The True Electrical Unicorn Hiding in Atlantis

[JackE]

I have been searching for a 12 volt 3 way switch that seemingly does not exist.

I want a switch that is off in the down position, on in the middle position, and does the spring loaded momentary off in the up position.

Such a simple thing, but does not exist, at least not in my internet searches.

Anybody have any ideas? Is it there and I'm just not seeing it? Or is it easy to switch wires on a on-off-momentary on switch and I'm just over thinking it?

I know I can use a series of relays to achieve what I want to do, but this would be so much simpler, take up less space in the electrical box, and be cheaper too.

[CHEESE_WAGON]

The question is, are you controlling one circuit or two? I assume DC since you mention 12V.

[Rucker]

Originally Posted by JackE

I have been searching for a 12 volt 3 way switch that seemingly does not exist.

I want a switch that is off in the down position, on in the middle position, and does the spring loaded momentary off in the up position.

Such a simple thing, but does not exist, at least not in my internet searches.

Anybody have any ideas? Is it there and I'm just not seeing it? Or is it easy to switch wires on a on-off-momentary on switch and I'm just over thinking it?

I know I can use a series of relays to achieve what I want to do, but this would be so much simpler, take up less space in the electrical box, and be cheaper too.

I have to ask, what is the application? For instance, my Onan Genset has three positions, off, on, start. Off is momentary on (shorts the run circuit), on (allows the run circuit), and momentary on (charges the ignition circuit).

[kazetsukai]

Originally Posted by JackE

I want a switch that is off in the down position, on in the middle position, and does the spring loaded momentary off in the up position.

Single appliance: Sounds like an ignition switch + a single relay will do the trick. You wire the appliance in through N/C and the "on" position, then the relay control leads through the "start" position. Turn the key (there are keyless variants) on, your appliance is on. Turn the key to start (momentary) the appliance turns off, let go its back on. Turn the key off, appliance off.


Alternatively an on/off switch wired in series with a momentary switch or button will "do" the same thing, although I imagine both are not quite what you are looking for. Apologies if this is not of help for your situation.

[BeNimble]

Originally Posted by kazetsukai

Single appliance: Sounds like an ignition switch + a single relay will do the trick. You wire the appliance in through N/C and the "on" position, then the relay control leads through the "start" position. Turn the key (there are keyless variants) on, your appliance is on. Turn the key to start (momentary) the appliance turns off, let go its back on. Turn the key off, appliance off.

Brilliant!

[JackE]

Sorry, I was at the end of my work day when I posted and my relief person showed up early so I had to wrap it up quickly and didn't get to finish my thought process.

Since I am changing all my exterior lights to LED, I am also planning on separating the upper clearance lights to their own circuit. It may have been like this originally but there were so many of the pull switched melted and not working that I am replacing everything and isolating each circuit so I know where every wire in the panel goes. Ideally I would like a single on-off toggle to match all the other new toggle switches I'm adding, for this circuit. Inside that circuit I would like a lighted push button switch that will momentarily interrupt the circuit for the pass/flash thank you. More simply, if I can find a toggle switch that is off in the down position, on in the middle, and momentarily off in the up position for the flash, that would be good enough.

I know how to make it work the way I want it to using relays, it just adds more wiring and confusion down the road a few years when I'm older, more forgetful, and can't remember what the heck I did in that electrical panel.

I just can't believe in all the different switch use patterns I have seen, there is no 'off-on-momentary off' combination switches.

[family wagon]

I can't quite tell if you want a toggle, a lighted push-button, or a combination..? Anyway, Digi-Key and Mouser both make searching for a switch pretty easy. Digi-Key uses the notation Mom-On-Off to describe that switch function; Mouser writes it (On)-On-Off. Digi-Key offers Carling 6GG5B-73; Mouser has a couple other styles of the same Carling switch.

[JackE]

Originally Posted by family wagon

I can't quite tell if you want a toggle, a lighted push-button, or a combination..? Anyway, Digi-Key and Mouser both make searching for a switch pretty easy. Digi-Key uses the notation Mom-On-Off to describe that switch function; Mouser writes it (On)-On-Off. Digi-Key offers Carling 6GG5B-73; Mouser has a couple other styles of the same Carling switch.

That is close, but still isn't quite the right animal.

Here is what I'm looking for;

Option 1: On-off rocker switch. On position turns on clearance lights and a lighted push button on the switch panel right next to the rocker. When I push the lighted button, the clearance lights go out as long as the button is held in. Release the button, they come back on. Pushing the button in and out allows me to flash the clearance lights without having to flip the rocker switch on and off.

Option 2: A 3 position toggle switch. Down position is off, middle position is on, up position is off but spring loaded to return to the middle position, allowing me to easily flash the lights without forgetting to flip them back on.

The most common switch is middle position off, down is on, and up is momentary on (spring loaded to return to middle, off position) I know this is how big trucks use to be set up, at least 20 years ago when I did a little driving, but I want it simple enough if my wife ever has to drive, I don't have to give her an hour lesson on what every thing on the switch panel is and does. If she ever drives, it will be so infrequent I would have to reteach her every time.

[Rucker]

Ah, now it makes sense. And, I like the idea so much I want to do the same.

Simplest way: on/off switch, and downstream of that, and in close proximity to your left hand or steering wheel, a normally on, momentary off button or rocker.

I don't think you want to do a keyed switch, the other clever solution suggested, because you'd be turning a key to get the same effect.

[JackE]

Originally Posted by Rucker

Ah, now it makes sense. And, I like the idea so much I want to do the same.

Simplest way: on/off switch, and downstream of that, and in close proximity to your left hand or steering wheel, a normally on, momentary off button or rocker.

