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
  EdisonRex Edison's Electronic Review
Please visit the chat
 Forum index » DIY Hardware and Software » YuSynth
Problem with Yusynth Sequential router
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [5 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
Author Message
prgdeltablues



Joined: Sep 25, 2006
Posts: 178
Location: UK
Audio files: 11

PostPosted: Sun Feb 23, 2014 5:55 am    Post subject: Problem with Yusynth Sequential router Reply with quote  Mark this post and the followings unread

Hi,

Having problems with the reset function on my Sequential router build. Neither the reset push button nor the reset input work properly - strangely, they actually cause the sequence to advance, though not in a consistent manner. Resetting via the reset positions on the rotary switches works fine, and the circuit otherwise behaves properly.

I can't find any build errors or solder shorts, but can check again (and again).

Applying 12V momentarily (I'm running off +/- 12V) to either side of D5 causes a reset OK, as does applying it to the junction of C4 and R16. Applying 12V to reset in does nothing. Applying it to the other end of R13 causes the erratic advancing behaviour. That makes me wonder if there is something going on with a current surge through C10 and C9 into the shifting circuitry?

The only value changes I've made are 1MEG for R4 instead of 1M2, 240R for R7, and 4k7 for R15 (the latter since spice modelling suggested on 12V, the output of the reset npn circuit was rather a low voltage spike compared to 15V operation). I can't see that any of these should cause the problem.

Any suggestions?

Peter
Back to top
View user's profile Send private message
Benjamin AM



Joined: Nov 04, 2010
Posts: 68
Location: Boise

PostPosted: Sun Feb 23, 2014 7:26 am    Post subject: Reply with quote  Mark this post and the followings unread

My suggestion might be to triple check that you are using the correct transistors BC547c(NPN) for Q3 and Q4. At my house, PNPs have been known to sneek their way into my BC547 and 2n3904 component drawers. One more thought, Are you using a Normally Open Push Button for the reset?
Back to top
View user's profile Send private message
prgdeltablues



Joined: Sep 25, 2006
Posts: 178
Location: UK
Audio files: 11

PostPosted: Sun Feb 23, 2014 9:40 am    Post subject: Reply with quote  Mark this post and the followings unread

Thanks for the suggestions. Checked and they are both BC547s. Button is normally open.

The plot thickens. Tested it more with the reset button/input disconnected. Works except that switch 4 reset makes it alternate just between 1 and 2 - setting switches 5 or 6 to reset as well, then makes it behave properly, sequencing 1-2-3-1-2-3-etc. All other reset settings on switches 2-6 behave as they should. I'm stumped.

Peter
Back to top
View user's profile Send private message
yusynth



Joined: Nov 24, 2005
Posts: 1224
Location: France

PostPosted: Fri Feb 28, 2014 10:28 am    Post subject: Reply with quote  Mark this post and the followings unread

Don't search this external reset circuit is badly designed, I must redesign it.
_________________
Yves
Back to top
View user's profile Send private message Visit poster's website
prgdeltablues



Joined: Sep 25, 2006
Posts: 178
Location: UK
Audio files: 11

PostPosted: Fri Feb 28, 2014 3:58 pm    Post subject: Reply with quote  Mark this post and the followings unread

Thanks, Yves.

I have eventually got it sort of working, after trying various things, including reducing the value of the series input resistor down to 10k, which worked for the external input but did nothing for the push button switch, I tried removing c10, the 100n cap across the switch. I also connected the switch to V+ through its own 1k resistor to stop the coupling to the clocking circuit. That seems to have done it, though it is still rather temperamental. The problem seems to be that the voltage pulse doesn't always reach the threshold to trigger the reset.

I must admit I couldn't quite work out what the circuit was intended to do. it seems to be a combination of debounce, gate to trigger, and Schmidt trigger?

it's a nice module though, very neat effect.

peter
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic Moderators: Scott Stites
Page 1 of 1 [5 Posts]
View unread posts
View new posts in the last week
Mark the topic unread :: View previous topic :: View next topic
 Forum index » DIY Hardware and Software » YuSynth
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