Looking for 3PDT ON-ON-ON Toggle for UniVibe tremolo mod

[Kevin Mitchell]

I need to do a temolo mod to a couple univibe pedals this week. For this I'll need a 2P3T switch. The easiest thing to do would be to use a rotary switch. But that's not what Kevin wants!

Does anyone know where 3PDT ON-ON-ON toggle switches are available? I think BLMS had them a while back but not any more.
Here's my wire diagram - assuming I correctly recall how these switches work;


Here's info on the mod if anyone's curious.

Thanks for any help.
-KM

[Mark Hammer]

I realize it's "what Kevin wants".  But consider that the EHX Worm and Wiggler both use rotary switches to select their various capabilities.  If the esteemed Mr. Matthews can't get a toggle to do it, I doubt you're going to find it either.

Having said that, there are 3-position slide switches that can do MANY tricks.  Consider one of those.

[Kevin Mitchell]

If the esteemed Mr. Matthews can't get a toggle to do it, I doubt you're going to find it either.

I'm not asking for the impossible. As I've said, I'm pretty sure these 3 position switches were once available. Not so much anymore. I'll likely have to submit and use a rotary. The slide switch isn't a bad idea. However I'm not sure if I'm up to the task to file the slots. Always a PITA.

Thanks, Mark.
-KM

[davent]

Mouser has 4PDT's on-on-on for a small fortune.
https://www.mouser.ca/Electromechanical/Switches/Toggle-Switches/_/N-5g2j?P=1z0z2qmZ1z0z2o3

Digikey does as well, more expensive.

Never mind those, BLMS has a reasonably priced 4PDT.
https://lovemyswitches.com/taiway-4pdt-on-on-on-switch-solder-lug-short-shaft/
dave

[Kevin Mitchell]

Thanks, Dave!

I had forgotten that BLMS does have 4PDT (ON-ON-ON) switches. I suppose that would do just as well 
https://lovemyswitches.com/taiway-4pdt-on-on-on-switch-solder-lug-short-shaft/

Was unsure how the throws work since there's no diagram. Well there's the datasheet but it's a mess I suppose there's no harm in snagging a couple to try.

-KM

[mth5044]

The BLMS switch tells you exactly how the throws work in the bottom left table on the data sheet picture. It is as your picture shows of the 3pdt, but with the extra row also flipping down in position 2.

[Mark Hammer]

I will suggest that you leave a sufficient amount of time, or degree of sinking, to cool the unit down, between soldering connections to each lug.  At those prices, you don't want any heat buildup that could compromise the stability of the lugs in the plastic housing.

[Kevin Mitchell]

I will suggest that you leave a sufficient amount of time, or degree of sinking, to cool the unit down, between soldering connections to each lug.  At those prices, you don't want any heat buildup that could compromise the stability of the lugs in the plastic housing.

It only took ruining one stomp switch to learn that lesson 

And thanks, mth5044. I overlooked that part. Twas a late night.

Thanks.
-KM

[PRR]

> datasheet but it's a mess

Agree. Here's my WRONG! reading:

{edit: somehow the full image does not show on the PostImg page, but the Download there works fine...}
* See posts below for correction.

[RickL]

I think you've got the second diagram wrong. My reading of the switch positions is 2-3, 5-6 (not 5-4), 8-9, 11-10. That would make sense since this switch is just two of the dp on-on-on switches in a single housing. The dp on-on-on switches (Small Bear sells them) can be configured as a sp3t switch with a single jumper so it makes sense that these switches can be configured as dp3t with two jumpers.

[mth5044]

> datasheet but it's a mess

Agree. Here's my reading:

{edit: somehow the full image does not show on the PostImg page, but the Download there works fine...}

I think you're missing the 5/4 connection in the middle position!

[Kevin Mitchell]

Ohhh you guys 
.

-KM

[R.G.]

At the risk of complicating this further (    ) the CD4053 works fine as an AC or DC switch. As long as you're under its max of 18V (I think this part of the vibe runs on 17-18Vdc) you could use it to do the switching and use any three position two pole switch to run the 4053. Might be cheaper.

This is just at first glance. I'm still working on first coffee.

[Kevin Mitchell]

At the risk of complicating this further (    ) the CD4053 works fine as an AC or DC switch. As long as you're under its max of 18V (I think this part of the vibe runs on 17-18Vdc) you could use it to do the switching and use any three position two pole switch to run the 4053. Might be cheaper.

This is just at first glance. I'm still working on first coffee.

Thanks, R.G. When the toggle seemed illusive your 4053 switching was my first go-to. Your site was down that night. My initial thought was to use a DPDT ON-ON-ON switch and a CD4053. This would be ideal but I'll avoid switching circuitry wherever I can 

Although it would open the door for the use of an RGB status LED or even a tactile button instead of a switch   
Maybe my next build will have all of those bells and whistles.


-KM

[R.G.]

It's OK. Besides, I realized that the cd4053 is a three pole two throw switch, not a 3T. I did mention that it was my first cup of coffee.   

You could actally do it with two CD4052's, to get the third (or fourth) pole and up to four throws. But you would need some front end logic, yada, yada...

And from my own early difficulties, logic design is not something to do unless you really do need it. 

[anotherjim]

I would have expected on-on-on to have both changeover contacts of each pole switched "on" to the centre common lug in mid position 2, not the alternating mix shown in the diagram.

[Kevin Mitchell]

It's OK. Besides, I realized that the cd4053 is a three pole two throw switch, not a 3T. I did mention that it was my first cup of coffee. 

Actually for this mod only one of the two poles need three throws - the other is only two. 3 SPDT switches is exactly what would work and the CD4053 seem right for the job.

-One pole has two throws
-One of the throws of the 2nd pole would tie into the 3rd pole
-Effectively giving us the equivalent of 1P2T & 1P3T

So long as the 3rd pole is triggered independently which is where the DPDT ON-ON-ON switch or alternatively a controlled voltage switching/trigger circuit would come into play.

I understand visualizing this can be a headache 

-KM