I don't think you want to do a keyed switch, the other clever solution suggested, because you'd be turning a key to get the same effect.

I'm glad I'm not off my 'rocker' and someone else gets the idea. A normally on-momentary off push button is just as hard to find as the 3 position switch. I think I'll just have to wire it in with a relay, mostly because I want the push button to be lighted so it's easy to find in the dark. I'm also going to wire the trailer tail lights into this circuit so they flash with the clearance lights as well.

Definitely not a keyed switch, that eliminates the simplicity of this function.

[Doktari]

Have you tried McMaster Carr?. Do they do many switches?

[Rucker]

Originally Posted by JackE

I'm glad I'm not off my 'rocker' and someone else gets the idea. A normally on-momentary off push button is just as hard to find as the 3 position switch. I think I'll just have to wire it in with a relay, mostly because I want the push button to be lighted so it's easy to find in the dark. I'm also going to wire the trailer tail lights into this circuit so they flash with the clearance lights as well.

Definitely not a keyed switch, that eliminates the simplicity of this function.

Please share a circuit diagram when you get the time. Be sure to title it 'Unicorn Solution' or such.

[family wagon]

Originally Posted by JackE

Option 2: A 3 position toggle switch. Down position is off, middle position is on, up position is off but spring loaded to return to the middle position, allowing me to easily flash the lights without forgetting to flip them back on.

Pretty sure that's what the part I pointed to earlier would do. DigiKey says it is a DPDT switch (the data sheet isn't great, but it does have an email address where you can send application support questions). You only need one pole so the other goes unused. Hook up power to the common and the clearance lights to the On throw. When the switch is set in the On position power flows to the clearance lights. When it is pushed to the momentary/(On) position, power to the lights is cut and power is connected to the other throw (ie nothing). The spring returns to the On position and the clearance lights come back on.

Originally Posted by JackE

Option 1: On-off rocker switch. On position turns on clearance lights and a lighted push button on the switch panel right next to the rocker. When I push the lighted button, the clearance lights go out as long as the button is held in. Release the button, they come back on. Pushing the button in and out allows me to flash the clearance lights without having to flip the rocker switch on and off.

Try the NKK LP0125CCKW015CB. It is a DPDT momentary switch: at rest each pole connects to one of the throws (NC/normally closed); while the button is held down each pole connects to the other throw (NO/normally open). As with the toggle above the extra pole and the extra throw aren't necessary for your application. Just wire it up so the common gets the power and one of the NC throw terminals goes to the clearance lights.

This switch provides separate terminals for its built-in LED. Connect those to power and ground, and don't forget to add a current limit resistor -- this switch doesn't have that built in.


If you don't have to have the illumination in that pushbutton a simple SPST NC momentary switch would do the job (or an SPDT momentary, or a DPST NC momentary, or a DPDT momentary...). There must be boatloads of options when the illumination requirement is removed.

[JackE]

Originally Posted by family wagon

Pretty sure that's what the part I pointed to earlier would do. DigiKey says it is a DPDT switch (the data sheet isn't great, but it does have an email address where you can send application support questions). You only need one pole so the other goes unused. Hook up power to the common and the clearance lights to the On throw. When the switch is set in the On position power flows to the clearance lights. When it is pushed to the momentary/(On) position, power to the lights is cut and power is connected to the other throw (ie nothing). The spring returns to the On position and the clearance lights come back on.


Try the NKK LP0125CCKW015CB. It is a DPDT momentary switch: at rest each pole connects to one of the throws (NC/normally closed); while the button is held down each pole connects to the other throw (NO/normally open). As with the toggle above the extra pole and the extra throw aren't necessary for your application. Just wire it up so the common gets the power and one of the NC throw terminals goes to the clearance lights.

This switch provides separate terminals for its built-in LED. Connect those to power and ground, and don't forget to add a current limit resistor -- this switch doesn't have that built in.


If you don't have to have the illumination in that pushbutton a simple SPST NC momentary switch would do the job (or an SPDT momentary, or a DPST NC momentary, or a DPDT momentary...). There must be boatloads of options when the illumination requirement is removed.

Thanks for clearing my over-thinking up. I think I'm starting to see the light..... literally!

[mmoore6856]

such a switch was used in older trucks for flashing lites on-off-momentary on. should still be available look for clearance/ marker lite switch for trucks in the 70's

[Mudhutwarrior]

Cole-hersee should have something close. What your asking for is usually made for manufacturers of equipment to order as they are not common in the configuration your looking for. You might find one for restaurant equipment as I remember some old stuff used something similar. You can try Parts town as they cover most major brands in the industry. Myself I would not want something so uncommon and hard to find for services sake. General rule in a rocker or toggle is on off mom.

[rtdillon1960]

https://rockerswitchpros.com/switch-bodies/

IF anyone can help, these folks can...and they can make custom labels.

[Mudhutwarrior]

Originally Posted by rtdillon1960

https://rockerswitchpros.com/switch-bodies/

IF anyone can help, these folks can...and they can make custom labels.

There switches are based on the carling switch. They do nothing for configuration so your still stuck with on off mom.

[Polarweasel]

Is this what you’re looking for? It’s an OFF-ON-MOM switch body.

Found in the DPDT Special Circuit category btw...

[Rucker]

Originally Posted by Rucker

Ah, now it makes sense. And, I like the idea so much I want to do the same.

Simplest way: on/off switch, and downstream of that, and in close proximity to your left hand or steering wheel, a normally on, momentary off button or rocker.

I went and bought new LED clearance lights for the bus because the existing ones were old and probably leaky. The new kit came with a rocker switch, so I'll just install that in line to be able to toggle them.

Thanks for the suggestion!