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
  Rob Adventures in Sound
Please visit the chat
 Forum index » DIY Hardware and Software » Jürgen Haible designs
JH Varilogic problem
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
AnalogCustom



Joined: Jun 23, 2009
Posts: 49
Location: Chile

PostPosted: Thu Sep 03, 2009 12:02 am    Post subject: JH Varilogic problem Reply with quote  Mark this post and the followings unread

Hello:
Transistors in red circle, very hot.
If input A = High and B = Low, both LEDs are ON.
Equally If input A = Low and B = High, both LEDs are ON.

What will be the problem?

The model used is:

2N4401 (NPN)
2N4403 (PNP)

Thank you.

Marco.


VARILOGIC.JPG
 Description:
 Filesize:  102.28 KB
 Viewed:  148 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

VARILOGIC.JPG



_________________
http://analogcustomsynth.blogspot.com/
http://sites.google.com/site/analogcustomsynth/
http://www.youtube.com/user/AnalogCustomSynth
Back to top
View user's profile Send private message Send e-mail Visit poster's website
jhaible



Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24

PostPosted: Thu Sep 03, 2009 2:16 am    Post subject: Reply with quote  Mark this post and the followings unread

Wrong pinout?

JH.

_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
AnalogCustom



Joined: Jun 23, 2009
Posts: 49
Location: Chile

PostPosted: Thu Sep 03, 2009 8:20 am    Post subject: Reply with quote  Mark this post and the followings unread

jhaible wrote:
Wrong pinout?

JH.


Hello:
Pinout is correct.

I attached a new file

Thanks.

Marco


VARILOGIC.JPG
 Description:
 Filesize:  103.11 KB
 Viewed:  149 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

VARILOGIC.JPG



_________________
http://analogcustomsynth.blogspot.com/
http://sites.google.com/site/analogcustomsynth/
http://www.youtube.com/user/AnalogCustomSynth
Back to top
View user's profile Send private message Send e-mail Visit poster's website
jhaible



Joined: May 25, 2007
Posts: 2014
Location: Germany
Audio files: 24

PostPosted: Thu Sep 03, 2009 9:38 am    Post subject: Reply with quote  Mark this post and the followings unread

Ha, I have an idea. The transistor whose base is switched to GND will go into zener mode when its BE junction is reverse-biased!

Funny I never noticed this in all these years in my JH-3 synth. Maybe a current limit from the on-board regulators prevented heating.

Cure: Put a 1N4148 diode in series with each emitter of these two transistors.

JH.

_________________
"I tell you the truth, if anyone says to this mountain, 'Go, throw yourself into the sea,' and does not doubt in his heart but believes that what he says will happen, it will be done for him. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours." (Mk 11,23f)
Back to top
View user's profile Send private message Send e-mail Visit poster's website
AnalogCustom



Joined: Jun 23, 2009
Posts: 49
Location: Chile

PostPosted: Thu Sep 03, 2009 10:41 am    Post subject: Reply with quote  Mark this post and the followings unread

jhaible wrote:
Ha, I have an idea. The transistor whose base is switched to GND will go into zener mode when its BE junction is reverse-biased!

Funny I never noticed this in all these years in my JH-3 synth. Maybe a current limit from the on-board regulators prevented heating.

Cure: Put a 1N4148 diode in series with each emitter of these two transistors.

JH.


Hello. Thank Very much!! I noticed of overheating for the smell.



I attached a new scheme with diodes.

Now works correctly.

Thanks again for your help.

Marco.


hjvarlog MOD.JPG
 Description:
 Filesize:  98.11 KB
 Viewed:  146 Time(s)
This image has been reduced to fit the page. Click on it to enlarge.

hjvarlog MOD.JPG



_________________
http://analogcustomsynth.blogspot.com/
http://sites.google.com/site/analogcustomsynth/
http://www.youtube.com/user/AnalogCustomSynth
Back to top
View user's profile Send private message Send e-mail Visit poster's website
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 » Jürgen Haible designs
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