electro-music.com   Dedicated to experimental electro-acoustic
and electronic music
 
    Front Page  |  Articles  |  Radio
 |  Media  |  Forum  |  Wiki  |  Links  |  Store
Forum with support of Syndicator RSS
 FAQFAQ   CalendarCalendar   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   LinksLinks
 RegisterRegister   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in  Chat RoomChat Room 
Live streaming at radio.electro-music.com

  host / artist show at your time
  Faux Pas Quartet and friends Music From Last Thursday
Please visit the chat
 Forum index » DIY Hardware and Software
Voltage Control of Sequencer Step Count?
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 2 of 2 [39 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Goto page: Previous 1, 2
Author Message
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Tue Sep 11, 2012 2:33 am    Post subject: Reply with quote  Mark this post and the followings unread

ah been looking into Dave's idea
using LM3914 to CD4532 and CD4051 he had the answer all along it seems
it would prevent a double output from ever occuring thanks Dave Smile
only thing missing is NOT gates on the LM3914 outputs to drive the CD4532 inputs and we can also have LED indicators running directly from the LM3914 as well
So for an 8 way CV addressable switch seemingly it can be done with
only 3 chips 8 x 2n3904 and a hand full of resistors and caps and 8 LED's
although for a stand alone module i would also add a sample and hold to the incoming CV before the LM3914 to provide a clocking/ timing ability
the YASH circuit comes to mind
it could also be done from the CD4532 enable in pin but i think the sample and hold would be preferable as it effectively prevents output changes during the clock pulse on time.
would make an excellent module by itself i think and well worth the effort to prototype, what do you think matthias ?

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
fonik



Joined: Jun 07, 2006
Posts: 3759
Location: Germany
Audio files: 23

PostPosted: Tue Sep 11, 2012 6:34 am    Post subject: Reply with quote  Mark this post and the followings unread

yep. dave, you have become a CMOS guru, my friend!
_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
fonik



Joined: Jun 07, 2006
Posts: 3759
Location: Germany
Audio files: 23

PostPosted: Tue Sep 11, 2012 6:36 am    Post subject: Reply with quote  Mark this post and the followings unread

@diablojoy: would make a nice module indeed.
_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Tue Sep 11, 2012 4:03 pm    Post subject: Reply with quote  Mark this post and the followings unread

hmm one slightly annoying limitation
the CD4051 will switch bipolar signals but is limited to around +/-7.5 volts
in that case the chip must be supplied +/- 7.5 volts on the VDD and VEE pins respectively but in that case it will not be able to switch a +10v
signal such as a gate or reset . If VDD is supplied with +15v and VEE is at ground then gate , reset or clock signals could be switched, which is fine for the original topic but you can then no longer switch bipolar signals
If to be used for a CV addressable switch module this is quite limiting indeed
To get around this so far my only thought is to use the CD4051 I/O's to switch a pair of DG412 chips instead of doing the signal switching directly.
but it does add some more complication to the circuit
Anyone have another idea ?

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
fonik



Joined: Jun 07, 2006
Posts: 3759
Location: Germany
Audio files: 23

PostPosted: Wed Sep 12, 2012 12:06 am    Post subject: Reply with quote  Mark this post and the followings unread

diablojoy wrote:
hmm one slightly annoying limitation
the CD4051 will switch bipolar signals but is limited to around +/-7.5 volts
in that case the chip must be supplied +/- 7.5 volts on the VDD and VEE pins respectively but in that case it will not be able to switch a +10v
signal such as a gate or reset . If VDD is supplied with +15v and VEE is at ground then gate , reset or clock signals could be switched, which is fine for the original topic but you can then no longer switch bipolar signals
If to be used for a CV addressable switch module this is quite limiting indeed
To get around this so far my only thought is to use the CD4051 I/O's to switch a pair of DG412 chips instead of doing the signal switching directly.
but it does add some more complication to the circuit
Anyone have another idea ?

one could just use diodes for protection/limitation. who needs 10V gates anyways?

_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Wed Sep 12, 2012 1:22 am    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
one could just use diodes for protection/limitation. who needs 10V gates anyways?


Need Confused perhaps not however i have gear that puts out 10 volt clock and gate signals [M2C as an example] and modules that happily accept that as an input as i believe many others do as well
limiting to 7.5 volt signals may be acceptable for 99% of what is out there
but it is touch and go for triggering cmos powered at 15v with out front ending it first, I know you cover that with your designs matthias but that
may not always be the case with others.

with my previously mentioned matrix sequencer idea it isnt an issue at all the levels involved are known and can be accounted for quite
easily, only one would be bipolar and that is well within the 15 v peak to peak for the other 3 the CD4051 can just be powered from 15v with VEE tied to ground and it wont matter.

For a CV addressable switch where i dont know who is putting what into where however i thought to try and cover as many variables as possible
then again as you correctly say who needs 10 volt gates perhaps i am trying a little too hard at covering all the bases and being a little too paranoid about it Laughing
protection diodes do sound good and easy .
edit: hmm the data sheet just says 15 volt peak to peak but only shows an example for +/- 7.5 volt supply for bipolar use, makes me wonder if a CD4051 will work with a offset supply with VDD at +10v and VEE at -5v but would VSS then still be at 0v - GND ?

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
Dave Kendall



Joined: May 26, 2007
Posts: 413
Location: England
Audio files: 3

PostPosted: Wed Sep 12, 2012 4:29 am    Post subject: Reply with quote  Mark this post and the followings unread

Hi there.

