0
\$\begingroup\$

I am making my own little power-failure warning system. So when the power goes off a LED and buzzer goes on.

Right now it looks like this: https://i.stack.imgur.com/IzGrt.jpg (Sorry for not making it the right way)

But... The coil is not moving. It's in "off" mode the whole time. And that is kinda strange.

So when I was searching for the error I connected the coil to a 9V battery (even if it's a 5v relay). Then the coil was suddenly moving. So I changed the voltage on the adapter to 9v. But still no reaction.

And YES the current is going trough, because I placed a LED after to see if there was current at all. And it was.

So what could be the problem?

Best regards fiskarn

And well again I connected a LED to the relay-circuit and it was lit. So there's current. Also measured the voltage to 4.9 wich would be enough? But as I said I even tried with 9V and 12V.

Also tried on 3 different relays with the same results.

\$\endgroup\$
6
  • \$\begingroup\$ Different relays have different activation voltages. Are you sure you are providing enough voltage? Is everything connected correctly? Also, please make an attempt at a better circuit. The one you have provided doesn't really clear anything up. \$\endgroup\$
    – Envidia
    Mar 16, 2017 at 23:41
  • \$\begingroup\$ Yes. Well as I said this relay is 5V. And also it works when connecting to a 9V battery, but not when changing the adapter to 9V (or even 12..) Don't really know how to make right circuit examples. But well there's the relay and when OFF I want the LED connected to the battery to light. \$\endgroup\$
    – fiskarn
    Mar 16, 2017 at 23:57
  • \$\begingroup\$ Assuming a standard relay footprint, your drawing only shows one connection to the coil. The other is open. \$\endgroup\$
    – user133493
    Mar 17, 2017 at 0:27
  • \$\begingroup\$ Isn't it the coil terminals (4.bp.blogspot.com/-hJ9A5YS7bsI/TyKZIRsbr3I/AAAAAAAAAyw/…) that are the two pins activating the coil? And the one between them are the ground for the N/C and N/O? Or how should I connect for the coil to activate otherwise? \$\endgroup\$
    – fiskarn
    Mar 17, 2017 at 0:36
  • \$\begingroup\$ Oh one of those. It would have been better to give this information at the start. Moving on, your diagram doesn't show a current-limiting resistor for the LED. Do you have one? \$\endgroup\$
    – user133493
    Mar 17, 2017 at 0:46

1 Answer 1

0
\$\begingroup\$

Solved hehe. Since the LED (wich is a 12v LED) was in series with the relay it didn't work. Changed to parallel and now it works just fine!

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.