# Using a relay to complete a connection on a DVD player



## Chewbacca (Oct 12, 2010)

It looks like you're using a solid state relay and if I remember correctly there is a voltage drop across the terminals. If there is, then this may be what's causing the problem. You might want to try a mechanical relay and that should work.


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## azirithdorr (Nov 5, 2010)

Chewbacca said:


> It looks like you're using a solid state relay and if I remember correctly there is a voltage drop across the terminals. If there is, then this may be what's causing the problem. You might want to try a mechanical relay and that should work.


Awesome. I'll give that a try - thanks Chewbacca!


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## EviLEye (Oct 21, 2012)

The side that you're attaching the DVD wires to needs to have power to drive the circuit within the solid state relay on the output side. See the schematic below for that relay you're using.

It looks like it needs power for the other side, which is why you're not seemingly getting a closure of a circuit like you're expecting with a mechanical relay where a contact switch is thrown and whatever is connected (common to normally open is now connected). 

The input and output sides are isolated and it appears the output is optically triggered.









Switching to a simple mechanical relay will easily solve this for you. As Chewbacca was saying, you'll have a minimal amount of current and voltage loss that's needed to typically close a relay.


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## azirithdorr (Nov 5, 2010)

Thanks Evileye - not only does that expand on what Chewbacca said but also my knowledge of relays in general. 

I'll switch of a mechanical relay as you both suggested. Do either of you have a 'standard' relay you like to use for things like this? Thanks again!!


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## BobbyA (Aug 20, 2010)

http://www.ebay.com/itm/G2R-1A-DC24...503?pt=LH_DefaultDomain_0&hash=item1c3546917f


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## Captain_hook (Dec 4, 2013)

G'day from Australia. First time here. I think that you have wired your relay back to front. Your DVD switch should be wired to terminals 1 and 2. The power signal should go to 3 and 4. Hope this helps.


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## Rev. Noch (Sep 2, 2008)

Here is the relay I'd use for this: TaydaElectronics 24V Relay. I've bought all kinds of stuff from Tayda, it comes fast and is exceptionally inexpensive. In my opinion Tayda is to Electronic components as Monoprice is to cables.


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## azirithdorr (Nov 5, 2010)

Thanks to both of you!

Out of curiousity: Why would you chose a SPDT relay instead of a SPST ? Just curious.


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## Rev. Noch (Sep 2, 2008)

SPST is just a basic on/off switch; where as a SPDT has both a normally open and a normally closed connection. As an example of what to do with that, light A is hooked up to the normally closed circuit of the relay and Light B is hooked up to the normally open circuit. When the relay is turned off, light A is on; then when the relay is turned on, Light A turns off, and Light B comes on.


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## azirithdorr (Nov 5, 2010)

Right - got that - so why would you use a DT for the 'play' button on a DVD player. I think I might be missing something, but I'm thinking that the 'play' button is 'on' when depressed and 'off' when let go of, so wouldn't that be a simple on/off switch?


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## Rev. Noch (Sep 2, 2008)

In your case with the DVD player and using the SPDT relay, you'd likely just hook the play button's contacts up to the Normally Open contacts and ignore the normally closed contacts; it'll work without problems that way.


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## azirithdorr (Nov 5, 2010)

10-4. Gotcha, thanks :>


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