I am facing one problem with the relay. I connect my water pump and led to the relay which supports 3.3v and 5v. The led is connected to ac to dc converter, then connect to the main power supply. For the water pump connection, there was no something in between. The water pump was smooth, but the led was like it was working for few minutes and after that, the relay used to connect led was shorted. After I switched off the main power supply for led, the relay used to connect with led was not short again. Can anyone tells me the reason and possible solution. Btw, I connect 3.3v pin to the vcc in the relay. My boss does not want me to use 5v pin.

Once this is moved to the appropriate sub forum, you will be asked to provide a diagram and more details of your hardware.

@lukelouyu1029, your topic has been moved to a more suitable location on the forum. Installation and Troubleshooting is not for problems with your project :wink: See About the IDE 1.x category. [image] lukelouyu1029: and after that, the relay used to connect led was shorted. After I switched off the main power supply for led, the relay used to connect with led was not short again What does shorted / short mean.

[image] anon57585045: Once this is moved to the appropriate sub forum, you will be asked to provide a diagram and more details of your hardware. So .. can you please provide a diagram and more details (links to data sheets etc) of your hardware. [image] How to make a schematic you can post. Introductory Tutorials When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th…

ok, i will post it later. Thanks for reminding me.

@johnerrington This photo shows how I connect the relay. [IMG-2736] In actuality, I was planning to do this with the Digilent's Zybo board. Hence, the mainboard I used was not Arduino. But I did try with Arduino as well, I forgot to take photo of my arduino testing. Here is my schematic: [IMG-2739] Here is my code const int RELAY_PIN = 3; // the Arduino pin, which connects to the IN pin of relay // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin as an output. pinMode(RELAY_PIN, OUTPUT); } // the loop function runs over and over again forever void loop() { digitalWrite(RELAY_PIN, LOW); delay(15000); digitalWrite(RELAY_PIN, HIGH); delay(15000); } I connect my relay module with the AC to DC converter. The output of the converter has 3 channels. Each channels connect to LED strip. AC side is 240V with 2.1A current. DC side is 12V with 13A current. Here are pics of AC to DC converter [IMG-2737] [IMG-2740] Problem: The relay works for first one minutes. After that, the relay for the converter and led strip stops function. I used the multimeter to trace and I found out that the relay is shorted. (Like NC becomes NO. NO becomes NC) After one hours, the relay issue automatically solves. I just wonder why?

My first concern is the relay module +Vcc being drawn from the Arduino. There’s a chance the Arduino on-board 5V regulator is struggling, and may be overheating / shutting down over time. Is one of the outputs from the AC/DC supply is 5V, or are both fixed 12V ? Some have two separate output voltages. If you can find a chunky source of 5V, say 500mA - 1A, you might use that to power the relay module… The relay +v supply (you can even use batteries for testing), should be separate, but the 0V/Gnd must be common with the Arduino 0V so the relay control signal has a common reference between the two boards.

Thanks for you answer. My relay module vcc is tightly connect with Arduino 5V pin. I think the problem is not at Arduino side or Zybo side. The problem is sth to do with the ac to dc power supply for led. I tried the water pump as well and it was working smoothly. The led does not work as successfully as the water pump. The only difference between the water pump connection and led strip connection is there is ac to dc converter "between led strip and relay module". Meanwhile, I tried to connect the arduino with relay module (like how it shown in the schematic) when the cable of the led is not connected with relay module . It was also working well and I can hear the clipping sound. [IMG-2740]

You said the unit stops after a while… Let’s find out what stops… Add a couple of lines to turn the onboard LED (pin 13) on/off in sync with the relay. Then you can tell if it’s the Arduino or relay module that stops… Next, you can measure the power supply output voltage while it’s operating properly, and stopped…. you can speed up the cycle time if opit makes testing faster !

Hi, @lukelouyu1029 [image] lukelouyu1029: Problem: The relay works for first one minutes. After that, the relay for the converter and led strip stops function. I used the multimeter to trace and I found out that the relay is shorted. (Like NC becomes NO. NO becomes NC) After one hours, the relay issue automatically solves. I just wonder why? Thanks for the pics and circuit. If you remove power to your controller, does the relay open? If not it looks like the NO contacts have welded closed. How often do you turn the relay ON and OFF? You may need a snubber circuit across the COM/NO terminals to reduce arcing at the relay contacts. A switchmode supply, although rated at 2.1A input, usually has a surge current when switched ON, especially if the load is connected. What is the make and model of the supply, can you please post a link to where you purchased it and spec/data. Thanks.. Tom... :smiley: :+1: :coffee: :australia:

[image] lukelouyu1029: I found out that the relay is shorted. (Like NC becomes NO. NO becomes NC) This is what relay does when you power it.

Relay Shorted Reason

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johnerrington August 3, 2021, 6:57am 4

So .. can you please provide a diagram and more details (links to data sheets etc) of your hardware.

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Relay Shorted Reason

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