« previous next »
Pages: [1]   Go Down

Author Topic: Capacitor identification - Apogee Alta U4000 CCD camera  (Read 1573 times)

0 Members and 1 Guest are viewing this topic.

Offline flolicTopic starter

  • Frequent Contributor
  • **
  • Posts: 387
  • Country: hr
    • http://filiplolic.com/
Capacitor identification - Apogee Alta U4000 CCD camera
« on: January 14, 2020, 11:17:08 pm »
I am repairing old Apogee Alta U4000 CCD camera that has bunch of dead axial capacitors inside. Almost all of them has corroded positive terminal, to the point that + leg fall of when you try to desolder them.
Are those standard aluminium or tantalum?
Vishay ones are obviously replaced previously.
Capacitors are 68uF/16V.
Thanks,
Filip

« Last Edit: January 19, 2020, 08:41:14 am by flolic »
Logged
 

Offline andy3055

  • Super Contributor
  • ***
  • Posts: 1127
  • Country: us
Re: Capacitor identification
« Reply #1 on: January 15, 2020, 01:14:06 am »
They are standard Aluminum electrolytic caps.
Logged
 

Offline Pete66

  • Regular Contributor
  • *
  • Posts: 52
  • Country: us
Re: Capacitor identification
« Reply #2 on: January 16, 2020, 05:46:37 am »
Vishay ones appear to be bipolar.
Logged
 

Offline andy3055

  • Super Contributor
  • ***
  • Posts: 1127
  • Country: us
Re: Capacitor identification
« Reply #3 on: January 16, 2020, 05:56:29 pm »
By the way, the board has markings for the polarity of the caps. Pay attention to those when you do the replacements.
Logged
 

Offline flolicTopic starter

  • Frequent Contributor
  • **
  • Posts: 387
  • Country: hr
    • http://filiplolic.com/
Re: Capacitor identification
« Reply #4 on: January 16, 2020, 07:59:31 pm »
Thank you all.
I replaced all of them with good quality low esr 105C from Panasonic and camera is working fine (after installing new KAI4022 CCD sensor).
I used standard radial ones that I had, and bent one leg to the other side.

Logged
 

Offline free_electron

  • Super Contributor
  • ***
  • Posts: 8550
  • Country: us
    • SiliconValleyGarage
Re: Capacitor identification
« Reply #5 on: January 16, 2020, 08:50:09 pm »
old philips capacitors.
Logged
Professional Electron Wrangler.
Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline flolicTopic starter

  • Frequent Contributor
  • **
  • Posts: 387
  • Country: hr
    • http://filiplolic.com/
Re: Capacitor identification
« Reply #6 on: January 19, 2020, 08:39:56 am »
Anyone know how to properly purge sensor chamber with Argon? I replaced desiccant but anyway got some condensation on the CCD sensor.
Usually sensor is cooled to -20 to -30C.

There are two 1/4" 20TPI charging ports on the back side of camera, each have spring loaded ball check valve. Should I just pressurize chamber with Argon, or should I also connect vacuum pump on the other port?
It is my understanding that chamber should stay at positive Argon pressure relative to atmosphere to avoid air to leak back in. But how much pressure?


My camera obviously leaked through hermetic electrical connection feed through, because (sealing epoxy?) was partially unglued from the housing. Also there are some traces of corrosion.
« Last Edit: January 19, 2020, 08:44:22 am by flolic »
Logged
 

Offline flolicTopic starter

  • Frequent Contributor
  • **
  • Posts: 387
  • Country: hr
    • http://filiplolic.com/
Re: Capacitor identification - Apogee Alta U4000 CCD camera
« Reply #7 on: January 19, 2020, 07:16:25 pm »
Anyway, I successfully purged the chamber, no more condensation  :)

First I connected the vacuum pump to the suction port near the power and USB connectors and pulled the air from the chamber. Then I connected Argon bottle (via the pressure regulator) to the charging port and slowly let the gas in.
You can not "overfill" the chamber, any excessive pressure will vent out through the suction port.

My camera can now reach at least 60C temperature difference, before it was struggling with 50C  :)

Logged
 
Pages: [1]   Go Up
« previous next »

Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf

 


EEVblog Main Site EEVblog on Youtube EEVblog on Twitter EEVblog on Facebook EEVblog on Odysee