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I'm looking for a toggle or slide switch that has an off and two on positions and is spring loaded to automatically return to off, but one of the on positions is past the other one.

So instead of "on-off-on", I want one that is "off-on-on"

Or maybe "off-onA-onB"

And it should be momentary, so maybe that would be "off-(on)-(on)"?

So you push it to the first click to turn on the "onA" circuit, and then can push it further to turn on "onB".

For my application it would be fine if the second load is only an additional "on" (in other words, onA is also still on when we switch to onB), much like a car key ignition.

But if pressure on the switches is released, the switch automatically returns all the way to off.

Anyone know where I can find a switch like this?

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    \$\begingroup\$ Googling for "off-on-on" returned this as the first hit: 12voltplanet.co.uk/off-on-onon-toggle-switch-25a12v.html \$\endgroup\$ – pjc50 Apr 25 at 10:09
  • \$\begingroup\$ @pjc50 Good find! OP wants a dual pole and return to OFF but those are just variations on what you have found. With that contact arrangement is should be possible to do what OP wants with the use of relays if nothing else is available. The return to OFF is still not confirmed. \$\endgroup\$ – KalleMP Apr 25 at 21:03
  • \$\begingroup\$ I suppose with a rubber band the off-on-on would work, but I want it to be momentary \$\endgroup\$ – David Ljung Madison Apr 26 at 23:12
  • \$\begingroup\$ I'm starting to wonder if I just need to use two switches with different spacing or springs but using the same physical button switch. \$\endgroup\$ – David Ljung Madison Apr 26 at 23:19
  • \$\begingroup\$ Your question omits information about the signal to be switched and size constraints. You might be able to find this in a large industrial switch but that might not suit your purposes. If you are switching low voltage then you may need gold contacts. "I suppose with a rubber band the off-on-on would work, but I want it to be momentary." Push buttons usually stay on for as long as they are pressed. Do you require something else? Can you add a timing diagram? What happens if the button is pressed half-way and released? What is the application? \$\endgroup\$ – Transistor Apr 27 at 7:35
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Sort of, this kind of switch is commonly used as a shutter release for digital cameras. They are not the old style toggle type but they work more like tactile momentary type and rely on two different pressure levels to operate. A half press is used to activate the auto-focus and then fully pressing it will take the photo.

Questions about where to buy stuff are off topic but hopefully this gives you a starting point.

If you definitely require an old school up-middle-down lever style toggle then you can get units that are user configurable, where you need to open it up and move the contacts and springs to suit your needs. These are expensive of course.

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The type of switch you are looking for is called a "momentary" switch. They are available in different forms including a 'toggle' (or bat handled) switch, slide switches and even rotary switches (less common). They are available in different sizes too.

You may find that a DPDT (double pole, double throw) momentary (spring loaded) off-on-off may be able to serve your purpose. You can use its two switches-in-one to provide you with an off-on-on type of result.

If you look at the schematic equivalent of a DPDT switch, you will quickly see how to use it in this way...

At least one place to purchase a switch of this type is at Alibaba.com, search for "DPDT momentary toggle switch". They are also available on Amazon.com and most electronic supply houses.

However you can use a standard DPDT (ON) OFF (ON) momentary switch to get what you want, or close to it anyway. This will work IF you can live with the center position as OFF and then use the (left and right) positions as onA and both onA and onB. A DPDT switch is two SPDT switches in the same package. So lets call them switches A and B. If you wire A to provide you with your 'onA' in both the left and right positions, then if you press the switch left or right onA is turned ON, but in the center position it is OFF. Now wire the 'onB' on the B part of the switch in the (right) position only. In doing so, you will have the spring loaded center position of OFF, then the left momentary position of onA and the right momentary position of both onA and onB. :)

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  • \$\begingroup\$ I just learned about what (ON) means as opposed to "ON" and that helps me describe it, so I'll edit my question. But what I need is something that is momentary and returns to the first position, not the middle position. \$\endgroup\$ – David Ljung Madison Apr 26 at 23:11
  • \$\begingroup\$ Depending on how you use the contacts of the switch the 'middle' can provide what you want. \$\endgroup\$ – Wendall May 1 at 15:00
  • \$\begingroup\$ There are also momentary switches that are normally closed (or ON) as well as normally open (Off). \$\endgroup\$ – Wendall May 1 at 15:01
  • \$\begingroup\$ And can you give me an example of such a switch that could be used the way I wanted without adding extra circuitry (such as an inverter or relay?) \$\endgroup\$ – David Ljung Madison May 1 at 17:40
  • \$\begingroup\$ At one time (30 years ago) there were switches that could be "ganged" together to create exactly what you want, I do not find them now.However I will leave another answer with how to wire up a momentary DPDT to achieve 'about' what you want. \$\endgroup\$ – Wendall May 1 at 19:59

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