Using ulm2803apg to activate relays

Hi there!
I am trying to activate a relay with arduino using a transistor array ulm2803apg with No success.

It might be something silly and I cannot figure out what is wrong.

Attached is a photo of what I am doing. Reviewing and reviewing it looks OK to me but I might be "loosing" something....

Any help will be appreciate!

IMG_5037.JPG

Well for starters there is no ground between your breadboard and Mega (all grounds connected).

What is the rating of your relay? Is it 5 volt for the coil? Can it be activated just by hooking it up to the power rails (5V)?

justone:
Well for starters there is no ground between your breadboard and Mega (all grounds connected).

I joined the grounds but....... I fried up the protoboar power suply.... :confused: Not it works only the 3v rails.....

I have checked the max power from the protoboard power supply is higher than the coil consume, so I do know what is wrong.......

justone:
What is the rating of your relay? Is it 5 volt for the coil? Can it be activated just by hooking it up to the power rails (5V)?

The relay is 3v coi. I have connected it to both rails (3v and 5v) and it works on both 3v and 5v

irrintxi:
I fried up the protoboar power suply..
I have checked the max power from the protoboard power supply is higher than the coil consume, so I do know what is wrong.......

You're not the first one it happened to.
Proto board power supply sellers leave vital information out of the specifications.
Max current from the 5volt rail can only be drawn if DC jack input voltage is <=6volt.
On e.g. a 12volt supply, max current draw from both 3.3 and 5volt rails together is less than 100mA.
Leo..

wow!!!!
Thanks for that clarification wawa! Really important information missed.....

I have used and external 3v power suply (more powerfull) and now it is working

Thank you all!