LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #2   Report Post  
Old January 18th 05, 06:59 PM
sofie
 
Posts: n/a
Default

Henry:
As long as it is still w"working" the problem is not likely anything more
than either cold or cracked solder connection OR electrolytics that have
dried out or have developed high ESR. If you do not have an ESR meter then
you will have to use the "one by one" substitution method... or just replace
all of the electrolytics at once. Just about all other methods of testing
electrolytics will not provide the crucial ESR test needed especially for
electrolytics in switching power supplies and other high frequency or
critical circuitry.
DO NOT keep running your power supply with this problem.... it will only get
worse to the point that it will fail all together and be a much more
involved repair.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -



"Henry Kolesnik" wrote in message
om...
This is a 20 amp switching power supply for their 12 volt ham

transceivers.
I used to leave it on 24 hours a day on receive pulling less than an amp
with no problems but about a month ago it started to shut off. You have

to
turn it off first and wait about 15 minutes and it'll come back on,
sometimes for an hour or longer and other times for 5 to 10 minutes.

After
it goes down you have to turn it off and then wait 10 to 15 and it'll come
back for an unpredictable time. It doesn't seem matter if it been on for

an
hour or sometime 5 minutes, it'll shut down. It doesn't seem to be a cold

or
heat problem and flexing the board or tapping components won't turn it

off
or make it come on quicker. I don't have a schematic and can't find one.
It must have some kind of logic that senses something and makes it shut

down
and then time out. One thing I have noticed is that if I turn it on when
its not ready to come on I can hear a very, very faint noise (like static
discharge) that goes away as soon as the switch is turned off. It has a
TL494CN. Any tips appreciated.

--

73
Hank WD5JFR




 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
fs: Kenwood kpt50 repeater radio programmer Skipp has Kenwood stuff Homebrew 2 August 14th 20 06:12 PM
fs: Kenwood kpt50 repeater radio programmer Skipp has Kenwood stuff Equipment 2 June 16th 06 04:22 PM
fs: Kenwood kpt50 repeater radio programmer Skipp has Kenwood stuff Equipment 0 August 7th 03 06:16 PM
fs: Kenwood kpt50 repeater radio programmer Skipp has Kenwood stuff Homebrew 0 August 7th 03 06:16 PM
Address the issues, Skippy! Repost #3 Skipp would rather be back in Tahoe CB 5 July 30th 03 07:05 PM


All times are GMT +1. The time now is 05:09 PM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017