3PDT Footswitch PCB Question

[RRJackson]

I bought a pack of 10 of these off eBay and then realized I wasn't sure how to wire them up. I've asked for a wiring diagram, but haven't heard anything in reply. There are eight points for wiring connections. The other side of the board has labels that say, 'W1' and 'W3' by the outside two positions and then the middle six are grouped together in a box that says, 'W2.'

I realize this is probably kind of remedial, but I keep staring at the board and haven't really made a lot of sense of it. I mean, some of the traces look logical enough, but then others completely stump me.

As usual, any assistance would be greatly appreciated.

-Rob

[PRR]

More pictures:

http://pedal-parts.com/en/footswitches/3pdt-switch-with-pcb-detail

9 nubs on the switch to 8 wires... something is missing. Some switch schemes only use one side of a pole to do the LED, but others use all 9.

Maybe it is the photography, but I'm not keen on the soldering.

If there is any "remedial" here, it is that you don't let other people wire your switch.

If all thought fails, I'd run the blowtorch over the PCB, beat off the solder, and use the switch (maybe some of the wires). I don't see what the PCB really adds here, except confusion and limited options.

[RRJackson]

I actually bought mine from a Chinese seller. They're the same PCB, but without the wires. Here's the eBay auction photo. I just assumed they'd come with a wiring diagram of some kind or labeling on the PCB...or something. Very frustrating.

I can do some kind of messy wiring on those footswitch lugs sometimes. I thought this might make for neater work. Got myself a bucket of grief in the process. Heh...

[PRR]

If not even any wires, I'd ignore the PCB.

The 9 lugs are plain. And 9-lug is the usual way pedal switching is drawn.

Mount your soldering iron in a stand so you can poke wire at its tip.

Strip an appropriate stranded insulated wire just 1/8" (3mm).

Tin the iron, then lay the wire on the tip, hit it with solder so it melts, and get out. Should be 1 to 3 seconds max.

Repeat 8 times.

Now clamp the switch. (You can NOT solder jacks or switches rolling around the bench.) The lugs are already tinned. (If they weren't, you'd tin them.) Hold a tinned wire against the lug. Touch the iron to the wire *just* until the molten solder on the wire starts to melt the solder on the lug. Get out fast, but do not let the wire move until hard. (A 3rd-hand is valuable; nail a house-wire to the bench and crimp a gator-clip to the end.)

This butt-solder technique "violates" a basic guide for Good Soldering. You "should" have a good mechanical joint (hook in hole, wrap) before you solder. However a *good* butt-solder holds up pretty darn well. I think the problem is that when you solder for $3/hour you just solder good-enough to get paid; when you solder for YOURSELF you will be SURE by inspection and gentle yanks that EVERY joint is firm and strong.

[RRJackson]

I have plenty of footswitches without PCBs on 'em if I want to do it that way. I was just trying to actually use these.

[mth5044]

Your best bet is to take a pencil and paper, draw three schematic swirches then trace the PCB and draw it up. There might be a few ways to wire it. Give the pads labels 1-8, or A-H, then wire them up.

If you aren't familiar with switches, or bypass diagrams, post a nice picture of the bottom and paint-draw the missing traces and I'll help you out. You can figure out which pads go to what poles useing a multimeter with continuity or just resistance.

[RRJackson]

Your best bet is to take a pencil and paper, draw three schematic swirches then trace the PCB and draw it up. There might be a few ways to wire it. Give the pads labels 1-8, or A-H, then wire them up.

If you aren't familiar with switches, or bypass diagrams, post a nice picture of the bottom and paint-draw the missing traces and I'll help you out. You can figure out which pads go to what poles useing a multimeter with continuity or just resistance.

I'm an idiot. I don't know why I hadn't just tested continuity from the pads to the lugs.

So here's what I got. Positions 1 and 3 both feed the same two lugs. Positions 6 and 8 feed a different pair of lugs.

Well, at least I have some idea what's going on here now. Thank you for kicking some sense into my skull.

-Rob

[mth5044]

do the top row of lugs change when you push the switch, and what numbers do they change to?

[RRJackson]

do the top row of lugs change when you push the switch, and what numbers do they change to?

Wow. Completely didn't think of doing that, either. It's like someone from a nail salon decided to pick up a soldering iron. My apologies.

Here's what I get with the switch engaged...or disengaged, as the case may be.

