HELP!!! I need a relay specialist!!

**1sthemi** · 01-21-2009, 10:31 PM

I need to know if any one on here are familiar with relays and how they work. I want to wire some up to have a latched on or off status with just the touch of 2 wires only! I have a setup of four relays wired to eachother which i have the on and off option but its with 3 wires though. If i touch the ground on one wire it wud make the relay atch on and if i touch the ground with the other wire it latches off. Is the a way i can use the ground witth just one wire to have a on and off function

**plcman** · 01-21-2009, 10:40 PM

Yep I will draw it up for you.

**plcman** · 01-22-2009, 01:33 AM

Here ya go!!

**Junior** · 01-22-2009, 02:21 AM

Do you see what I'm saying about this guy!?

**Hemi Wagon** · 01-22-2009, 02:48 AM

Originally Posted by plcman

Here ya go!!

Now can we see it in laymans terms..............LOL

**imahemi** · 01-22-2009, 08:43 AM

Cool cad drawing Ray... but im LOST... LOL

**radioactive** · 01-22-2009, 09:07 AM

Why not just buy a latching relay?

**1sthemi** · 01-22-2009, 10:23 AM

Is that setup for regular relays that have 87,87a,86,85 and 30 on them or is that a different relay setup? Below is what i thought mite had worked but i can only get it to work with 3 wires instant of 2

**plcman** · 01-22-2009, 11:30 AM

Originally Posted by 1sthemi

Is that setup for regular relays that have 87,87a,86,85 and 30 on them or is that a different relay setup? Below is what i thought mite had worked but i can only get it to work with 3 wires instant of 2

This circuit will work, with one button, I have transposed it to ladder I will make a cad of the equivalent drawing later.

This is how the above circuit works:

First we have to assign relay numbers to the above drawing.
Working from the left this will be R1 then R2 and so on.

Press the button and R1 energizes through the NC of R3, turning the 12v output on. The connection to the output is connected to the coil of R2 which latches R2 through the NO of R2 and the NC of R4. Now R1 is on, and because the output is latched with R2 it in-turn turns on R3 through the NC of R1 when the button is released and R1 is reset.

The unlatch is a little more complicated.
To unlatch the follow happens:

Now remember R3 is on with R2. So when the button is pushed again, the current now flows to the coil of R4 through the NO of R3 which is on. The diode blocks the current flow back to the output and keeps R1 from keeping R3 latched. This unlatches R2 and resets R2 to it's normal off state, because R4 NC is now open and the NO of R4 is closed this now holds R3 on and holds R4 on until the button is released, which then releases R3 and R4 and the circuit is reset.

I will post the Ladder equivalent later.

Raymond

**1sthemi** · 01-22-2009, 07:08 PM

Thanx your smart! I got it 2 work

**KStryker** · 01-22-2009, 07:39 PM

OMG is this stuff in english!!!

**plcman** · 01-22-2009, 11:09 PM

I am glad you got it worked out, also I posted the logic in ladder form for all to follow.

**plcman** · 01-23-2009, 12:22 PM

This diagram is easier to wire, all the relays have a common tie point for the coils, no grounding to activate. This causes a false trigger to happen, if you have a short to ground in the button circuit.

This is the same circuit as was posted but with some changes.

If anyone wants this in PDF format I can email it to you, I cannot PM it to you.

Raymond

**05Silver_C** · 01-23-2009, 01:32 PM

Umm... I cant remember how exactly to do it, and I dont have my electronics kit over here in Iraq with me, but Im pretty sure there is a much more efficient and simple way to make this switch by using an SCR