Where can I buy a 5 volt SPST relay? I found one at radio shack, but it has pins on the bottom. Im really looking for one that has spades on the bottom (like an automotive 12v relay). Or is there a harness I could buy to fit the pins?



This is gonna be used to wire something up on my car.

2/18/2011 5:04:31 AM

ebay, Amazon, etc

btw, if it's in your car, do you not have the 12v available to switch the relay?

[Edited on February 18, 2011 at 7:15 AM. Reason : .]

2/18/2011 7:13:34 AM

I do have a 12v source, but Im not sure if the ground can handle that. I dont know much about eletronics or eletrical wiring. The ground wire I have is for a 5volt source, so 12volts across the coin inside the relay, might be too much for the grounding to handle.

make sense?

2/18/2011 7:36:44 AM

Be more specific about why you think the ground would be insufficient for the relay. I have a hard time imagining any situations where the current through a relay alone would overload a ground wire/strap/connection. Additionally, is there no possibility of running an additional ground wire out to something else grounded and metal?

2/18/2011 8:25:28 AM

The ground wire i plan on using is actually a switched ground source. Its normally 5v and when i press a button it goes to 0 volts (which i assume is ground)

2/18/2011 8:57:20 AM

12v+ on one terminal and 5v+ on another would cause the relay to switch because of the voltage drop of 7 volts across the coil. I basically would have no control over the relay

2/18/2011 9:17:18 AM

That makes good sense, different than what I was imagining. Still no way of bringing in a 12v ground from the body or frame?

2/18/2011 12:34:41 PM

why don't you explain everything about what you are trying to do so that some people that know electronics can help you find the right solution.

2/18/2011 1:30:48 PM

how will i control it with my button? I can get a ground off anything, i want my switched 5v\ground to control the relay.

2/18/2011 1:46:01 PM

^^

2/18/2011 2:20:14 PM

^^^ I am still at a bit of a loss for what you're attempting to do here, but you may just need to get the 5v relay you already found and either solder some leads directly onto it, or use a perfboard and make yourself a little breakout for it.

2/18/2011 2:25:36 PM

Quote :

"i want my switched 5v\ground to control the relay."

So if I get this right, you have a button that either has 5v or Gnd on it's output and you need the ability to switch 12V? Or you just need to switch 5v?

2/18/2011 4:58:12 PM

^ he needs to just explain what he has and what he wants so we can give him the right solution without burning up his car

2/19/2011 6:47:52 AM

I have a button. The wire leaving this button is 5 volts. When I press the button it switches to 0 volts, which I assume is ground. I have another wire that varies from 0-4.5 volts based on throttle position. This varying wire is supposed to be connected to another switch. I want to install a relay where I can control when this varying signal actually reaches the other switch. So i plan on doing a spdt relay. hook the 5volt button wire to one side of the coil and ground to the other. So in normal state the relay is active. when i press the button the relay with close and switch to the other throw. The other throw will allow the varying signal to pass through to the switch that it is already connected to

2/19/2011 7:26:03 AM