Sorry for the silence - been a bit busy this end....
Simplest way might be with a DG408 - it's a 44V(!) version of the 4051. Smile

cheers,
Dave


DG408 VISH.pdf
 Description:

Download
 Filename:  DG408 VISH.pdf
 Filesize:  241.01 KB
 Downloaded:  52 Time(s)


_________________
"The Higgs Bosun's finally been found. So where's the Higgs Captain?"
Back to top
View user's profile Send private message
fonik



Joined: Jun 07, 2006
Posts: 3759
Location: Germany
Audio files: 23

PostPosted: Wed Sep 12, 2012 12:21 pm    Post subject: Reply with quote  Mark this post and the followings unread

cheers, dave! that's a good find! and the price is okay for some DIY: about 3.50 EUR here at rs-components.
_________________
Posted Image, might have been reduced in size. Click Image to view fullscreen.
cheers,
matthias
____________
fonitronik at
FlickR (pix) / SoundCloud (sounds) / YouTube (vids) / Vimeo (vids) / facebook (news)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Wed Sep 12, 2012 2:23 pm    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
Simplest way might be with a DG408 - it's a 44V(!) version of the 4051.


Damn Dave you really are good Smile No make that brilliant !
will have a look over the datasheet tonight thanks again.

edit : Twisted Evil must be my birthday [ 666 ]

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 878
Location: Lancashire, England
Audio files: 14

PostPosted: Thu Sep 13, 2012 9:11 am    Post subject: Reply with quote  Mark this post and the followings unread

diablojoy wrote:

edit : Twisted Evil must be my birthday [ 666 ]

While I was out walking just before I saw a bus with the number "666" Laughing

As for that high voltage multiplexor, read closely, I think it says somewhere that it's ground can only be 24 V below V+.

_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Thu Sep 13, 2012 3:21 pm    Post subject: Reply with quote  Mark this post and the followings unread

Quote:
As for that high voltage multiplexor, read closely, I think it says somewhere that it's ground can only be 24 V below V+.

Hi JingleJoe
Its referenced from V- and is a max value only
with +/-15 volt supply it will all be fine
in that case GND will be at 0V
If I am understanding it correctly it is the maximum to be taken into consideration perhaps mostly for in the case of when a single positive supply is used where the V- pin is tied to GND for switching larger positive voltage only signals , in that case the GND pin becomes a virtual GND and will need to be at a + voltage decided by the value supplied to the V+ pin.
So if V+ is at +44V and V- is at 0V then GND pin will need to be at a minimum of +20V but also no more than +25V . The half way point would be what is being aimed at here.
edit : To put it another way, once the positive supply to V+ pin exceeds +24V the GND pin must be supplied a positive voltage to keep up.
So the chip does cover a lot of possible ranges.

666 no longer. oh well

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
delayed



Joined: Jun 24, 2008
Posts: 129
Location: TN

PostPosted: Fri Sep 14, 2012 12:39 am    Post subject: Reply with quote  Mark this post and the followings unread

just subing to this to see how it turns out
Back to top
View user's profile Send private message
JingleJoe



Joined: Nov 10, 2011
Posts: 878
Location: Lancashire, England
Audio files: 14

PostPosted: Fri Sep 14, 2012 1:41 am    Post subject: Reply with quote  Mark this post and the followings unread

diablojoy wrote:

If I am understanding it correctly it is the maximum to be taken into consideration perhaps mostly for in the case of when a single positive supply is used where the V- pin is tied to GND for switching larger positive voltage only signals , in that case the GND pin becomes a virtual GND and will need to be at a + voltage decided by the value supplied to the V+ pin.
So if V+ is at +44V and V- is at 0V then GND pin will need to be at a minimum of +20V but also no more than +25V . The half way point would be what is being aimed at here.
edit : To put it another way, once the positive supply to V+ pin exceeds +24V the GND pin must be supplied a positive voltage to keep up.
So the chip does cover a lot of possible ranges.

Yes Smile
diablojoy wrote:

666 no longer. oh well

All things are fleeting.

_________________
As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"


Green Dungeon Alchemist Laboratories
Back to top
View user's profile Send private message
diablojoy



Joined: Sep 07, 2008
Posts: 795
Location: melbourne australia
Audio files: 11

PostPosted: Fri Sep 14, 2012 3:49 am    Post subject: Reply with quote  Mark this post and the followings unread

Delayed wrote
Quote:
just subing to this to see how it turns out

I expect at least a couple of projects could come from this so i am reasonably confident it will turn out very well,
I would be surprised if matthias or dave did not come up with something from it quite soon, certainly quicker than i am likely to anyway.
However my final goal is for a bigger project which i have had in mind for several years so i will be pursuing this for as long as it takes.
first thing is to come up with a working prototype 8 way CV controlled switch
I have now made a start at least, most of the basic schematic is sorted
and I ordered the required chips as of yesterday, its now down to details ....of course the devil is in the details and i am not so fast . I will start a new topic when i have something or perhaps Matthias or dave will, any way it goes i feel good Very Happy

_________________
In an infinite universe one might very well
ask where the hell am I
oh yeah thats right the land of OZ
as good an answer as any
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: jksuperstar, Scott Stites, Uncle Krunkus
Page 2 of 2 [39 Posts]
View unread posts
View new posts in the last week
Goto page: Previous 1, 2
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
e-m mkii

Please support our site. If you click through and buy from
our affiliate partners, we earn a small commission.


Forum with support of Syndicator RSS
Powered by phpBB © 2001, 2005 phpBB Group
Copyright © 2003 through 2009 by electro-music.com - Conditions Of Use