5v Relay Module issue

Im trying to use 5v relay to making a programable switch for turning an led on and off (actually turning bluetooth module on and off). Actually im using 5v relays too often but now it doesnt work. Idk y i bought brand new relay module and its same with it. Its not getting triggered with 5v. I connected led's ground wire to switch part of the relay but when i give 5v to IN pin to turn relay on or off nothing happens. Its same always. (If i give 3.3v instead of 5v trigger led of the module does something like blinking but its not bright and its also doesnt conpletes the circut and it doesnt turn my led on or off) What should i do? Thanks for your help :slight_smile:

can you post a circuit diagram?

fnb111:
can you post a circuit diagram?

Classic relay connections

Actualy my question was this: Is there any problem with using relay for turning led on (using 5v and kind of low voltages not like light bulbs voltage)

Sorry but your picture leaves a lot to be desired but you need a resistor for the led. It’s possible that you may have burned it out without one.

What voltage do you have at + and -

Does the relay click?

wolframore:
Sorry but your picture leaves a lot to be desired but you need a resistor for the led. It’s possible that you may have burned it out without one.

What voltage do you have at + and -

Does the relay click?

Led is working without relay.(I know im supposed to use resistor but the relay doesnt even working im just testing it so no problem) Voltage is 5v from arduinos 5v pin. And it doesnt click. The market i bought from first tested the relay and then they sent it to me because this situation happened me yesterday and they send new one. (They tested it but as i say its same) So i mean that relay is not damaged and etc.

Still no solution.. :frowning:

zalimsavasci:
Still no solution.

Not surprising.

Vastly insufficient information.

Web link to the relay module you are using.

Web link to the LED you are using.

Specify what Arduino you are using to control this.

Paul__B:
Not surprising.

Vastly insufficient information.

Web link to the relay module you are using.

Web link to the LED you are using.

Specify what Arduino you are using to control this.

Standart relay module and classic led thats all
And im using arduino uno (original one)

OK, well that LED described as a "5mm transparent white LED" most certainly does not require a relay to control, but "It should be used with the necessary resistors for 5V and higher voltage values." as per the web site. This is never optional!

It would be quite foolish to use the "standard relay module" to control the LED because the relay module draws many times as much current (50 to 80 mA) as the LED does (20 mA). It is equally inappropriate to use this to control a Bluetooth module; if you were to cite the module in question, a more appropriate approach could be determined. You also need to state why you might wish to turn the Bluetooth module off - if it is with a view to using battery power then the UNO is the wrong approach also! :astonished:

It is also a simply silly relay module design. It employs an opto-isolator to no useful purpose as the way it is connected prevents it being used for isolation.


There are somewhat similar modules which have a two-way jumper on the board which allows the selection of active-HIGH or active-LOW operation and by removing the jumper and connecting to the centre pin, can be used as isolated relay controls. This is not such a one. :roll_eyes: