Mysteries of the on-on-on DPDT

[nickbungus]

Hi All - Simple and probably dumb question today!

Is it possible to use a DPDT on-on-on switch (either version) to switch between say three different caps (or resistors or leds etc)

I'm trying to figure out of the purpose of them and when to use them.

[EBK]

Yes, an on-on-on can be wired as a sp3t switch. 
Here is a quick search result:

[italianguy63]

Yes, an on-on-on can be wired as a sp3t switch. 
Here is a quick search result:

Cool.. but, I'm not seeing it!  Can somebody show a diagram of the switch in each of the 3 positions so it is more clear how it works?

MC

[EBK]

The vertical lines are the internal connections for each position.

The diagonal line represents a wire soldered to the switch terminals.

[italianguy63]

The vertical lines are the internal connections for each position.

Thank you!
MC

[italianguy63]

So the white parts of the upper diagram are PCB traces?

MC

[EBK]

So the white parts of the upper diagram are PCB traces?

No.  They are the internal switch connections when the switch is in the center position.  There are two variations of these switches, which are mirror images of each other. (I've illustrated what that diagram calls Type "A".)

[GGBB]

I just posted this in another thread. This is a pickup selector, but it could be an anything selector:

The DPDT on-on-on toggles we are used to using are more truly SP3T switches than DPDT, and a short time ago when I was trying to find some (on DigiKey or Mouser or ?), they were only listed under SP3T. Mysterious indeed!

[italianguy63]

So the white parts of the upper diagram are PCB traces?

No.  They are the internal switch connections when the switch is in the center position.  There are two variations of these switches, which are mirror images of each other. (I've illustrated what that diagram calls Type "A".)

OH!!!  Thanks again!

[italianguy63]

Trying to implement this to a PCB (mounted) could be hard AF!  i.e... Type A or Type B vs. traces on PCB.  It could be REALLY easy to get it backwards in design!!

Found this one:

https://lovemyswitches.com/taiway-sub-mini-dpdt-on-on-on-switch-pcb-mount-long-shaft/

This could be really useful for different "clipping" selections.. I'd like to try it eventually.

[GGBB]

There are two variations of these switches, which are mirror images of each other. (I've illustrated what that diagram calls Type "A".)

For the record, I've only ever run into the one type. But it's not like I've looked at everything out there. Still - it always pays to be certain.

[digi2t]

Trying to implement this to a PCB (mounted) could be hard AF!  i.e... Type A or Type B vs. traces on PCB.  It could be REALLY easy to get it backwards in design!!

Found this one:

https://lovemyswitches.com/taiway-sub-mini-dpdt-on-on-on-switch-pcb-mount-long-shaft/

This could be really useful for different "clipping" selections.. I'd like to try it eventually.

We've used these on two different DEFX projects to date, the Leo X (Schumann Lion X) and the Pompei (Synthi Hi Fli). There are two angles here. In the case of the Pompei, we decided to stay with the one type of switch. Of course, availability of one or the other might always be an issue, or as you pointed out, it could be easy to mix up the configuration when doing a PCB layout. In that case, if space allows, you could always design in the option to use either. On the Leo X we included jumper pads to allow for configuring the board to accept either type I or type II switches.

[GGBB]

We've used these on two different DEFX projects to date, the Leo X (Schumann Lion X) and the Pompei (Synthi Hi Fli). There are two angles here. In the case of the Pompei, we decided to stay with the one type of switch. Of course, availability of one or the other might always be an issue, or as you pointed out, it could be easy to mix up the configuration when doing a PCB layout. In that case, if space allows, you could always design in the option to use either. On the Leo X we included jumper pads to allow for configuring the board to accept either type I or type II switches.

How do you manage the smaller depth of those along with PCB mount pots? Or do you not use PCB mount pots?

[mimmotronics]

On the Leo X we included jumper pads to allow for configuring the board to accept either type I or type II switches.

Great design choice! I'll have to think about that for future projects.

