rotary switch headache...

[deadastronaut]

hi guys,   i need some help with this rotary switch lark....

i have a 3 pole 4 way rotary switch...(which i presume i'm going to need as one setting switches 3 things at once..)

however my experience  with rotary switches is practically non existant...

looking at the schematic below this is my list of switching requirements (switching on the gain stages)..  (the input caps 22n/100n will be seperate)

1  Q2  10K         Q3  10K........fuzz

2  Q2  680K       Q3  10K.......oct

3  Q2 680K        Q3  220K....swell

4  Q2 680K        Q3  one leg of diode lifts, whilst adding a resistor to ground.  ( theres the trickiest part.).........synth swell.



any help appreciated on how to wire this up as its doing my head trying to suss it out ....    (ignore the 820k to ground ok)

[ch1naski]

So far I see that Q3 is going to need to two poles to itself....

[Digital Larry]

You'll need to group the things together into "connections I want to have at the same time as long as there aren't more than three of them".  As it stands you have at least 4 switches being used and it's not clear to me which combinations of them are useful.  Since grouping switches together involves trading flexibility for ease of use, you'll have to make some of these tradeoffs up front.

[Govmnt_Lacky]

BTW.. just for clarification.

Where is Q3 in that schematic? I see Q1, Q2, Q4, and Q5.

Typo?? 

[deadastronaut]

Q5=Q3...

ignore the 820k....and the cap switch..

its just around the gain stages that are relevant for switching...


@larry:  yes i get you on the grouping ...hmmmm...

[ch1naski]

So if A=q2, B=q3, then lug 1and 5 should both go to their respective 10k resistors  - lug 2 =680/lug 6 = tied to lug 5....lug 3 tied to lug 2/lug 7=220k ..    Which only leaves one lug left for poles a and b, but pole c  and it's 4 lugs are so far unused....

Thinking out loud...

[deadastronaut]

schemo updated...

[armdnrdy]

1  Q2  10K         Q3  10K........fuzz

2  Q2  680K       Q3  10K.......oct

3  Q2 680K        Q3  220K....swell

4  Q2 680K        Q3  one leg of diode lifts, whilst adding a resistor to ground.  ( theres the trickiest part.).........synth swell.



any help appreciated on how to wire this up as its doing my head trying to suss it out ....    (ignore the 820k to ground ok)

I can't figure out what you are trying to accomplish. Maybe not enough coffee or.....not enough information.
How about adding component designations for the resistors in the above switching chart.

[deadastronaut]

ha ha nor can i.... .........arghhhhhhhhh my head.

basically the 680k is in line...with a 10k switch, 10k on/off.  Q2

then a 220k in line with a 10k switch, 10k on/off  Q3

diode lift switch...which will also take a resistor to ground.....

to achieve the 4 options listed  (in bold)


1  Q2  10K    +     Q3  10K........fuzz

2  Q2  680K   +    Q3  10K.......oct

3  Q2 680K    +    Q3  220K....swell

4  Q2 680K    +    Q3  one leg of diode lifts, whilst adding a resistor to ground.  ( theres the trickiest part.).........synth swell.

[armdnrdy]

Okay,
I think I understand what you want as far as switching options....but when you switch from position 1 to position 2, in what state do you want option #1 to be in? The state before it was switched or after? The 680K or 10K?

You can achieve many more options with a rotary switch and cmos IC's such as 4053's or 4066's.

[digi2t]

So, if I understand correctly, you wish that each position on the rotary closes the switch for the circuit you`ve listed, whist the others are open?

If so, maybe that`s how you should approach it. Since you  have 3 common, or com, poles (A, B, C), each pole has four possible connections. «A» covers 1, 2, 3, and 4. «B» covers 5, 6, 7, and 8, and «C» the remaining ones.

With that said, three of the contacts are closed in any one position. When the switch is in the first position, A1, B5, and C9 contacts will be closed while the others will be open. Switching to the scecond position, A2, B6, and C10 will be closed, and so on.

Looking at the schematic, the fixed end of the switch symbol represents the com. Looking at the «Fuzzy/Synthy» switch, this will be the upper point of the three. This point will connect to a com (A, B, or C) on your rotary. If you choose «A», then the two other wires will connect to either 1, 2, 3, or 4, depending on where in the rotation you wish the connect/disconnect to happen. This means that you`ll have to take the other switching schemes into consideration, i.e. will certain switches open/close simultaneously, or will they be staggered.

I hope this helps.

Dino

[slacker]

Yeah Dino's got it.  A, B and C correspond to the poles of your individual switches on your schematic, then for your first setting look at throws 1, 5 and 9 and connect them to give you what you want for that setting. For example 1 to R23, 5 to R22 and 9 to D5. Then look at throws 2, 6 and 10 and connect those how you want for that setting.

[deadastronaut]

cheers guys,  what i don't get is that i'm going to need 9v going to com A  to feed the collectors though , which in turn will mess with d5 too...

unless i'm looking at things the wrong way...which is very likely hmmmm....anyone got a diagram for a dumbass

[slacker]

I think you're looking at it wrong Rob. A 1,2,3,4 is your Q2 switch B 5,6,7,8 is your Q3 switch and C 9,10,11,12 is your fuzz/synth switch. These are 3 totally independent switches

So for Q2 A to +9, 1 to the top of R23, 2,3 and 4 unconnected. In position 1 this connects R23, in the other positions R23 is not connected.
For Q3 B to +9, 5 and 6 to the top of R22. This connects R22 in positions 1 and 2 and leaves it unconnected in positions 3 and 4. That's assuming you don't want it connected in position 4, if you do connect 4 to 1 and 2.
For the fuzz/synth Connect C to the diode D6, connect 9, 10 and 11 to diode D5, connect 12 to R24. This connects the diodes in positions 1, 2 and 3 and lifts the diode and connects the resistor in position 4.

Hope that makes sense.

[deadastronaut]

lol, i thought i was...no surprise there eh. ..cheers ian, your a star.

i''ll knock up a drawing of what you've written in a bit to make sure ive grasped it properly.....bit by bit.

cheers guys

[deadastronaut]

ok, according to Mrs astronaut (my assistant  )  she says it  should look like this..





is this correct, or will i have to launch her into deep space again...?

[slacker]

As we know is always the case Mrs Astro is spot on.

[deadastronaut]

brilliant, i'll cancel the launch sequence then...

cheers man, thanks a bunch...

now to knock up the pcb...

[deadastronaut]

ok, just to confirm i have this right....with the bonus of freehand art too..

[duck_arse]

I said I was gunna, and I did. I don't know if it's 100%, but I think it's neat enuff to make corrections easy/obvious.