Electrical Circuit Help Needed

[Spudland_Dave]

Ok...heres the deal...working on a diverter setup. I kinda have to use a SPDT switch cause its the only factory switch I could find...working on a DPDT switch which would do away with the need for this post, but having a "Factory Looking Install" Trumps the switch issue..LOL
Here's what needs to happen....

When No Power is applied to the block, the Green Hyd Circuit is "Live" (Off Position on switch)
When I want to use either the Yellow or Blue Hyd Circuit, I need to also energize the green which shuts that port down.
How?...I Realize the diagram is unfinished...

 

[kennyd]

 

[schmart]

You can use 2 diodes to isolate the circuit that must be powered in both positions...

Hopefully I can get this to paste an image. It is not nearly as pretty as yours but hopefully you can tell what I mean.

--Rick

 

[elad]

I think Kenny D has the right answer.

 

[ampsucker]

you, my friend, have drawn a SPDT switch, but described a combination of things that can't happen with your diagram.

if you truly have a SPDT switch, you have 12 volts feeding the center terminal and on the down throw in your diagram, you energize green and yellow. this is not really the "off" position but rather throw "A". on throw "B", or up in your diagram, you energize blue.

here's the part i don't understand:

"When I want to use either the Yellow or Blue Hyd Circuit, I need to also energize the green which shuts that port down."

Why is this? Is there a latching relay in the circuit somewhere or some other reason you have to energize and re-energize green to shut it down? The way it's drawn and with the switch you describe, once the switch is moved from position "A" to "B", anything hooked to "A" is no longer energized.

The answer would determine what you need to do. A complete diagram using regular circuit schematics whould be helpful.

Circuit Schematic Symbols

amp

 

[3RRL]

Not 100% sure, but it would seem to me to add a wire from the green to the blue (+) just like you have the yellow and blue drawn in your diagram. When you activate the switch to activate the blue, the green gets activated also. Same with the yellow and green. Like I said, I'm not 100% sure so I hope someone will verify before you do it.
I was told by a friend to put a diode between the + and - of each switch to extend the life of the switch. Make sure the band is on the + side of the terminal.

 

[Treemonkey1000]

Wasn't sure of your explanation of what you were doing. Would these work?

 

[TedLaRue]

Dave,
From your description, I can see how Schmart's came up with his schematic. But then if that is what you want, you might as well just hardwire +12V to the green since it's always on. I think that's what's confusing us. We're not sure what you want.

1) Are the green, yellow, and blue boxes supposed to represent solenoid valves?

2) Does this SPST switch have a center-off position by chance?

Here's my guess at what you want:

Switch thrown to position A:
Only green is energized.

Switch thrown to position B:
Yellow and Blue are energized as well as Green.

Switch in the center:
Nothing energized.

If that is what you want, the attached schematic would work for you.

If not, please clarify.

You can buy diodes at Radio Shack. Just make sure the forward current rating (usually written I/f (the f is a subscript)) is high enough to carry the amperage drawn by your solenoid valves. I have no idea what that value is, maybe 1 amp? Higher is ok and safer. This one handles 6 amps and should be more than adequate at $2.49 Radio Shack Catalog #: 276-1661.

If you want to install the diodes suggested by 3RRL's post to protect your switch from arcing, use the $0.99 Radio Shack Catalog #: 276-1102 (1N4003), connecting one across each of the solenoids with the banded end NOT on the side connected to ground.

PS: I think where you have -12vDC in your diagram you probably meant 0vDC (unless you have a 24 volt system).

 

[GuglioLS]

You can use 2 diodes to isolate the circuit that must be powered in both positions...
--Rick

Rick has it right,
This switch is powering solenoid's, right?
If that's the case then I would add two diodes across both sides of the switch to +12 to prevent arcing across the switch contacts when the switch is opened (turned off). It will protect the switch contacts from burning over time.




Larry

 

[Spudland_Dave]

Sorry to confuse you guys...I appreciate the help thus far! Lemme see if I can answer some questions so we're on the same page.

What I'm trying to do is to wire up the 3 bank Hydraulic Diverter from Surplus Center.....Port 1 (Green in my drawing) on that block is prioritized...meaning with no 12v power to it, oil will flow thru it. So when I use either of the other ports (yellow or blue) I would need to energize the green port which shuts flow off to it and diverts it to either the yellow & blue ports.

