Hello Fernando. I already tried the relays with the ULN2803 and it seems that if it works. But now, the clock does not mark well it is as if voltage is missing, i come out as you can see in the photo. I connected and mark well the hour but after half a minute is as well. I have a doubt, have if you are going to be why do in the ULN2803 that I put it in the post connects the gnd capita there not to put the 5v to pin 10 of the ULN2803 is free?