Re: [sdiy] 3PDT

[Roman]

here's my idea:
SPDT with center off. Outer contacts via resistors to GND, center to VCC. Outer ones drive address lines of 4051 or similar mux.
Or add OR gate made with 2 diodes and resistor, 2x N-FET, 1x P-FET and go without a MUX, but that may be not usable in some circuits.
Is the circuit clear or should I draw a schemo?

Roman

---- Wiadomość Oryginalna ----
Od: mark s <djarum11 at mindspring.com>
Do: synth-diy at dropmix.xs4all.nl
Data: Mon, 24 May 2004 22:07:36 -0400
Temat: Re: [sdiy] 3PDT

>thanks larry, i think i'm going to have to go with a rotary switch because 
>the SP3T's are too pricey for me ($13? no thanks)
>
>cheers
>mark
>
>At 10:01 PM 5/24/2004, you wrote:
>>SP3T switches are indeed available.  They feel like a SPDT with center off,
>>but the center off position is not off. These switches actually have 2
>>poles.  They switch like this:
>>pole 1 (center to top/bottom)
>>ON / OFF
>>ON / OFF
>>OFF /ON
>>
>>pole 2
>>ON / OFF
>>OFF / ON
>>OFF / ON
>>
>>They "look" like DPDT switches from the back, but they are not.  You have to
>>connect a jumper from the one pole to the other to get 1P3T operation.
>>
>>See small attached graphic file.
>>
>>Larry Hendry
>>
>>
>>----- Original Message -----
>>From: mark s <djarum11 at mindspring.com>
>>To: <synth-diy at dropmix.xs4all.nl>
>>Sent: Monday, May 24, 2004 8:41 PM
>>Subject: Re: [sdiy] 3PDT
>>
>>
>>ah yes
>>
>>was thinking of three throws (SP3T etc) but there are only two.
>>
>>thanks
>>m
>>
>>At 09:07 PM 5/24/2004, you wrote:
>> >On Mon, May 24, 2004 at 09:01:28PM -0400, mark s wrote:
>> > > hi list
>> > >
>> > > would a 3PDT on/off/on allow me to select between 3 outputs, or just two
>> > > (with the middle position non-conducting) ?
>> >
>> >3PDT has 3 poles, but two positions.  You're thinking of 2PDT Center Off,
>>or
>> >2PTT or whatever its called properly with 3 seperate selection
>> >points.  Guitars
>> >commonly have these although I dont know if you'd find one applicable to
>>your
>> >application.
>> >
>> >--
>> >  ------------------------------------------------------------------------
>> >  - Tom Arnold -       When I was small, I was in love,                  -
>> >  - Sysabend   -       In love with everything.                          -
>> >  - CareTaker  -       And now there's only you...                       -
>> >  --------------         -- Thomas Dolby, "Cloudburst At Shingle Street" -
>>
>>
>
>