[R.G.]

I know! Let's make a PCB to connect wires to the PCB that connects to the 3PDT switch!! 

Simple but brilliant!!

Seriously folks, I do not get why a pcb to connect wires to a 3PDT is any better than soldering wires to the switch - especially if you then have to figure out what wire does what on the switch. Sure, if the PCB connected all that mess up without having to figure out what wire was what, and removed the issue of confusing the terminals entirely, but ... really?? Why?

[RRJackson]

Eh, you certainly have a point. I'll tell you why the idea appealed to me. I tend to keep 22 AWG wire with a Teflon jacket around and it's both stiff and hard to strip on short little runs like that. So sometimes my 3PDT wiring looks like I tried to do it with Rebar. I know, I know...the answer is to buy different wire stock to use for pedals than what I normally keep around, but where's the self-induced trauma in that. ;-)

-Rob

I know! Let's make a PCB to connect wires to the PCB that connects to the 3PDT switch!! 

Simple but brilliant!!

Seriously folks, I do not get why a pcb to connect wires to a 3PDT is any better than soldering wires to the switch - especially if you then have to figure out what wire does what on the switch. Sure, if the PCB connected all that mess up without having to figure out what wire was what, and removed the issue of confusing the terminals entirely, but ... really?? Why?

[PRR]

> I do not get why a pcb to connect wires to a 3PDT is any better than soldering wires to the switch

(As I am sure you know) when you mass-produce it can make sense to do the main circuit and switch on one PCB with a tear-off for the switch section. You stuff and wire the one PCB. Then break-off the tear-off, tethered by jumpers, so the main and switch PCBs can be mounted to their different places.

Totally agree that a standalone switch PCB misses the work-savings of joint assembly.

Not to mention that it doesn't bring all 9 legs out, and doesn't seem to even get 8 legs out?

These must be left-overs from some larger production which went bad. (Perhaps because it was short-legged.)

Teflon is good stuff but you need the special strippers.

[karbomusic]

I think every small-time builder goes 'neat!', buys a few of those, uses one, then the rest go in a drawer to never be touched again. If that is not you, call me, I have a few to get rid of. Another note is you just went from 9 solder joints that might fail, to 18. 

[jez79]

Pinout:

N/C   6     3 (second pic should have 3 here, instead of N/C)

5      8     1

4     7      2

In one position, top row is connected to middle row (first pic)
In other position, bottom row is connected to middle row (second pic)

[RRJackson]

Teflon is good stuff but you need the special strippers.

I make do with whatever strippers wander over to my table! ;-)

I'm here all week! Try the veal and remember to tip your waitress...and your stripper!

-Rob

[RRJackson]

Pinout:

N/C   6     3 (second pic should have 3 here, instead of N/C)

5      8     1

4     7      2

In one position, top row is connected to middle row (first pic)
In other position, bottom row is connected to middle row (second pic)

Handy! Quite handy. I must not have made solid contact on the N/C. Thanks!

-Rob

[jez79]

I mean that there is no wire hole (1,2,3,4,5 6,7,8) for that 3PDT connection, no wire goes to it (the one above 4 and 5)
That column is used to switch LED on/off, and is used as a single pull switch, either connecting or not connecting the powered LED to GND.
Usually, send +9V --> Rled (usually 4.7k, but check and adjust) --> LED +
Then wire LED - to 4 on your switch
Send GND to 5 on your switch

The other pins/wires/#s on your switch are the dpdt circuit bypass

[jez79]

Here are some ways you could wire the bypass:
(1)
1 - INPUT
8 - OUTPUT
7 - connect to - 2
3 - CIRCUIT IN
6 - CIRCUIT OUT

(2)
2 and 6 - INPUT
1 - CIRCUIT IN
3 - GND
8 - OUTPUT
7 - CIRCUIT OUT

Version 2 has the advantage of grounding the circuit input, at the expense of a jumper.
I assume this prevents the circuit from doing weird stuff while you're not looking. Sneaky buggers....

[RRJackson]

Much appreciated. Thank you.

[Trancedental]

There's much better pictures on this website http://pedal-parts.com/en/footswitches/3pdt-switch-with-pcb-detail where you can check exactly where each wire connects to each lug on the switch.

Looks like a Ukrainian / Russian website? Maybe it's in Crimea? 

Anyway they should tell you exactly how to wire it up