[nickbungus]

Thanks guys.  That's just what a needed.  Was really trying to work it out and scratching my head

[digi2t]

We've used these on two different DEFX projects to date, the Leo X (Schumann Lion X) and the Pompei (Synthi Hi Fli). There are two angles here. In the case of the Pompei, we decided to stay with the one type of switch. Of course, availability of one or the other might always be an issue, or as you pointed out, it could be easy to mix up the configuration when doing a PCB layout. In that case, if space allows, you could always design in the option to use either. On the Leo X we included jumper pads to allow for configuring the board to accept either type I or type II switches.

How do you manage the smaller depth of those along with PCB mount pots? Or do you not use PCB mount pots?

We always design around 16mm pots, but I always build using 16mm pots with PCB pins (i.e. what Tayda sells), and then use 20 AWG solid core copper for the legs. This allows for easy jigging to match the toggle deck height, as illustrated below;



Once all the pot legs are prepped, I have a special piece of pre-cut foam that I insert under each pot to jig the pot to the right height. I solder the center pin first, double check the height and alignment, and then solder the two outside pins.

This method allows for easy adaptation of the pots to any toggle, or rotary switch (or both) height. We also find that using the 16mm pots with the PCB pins allows for the best selection to cost ratio.

If additional rigidity is required, you can also design in some standoffs and screws as well.

On the Leo X we included jumper pads to allow for configuring the board to accept either type I or type II switches.

Great design choice! I'll have to think about that for future projects.

Sorry, I made a mistake on the project using the the jumper pads. It's actually the Harvey Dent (Schumann Two Face Fuzz). If you look at the build doc, the jumper configuration, along with schematic, will show you how we arranged the jumper pads.

https://drive.google.com/file/d/11aNJE4s0HkYvhK__tqktWkmPaP_UoiO1/view

[GGBB]

Once all the pot legs are prepped, I have a special piece of pre-cut foam that I insert under each pot to jig the pot to the right height. I solder the center pin first, double check the height and alignment, and then solder the two outside pins.

This method allows for easy adaptation of the pots to any toggle, or rotary switch (or both) height. We also find that using the 16mm pots with the PCB pins allows for the best selection to cost ratio.

But - I'm confused - aren't the pots deeper body-wise than the toggles? Especially those sub-minis? If anything I would have expected that you'd need to prop up the toggles and put the pots down as far as possible. What I've had to do in the past is use top and bottom nuts on the toggle bushing to get it to mount flush with the pots. I was wondering if the sub-mini toggles would be too short to be adjustable that way.

[John Lyons]

Not exactly what you are asking but i use this
to get 3 different cap values.
The smallest cap goes in the
middle position.
Off is middle/small cap only.

[digi2t]

Once all the pot legs are prepped, I have a special piece of pre-cut foam that I insert under each pot to jig the pot to the right height. I solder the center pin first, double check the height and alignment, and then solder the two outside pins.

This method allows for easy adaptation of the pots to any toggle, or rotary switch (or both) height. We also find that using the 16mm pots with the PCB pins allows for the best selection to cost ratio.

But - I'm confused - aren't the pots deeper body-wise than the toggles? Especially those sub-minis? If anything I would have expected that you'd need to prop up the toggles and put the pots down as far as possible. What I've had to do in the past is use top and bottom nuts on the toggle bushing to get it to mount flush with the pots. I was wondering if the sub-mini toggles would be too short to be adjustable that way.

Perhaps sub-minis, but not minis which are pictured in my post. That's why you clearly see the pots sitting off the board in the first picture. Here some dimensions, though the plastic cap that comes on the Tayda pots is not included into the dimensions, so add another 2mm there. Keep in mind, there are extrusions on the lug side of the toggle that make so the switch sits a tad higher than the actual dimension. Also, you don't want to be installing a toggle with out a nut on the backside of the enclosure. Cinching the nut on the outside, without the nut on the inside, can actually rip the bushing right off the switch. As such, this raises the deck height of the switch to above the 16mm pot's deck height.

[garcho]

Cinching the nut on the outside, without the nut on the inside, can actually rip the bushing right off the switch.

i've made that mistake before, once with a pot, too. never again!