12v Relay problem

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rschuh54

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Hi guys , im using a 12v relay powered from the arduino uno and im getting signal and the light comes on but no clicking ? am i stupid or is the relay stuffed?
 
Sorry, scrub that .. .. .

It looks as though your trying to power a 12vdc Relay coil with 5vdc from the Uno .. ..
 
Musicmanager said:
Sorry, scrub that .. .. .

It looks as though your trying to power a 12vdc Relay coil with 5vdc from the Uno .. ..
Click to expand...
ive got the 5v from arduino going into the vcc on the relay, gnd to gnd. the 12 v dc plug is connected to the water pump with the negative split connected to NO and COM
 
Yes, but .. .. .. look what's written on the back of the relays .. the coils won't open with only 5vdc they need 12vdc
 
Yes .. .. .. ..

If you read the print on the back of the relay

12vdc is the coil - used to operate the switch

10A - 250vac - max load for the switch

15A - 125vac

you need a relay with a 5vdc coil

If you Google 5vdc Relay module there's loads of good examples

MM
 
Thankyou so much, very appreciated!!
 
Do you have a link to the relay board? It looks like it uses opto-isolators to switch the relay and Vcc may need to be 12V (on the relay board only).

Mike.
 
Diver300 said:
It needs 12 V on the Vcc connection of the relay board.

Do not connect 12 V to the Vcc connection of the Arduino. That will damage it. You have to disconnect Vcc on the Arduino from Vcc on the relay board.
Click to expand...
could i use a 5v relay instead and use the arduino?
 
rschuh54 said:
could i use a 5v relay instead and use the arduino?
Click to expand...
Yes, that should work.

The coils of 5 V relays will take more current than the coils of 12 V relays that can switch the same current. You would have to make sure that the overall current draw is not too much for the 5 V USB supply.
 
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