Ok I tried to run a search. but did not come up with anything.

Ok in a typical relay situation. You have a light that draws more current then the switch can handle. So relays are added to allow for this current to go thru the relay and not thru the switch or signal source. I get that. The problem is my project needs a larger current GROUND source.

I'm going to need to use larger bulbs on project of mine, which are going to require more current.

The way the system was made that I want to convert....The bulbs receive constant power. So a large power source is not a problem. But the signal wire is a ground that alternately closes the circuit so each bulb will light in sequence. Now I wanted to add a higher wattage bulb, but I think the current required would fry the negative signal wires.

So I was thinking about using a relay to provide a higher current ground source. Is there a way to make a relay work with a negative signal wire? Is there a special reversed relay I need to buy, or can the wires be swapped on a traditional relay.

Thanks! I hope this is not too out there for you!

 

most typical relays that i have worked with can be swapped.

is this something that can't be solved by a larger ground wire much like a stereo amp?

 

Well I thought of that...larger wire...BUT...
The problem comes with the signal wire...It goes to a box with a curcuit board. I know that can't take the higher current. And I'm not that good with curcuits boards...not that good, umm..ok I'm clueless...about them.

I had one box fail and I can't for the life of me figure out why. There is not a loose wire, but one of the signal wires is dead. So I got a new box and returned the old one. I had 3-4 people look at it and we could not figure it out! So from there I swore them off...I was not going to alter it.

I just needed a way to introduce a suffient ground for the bulb.

So how should I rig it?
Regular Relay wiring…
Standard relays have 4 prongs and are numbered as follows:
87: output to item
86: input (signal wire)
85: ground
30: power

Do I swap the ground wire (85) and the Power wire (30)?

Is that how you swap the relay from a power relay to a ground relay? I understand pretty well how relays work, but I'm not that good!

I wanted to ask before I attempted and fried something!

 

The problem that I see here is that when your present set-up wants to turn the bulb on, it drops to a ground potential to allow current to flow. When you want to activate a 12V relay, you send a 12V signal to the relay to activate the coil which in turn closes the switch and allows current to flow through it. In order for you to do this with your set-up you will need to have a constant power supply to the coil of the relay and then attach your signal wire to the ground side of the coil. When the signal goes low, current will flow through the coil and activate the switch and turn your new bulbs on. I think thats all you need. Hope it helps.

 

You are helping...I'm just slow to pick it all up...

Ok so tell me how that would work using the relay numbers/terminals...I'm almost following you. I'm understand the coil needs power...Sadly I have to see the wiring diagram in my head or I don't get it...darn us visual learners...

Ok what I have...the existing bulbs are actually X-mas bulbs...Pitiful I know.
They are welded on a printed curcuit...they have a power wire welded to the curcuit and this feeds to every bulb...Its hot all the time. Adding a ground to ea individual the bulb will light that individual bulb...yes

So I plan to ditch the printed curcuit and got to straight power wires to the bulbs...there will be no relay here, just a switch and fuse...I'm trying to upgrade to standard automotive lamp bulbs...not the 3 way bulbs...1157 or 1156 (25 watts I think)...whichever has the single filiment...but the ground current will need to be just as hefty as the power current coming in for teh bulb to burn bright...so... here is where I wanted to add the relay...because the ground signal current will be so weak running thru that board. I had hoped the relay could work like it does for fog lights but in the reverse...signal wire allows the signal to go thru to the ground side of the bulb and ground it so it lights...

Is that more clear....

Below I'm listing the relay i'm used to and plan to use... so you can tell me if I'm applying it right. I have to be sure I can apply the info to the application properly...
87: output to item
86: input (signal wire)
85: ground
30: power

So what I want to have for this to work...please tell me if I'm translating your info right...
87: is still the output to the lights (ground)...provides a ground potential to the bulb when signal wire drops to ground and stops the power signal from the coil going to the bulb?
86: is constant power because this terminal energizes the coil....and keeps the curcuit open when coil is energized...
85: Ground Signal wire here...?
30: My new constant ground?

I must have misunderstood something cause now I'm more confused...
please tell me how to apply what you have said...man I feel like an idiot...did I do it right...just not enough time to really sit here and let it sink in. I'm gonna have to sit and think about this more, but I have to leave work now to go meet a friend...

 

It sounds like you have got it. I think. I will attach some pictures to help explain. In this picture you can see the basic operation of a relay. 85 is Ground all the time. 86 is your small signal. In this case it must be a power signal because 85 is GND. When you send a signal down 86, the current flows through the coil and out to GND (85). This turns the coil into an electromagnet. This magnet pulls the switch on the right side closed. When the switch closes, power from 30 is allowed to flow through the switch to 87 where you have whatever you want to supply power to. See attached. Sorry for the poor quality pictures but it was the easiest way.

 

In your situation your signal wire does not send out a power signal but a ground potential. So this is what you do. On one side of the coil of the relay (86 in my diagram) you want to attach a constant power supply. This should be a low current supply so as not to over drive whatever you have supplying your ground signal. On the other side of the coil (85) you will attach your signal wire. Now what happens is that when your signal wire drops low and provides a ground path, current will flow from the power supply side (86) through the coil and out 85 which is your signal wire. This will engage the switch on the right side. You have power going to your bulbs and then a ground lead coming from the other side of the bulb. This ground wire should be attached to 30 so that when the switch is not engaged then the ground path for your bulbs is open and no current will flow and no bulb will come on. Attach a ground wire to 87. When you engage the coil of the relay the switch will close and allow your bulbs to have a ground path through the switch and out 87 to ground. See attached. Hope this helps.

 

Oh wow...it does make sense now...I was never really sure what when on in a relay...now that you have explained that it is so much clearer. I had no idea the switch was attracted to the coil via magnetism once it got a signal...dang...Ok I will give it a shot and let you know how it works! See darn us visual learners...the pics helped alot!

Thanks So Much...you have been an amazing help!
:hail: :hail: :hail: