb.png2592×1365 364 KB

7

Yeay... What have you learned about electricity? It flows in a circle! Can you complete the circle from the Arduino pin 7 and back? I can't, so just connect the GND of the charger to the GND of the Arduino :wink:

8

Yeah its a 1A charger which means 1A is the max current that it can give.

Have you checked the charger output with a multimeter to see if it is outputting 5v?

9

so just connect the GND of the charger to the GND of the Arduino

That what I was missing! thanks a lot!!