Film-Tech Cinema Systems
Film-Tech Forum ARCHIVE


  
my profile | my password | search | faq & rules | forum home
  next oldest topic   next newest topic
» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » BACP red reader problem

   
Author Topic: BACP red reader problem
Josh Jones
Redhat

Posts: 1207
From: Plano, TX
Registered: Apr 2000


 - posted 01-12-2008 02:59 PM      Profile for Josh Jones   Author's Homepage   Email Josh Jones   Send New Private Message       Edit/Delete Post 
A theater I'm currently servicing is have problems with their BACP reader in a Simplex XL sound head with Super Simplex atop. Cell outputs are wired together and driving a Toa PA amplifier. The playback audio will pop, click, and sometimes exhibit static. I could duplicate the complaint by tapping on the led bracket. After this discovery, I cleaned the face of the LED and the bi-pin header that plugs into the bracket. The problem still persists, but is much less pronounced.

So I guess what I'm asking is, was there a bad run of these, or is this a common problem that anyone has heard of before. My next attack I suppose would be to hook a scope up to the LED line and see if the voltage jumps while the bracket is tapped, indicating an intermittent connection to the LED.

Josh

 |  IP: Logged

Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 01-13-2008 12:57 AM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
You may want to put two summing resitors in the cell outputs

 |  IP: Logged

Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003


 - posted 01-13-2008 12:58 PM      Profile for Sam D. Chavez   Author's Homepage     Send New Private Message       Edit/Delete Post 
If the noise or static happens more or less all the time (so one can catch it happening) I would block the light coming from the LED into the lens. If the noise is still there, you can pretty much rule out the LED without the use of a scope. The impedance of the LED is so low, the scope won't tell you much anyway.

Assuming no loose wiring or bad grounding, most problems within these readers have to do with the solar cell itself. or the mini backplane inside the reader.

 |  IP: Logged



All times are Central (GMT -6:00)  
   Close Topic    Move Topic    Delete Topic    next oldest topic   next newest topic
 - Printer-friendly view of this topic
Hop To:



Powered by Infopop Corporation
UBB.classicTM 6.3.1.2

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.

© 1999-2020 Film-Tech Cinema Systems, LLC. All rights reserved.