Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Notices

Go Back   Film and Darkroom User > Equipment > Darkroom

  ***   Click here for the FADU 2015/2014 Yearbooks   ***

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 9th July 2020, 10:54 AM
robinb robinb is offline
Friend
 
Join Date: Apr 2010
Location: London
Posts: 214
Default electronics help with devere 504 dicromat

hi

i have a problem with my devere 504 mk iv and 250w trans tan
it keeps blowing bulbs
not all the time but slot more than it used to

measuring the voltage across the lss as mp its 28v which seems a bit high for a 24v lamp but it might be just how they made them

can any of you electrically able people check the voltage across your lamp

Also if anybody has a circuit diagram for the transtab 250 that would be amazing

best

robin
Reply With Quote
  #2  
Old 10th July 2020, 05:50 AM
Chrisvclick Chrisvclick is offline
Friend
 
Join Date: Dec 2015
Location: Wales Uk, Gods Garden
Posts: 100
Default

Not got the same equipment, but would expect worse case scenario of +/- 10% of design frequency. More like +/- 5%. Off load that is. With bulb running then near spot on...
__________________
Is there a level below "in the poop" ?
Reply With Quote
  #3  
Old 10th July 2020, 06:37 AM
Bill's Avatar
Bill Bill is offline
Moderator & Keeper of the Calendar
 
Join Date: Sep 2008
Location: Barrow - in - Furness
Posts: 1,803
Default

A few years ago I had quick bulb failures and like you checked the voltage at the input in the Mk 4 head. Mine was 28V too. I cleaned up the pins on the lamp and also the sockets in the connector. Since then I have not had any problems. Also the quality of the lamps can alter the life. I was using lamps sold for disco lighting. Since then I have changed to known make lamps such as Osram or Philips and they seem to last better.
Reply With Quote
  #4  
Old 10th July 2020, 07:26 AM
robinb robinb is offline
Friend
 
Join Date: Apr 2010
Location: London
Posts: 214
Default

thanks for the reply’s

I’ll try cleaning up the pins and holder and see if that improves things
I use the Osram bulbs - i got a box of 12 15 years ago but have only changed twice till lockdown and have been thru 6 !

best
robin
Reply With Quote
Reply
Support our Sponsors, they keep FADU free:   AG Photographic   The Imaging Warehouse   Process Supplies   RH Designs   Second-hand Darkroom Supplies  

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Devere 203 99p paulc Auctions of Interest 0 12th October 2014 02:23 PM
devere 504 Andy Darkroom 9 8th January 2013 11:53 PM
Devere 504 BIN £250. vanannan Auctions of Interest 7 29th April 2012 06:34 PM
DeVere 504 MartyNL Auctions of Interest 0 17th March 2012 09:29 PM
Electronics expert help. vanannan Darkroom 6 26th October 2009 08:03 AM


All times are GMT. The time now is 08:01 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.