Author Topic: Why volatge is changing? Fixing power supply.  (Read 853 times)

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Offline nadona

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Why volatge is changing? Fixing power supply.
« on: January 21, 2015, 12:48:25 am »
I am fixing the power supply of LeCroy LC584AL oscilloscope.

It is a switch mode power supply which outputs several voltages.

The problem is -15V output is changing to -21V in about 5 minutes and and keep going lower about 1mV per 10 seconds. I turned off after 10 minutes. If the scope is turned off when it gets over -21V then I have to wait a few hours to turn on the scope again. If I turn on the power supply right after it starts a few mV below where it turned off.

What component behave in the switch mode power supply this way when it goes to bad?

Thank you very much in advance.

[Edit] Incorporated the definition of "moment" & "slowly" :-DD
« Last Edit: January 21, 2015, 02:42:36 am by nadona »
Ha-ha-ha. That's good, too!
 

Offline c4757p

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Re: Why volatge is changing? Fixing power supply.
« Reply #1 on: January 21, 2015, 12:49:33 am »
Define "moment" and "slowly".
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline nadona

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Re: Why volatge is changing? Fixing power supply.
« Reply #2 on: January 21, 2015, 12:56:21 am »
Define "moment" and "slowly".

Sorry.
Incorporated the definition of "moment" & "slowly" into my original post.
Thank you for pointing it out. :-+
« Last Edit: January 21, 2015, 03:05:32 am by nadona »
Ha-ha-ha. That's good, too!
 


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