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Relay on vocores GPIO

Posted: Sun Jan 11, 2015 2:33 pm
by jonas
Hey there,

im working on a project with vocore, where i must connect a relay to the gpio of the vocore.

Now I want to know which relay I should use. So basically if I need a transistor between the gpio and the vocore or how much current I get from the gpio.
Im a noob in terms of hardware, I hope you could help me.

Cheers,
Jonas

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 12:57 am
by Vonger
My suggestion: connect the relay to optical coupler, then connect optical coupler to VoCore gpio, that will lower the risk and make it more stable.

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 9:14 am
by Greenwire-Elektronik
Jonas, Vonger is right - basically you should never directly control a relay with a gpio. If you give us more details we might can help you further. Please think of the free-run diode in your circuit to waste the coil energy after switching.

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 12:10 pm
by Pyrofer
Here are the details on the basics of doing this.

http://www.electronics-tutorials.ws/blo ... rcuit.html

It wouldn't hurt to sling in an opto-isolator too of course.

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 12:28 pm
by Greenwire-Elektronik
Ah, it is called flywheel diode in english - good to know :D

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 1:13 pm
by jonas
okay, I'm shure I will not connect the relay directly to the vocore :D
after a little googling for gpio and relays on the raspberry pi I found this plan: https://www.raspiprojekt.de/images/anle ... relais.gif

This should control 2 leds with a relay.

Do you think this could work too on the vocore? Or should I exspect problems with that?

Cheers,
Jonas

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 2:29 pm
by Greenwire-Elektronik
What exactly do you wanna do? And how is your post here related to this thread?

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 3:24 pm
by jonas
I want to do exactly what the plan says.
So, control 2 leds with a relay.
And because I'm not experienced on the hardware part and got nearly no knowledge there, I'm trying to find out if exactly this setup would work with the vocore.

The other post I made was because I've read the thread and searched for these solid state relays and this was what I found.
If you say I would go better if I take a solid state relay, I will do so, but for me it would be easier to just use the setup from the raspberry pi project,so I didnt need to care much about the hardware part.

Cheers,
Jonas

EDIT: deleted the post you mentioned above, I thought It would be better if I this problem is only in one thread

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 3:45 pm
by Greenwire-Elektronik
I am asking because for LEDs you normally do not use a relay. So i asked for more details - next time my question will be more precise, sorry.

So what kind of LEDs do you want to control? Which Voltage do you want to use to power the LEDs?

Re: Relay on vocores GPIO

Posted: Mon Jan 12, 2015 3:59 pm
by jonas
so basically I want to know how I should use a relay in connection with the vocore for future projects. To turn devices on and off.
And for training purposes I want to try that out with LEDs.

I thought if I ask this question I could use the relay setup nearly everywhere.

And to the LEDs:
Im not shure now, maybe 5V?

Cheers,
Jonas