1) Are the green, yellow, and blue boxes supposed to represent solenoid valves?

Yes

2) Does this SPST switch have a center-off position by chance?

Yes, its a Center off Switch... On-Off-On to be exact


Switch thrown to position A:
Only green is energized. - No, I would need Green & Yellow Energized

Switch thrown to position B:
Yellow and Blue are energized as well as Green. No, I would need Green & Blue Energized

Switch in the center:
Nothing energized. Correct

 

[ampsucker]

ok, so if we understand this right:

switch is off, green is on (due to priority, it is on when no voltage applied).

switch in position "a", green is energized shutting it off and yellow is energized turning it on.

switch in position "b", green is energized shutting it off and blue is energized turning it on.

if that is what you need, larry's diagram is essentially correct. i wouldn't think you would need the diodes, though, unless your switch is seriously undersized for the solenoid current draws.

 

[Spudland_Dave]

You got the operation of the switch exactly correct.

Switch is rated for 20 Amps @ 12v and each solenoid draws 1.5 Amps according to SC...so even running 2 at a time thru the switch shouldnt be an issue.

 

[Wayne County Hose]

US - Electronic Components Distributor | Newark.com. <------- I would find a DPDT switch that would satisfy the factory look. Other than that, I would use 2 relays, energize one for green/yellow, energize the other for green/blue. You can't put just any diode in that circuit.

The diodes Larry drew in function like suppressors and many times are factory installed. They help to isolate the rest of the tractor's electronics from the electrical noise of the coils.

 

[Spudland_Dave]

I would find a DPDT switch that would satisfy the factory look.

Well, I found the exact factory MFG/Source for the switch, but problem is nobody has em in stock and one of the sources/electronic warehouses want a minimum order of 12....
Wouldnt be bad if I knew people out there would want some "Factory" Deere Switches without any printing...

 

[Wayne County Hose]

Well, I found the exact factory MFG/Source for the switch, but problem is nobody has em in stock and one of the sources/electronic warehouses want a minimum order of 12....
Wouldnt be bad if I knew people out there would want some "Factory" Deere Switches without any printing...

Can you post a pic? Maybe a mfg catalog/part #? I have a few aftermarket electronics sources.

 

[gemini5362]

I think kenny d has the right answer also. I cannot see his diagram that well to make sure. Basically get two diodes. Depending on how much current the solenoid powers make sure you get them to handle that much current. hook the +12 volts to the center of the switch. Hook the yellow solenoid to one side of the switch. hook a diode up with the yellow wire so that the banded end is pointing away from the switch. hook the blue wire up to the other side of the switch hook another diode up with the blue wire so that the banded end is pointing away from the switch. you now should have a switch with a yellow wire and a diode on one side the diode has the banded side not hooked to anything. The switch also has a blue wire and a diode hooked to the other side. the banded end of this diode is also not hooked to anything. Now then hook a piece of green wire (maintaining color code here but any color could work) to the unconnected end of the two diodes. This wire needs to go to both diodes. Hook your green solenoid to this wire. hook the other side of all three solenoids to a ground wire and you are done.

 

[Superduper]

Forget all the diode routes. All you need to do is use that SPDT switch to power ONE SINGLE DPDT RELAY. That is all you need. Problem solved.

Switch position A will power Relay position A, which has TWO POLES!
Switch position B will power Relay position B, which has TWO POLES!

Does that make sense to anyone?

 

[Spudland_Dave]

Super Duper.....Thats exactly what I needed....looking at it and thinkng about it, Its my best bet...THANKS!

 

[Wayne County Hose]

Forget all the diode routes. All you need to do is use that SPDT switch to power ONE SINGLE DPDT RELAY. That is all you need. Problem solved.

Switch position A will power Relay position A, which has TWO POLES!
Switch position B will power Relay position B, which has TWO POLES!

Does that make sense to anyone?

This would have one set of coils always energized. 2 relays as described in my above post would only energize the coils when they are needed.

 

[Spudland_Dave]

This would have one set of coils always energized. 2 relays as described in my above post would only energize the coils when they are needed.

Thats the route I was thinking before SuperDuper's post... Get 2 DPST Relays and only energize them as needed...
Hmm...I think I'm gonna be making a Mock Up using some lightbulbs in the basement before doing anything on the Tractor...