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joystick question

2007-10-22 by rafe127

Hi all,
I am working on the joystick circuit from here:
http://www.cgs.synth.net/modules/joystick.html
and I have a few questions about it... it doesn't seem to be behaving
as expected.

I am using a TL074 as the op amp.

The range control at minimum causes the joystick's travel to change
the voltage output very little as expected. However, when I try to
add offset to the output in this state, it adds almost nothing...
like 0.2 volts or something. Offset seems to work OK when the range
is high. I was hoping that I could set it up so that the travel of
the joystick could make the output range from 0V-5V if I wanted or
from 4.5V - 5V if I wanted. Is this a possibility with the circuit
as it is designed?

Also, I am having trouble setting the values (with the range pot at
maximum). I have tried it with the bottom of the joystick hooked to
the neg. rail as suggested, and also with it hooked to ground but it
is not ever giving me a range of 0-5V no matter how I set the values.

Any help appreciated.

Rafael

Re: joystick question

2007-10-23 by sasami@hotkey.net.au

Range will affect the offset with the circuit as shown.
If you want the offset to be totally independent of range, reverse the power
connections to the offset pot, and connect the wiper via a 47k to pin 6 of
the op-amp instead of pin 2. Pin numbers given as per my diagram: you'll
need to substitute your own pin numbers. If the resultant offset range is
too large, put a trimpot in series with the 47k resistor.

Ken

Show quoted textHide quoted text

>Hi all,
>I am working on the joystick circuit from here:
>http://www.cgs.synth.net/modules/joystick.html
>and I have a few questions about it... it doesn't seem to be behaving
>as expected.
>
>I am using a TL074 as the op amp.
>
>The range control at minimum causes the joystick's travel to change
>the voltage output very little as expected. However, when I try to
>add offset to the output in this state, it adds almost nothing...
>like 0.2 volts or something. Offset seems to work OK when the range
>is high. I was hoping that I could set it up so that the travel of
>the joystick could make the output range from 0V-5V if I wanted or
>from 4.5V - 5V if I wanted. Is this a possibility with the circuit
>as it is designed?
>
>Also, I am having trouble setting the values (with the range pot at
>maximum). I have tried it with the bottom of the joystick hooked to
>the neg. rail as suggested, and also with it hooked to ground but it
>is not ever giving me a range of 0-5V no matter how I set the values.
>
>Any help appreciated.
>
>Rafael
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

CGS modules at +/-12V, board size questions

2007-10-23 by Anthony Rolando

Ken, are there any of your designs that just will not operate at +/-12V?

I am looking to order some more of your boards to put into a Doepfer suitcase for touring.

These look to be operable at 12V with some R changes, am I correct?
CGS64 VCA
CGS26 Analog Logic voltage processor

Roghly what size are these?
Gated Comparator (what size is this one?)
CGS36 Pulse Divider and Boolean Logic

Thanx for your time,

Tony
_________________________________________________________________
Peek-a-boo FREE Tricks & Treats for You!
http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us

Re: CGS modules at +/-12V, board size questions

2007-10-23 by sasami@hotkey.net.au

>Ken, are there any of your designs that just will not operate at +/-12V?

I can't think of any that won't run on +/-12V.

>These look to be operable at 12V with some R changes, am I correct?
>CGS64 VCA
>CGS26 Analog Logic voltage processor

They may not even need any changes at all, unless i metnion it in the notes
at the bottom of the pages.

>Roghly what size are these?

2" x 6" is the usual size. Sizes are also usually give n at the bottom of
the pages.

>Gated Comparator (what size is this one?) 2 x 4.6 apprx
>CGS36 Pulse Divider and Boolean Logic 2 x 6

Ken
_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>

Cgs synth

joystick question

joystick question

Re: joystick question

CGS modules at +/-12V, board size questions

Re: CGS modules at +/-12V, board size questions

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