[Cheungcf]

Hi! I'm planning to change the capacitors of some boards of my 9500LC from 85 degree C to 105 degree C in order to get better performance. However I can't find the replacement of 47uF 385V capacitor on the HDM. I can only get 47uF 400V 105 degree C cap from the local supplier. Is it ok to replace the cap with higher voltage?


Also I can't get the 75 ohm 3W metal oxide resistor to replace the carbon resistor on the board of LVPS. Can I use 75 ohm 2.5W resistor for the repalcement?


Thanks.


Cheung

 

[Ile]



Quote:
Originally Posted by Cheungcf /forum/post/16946158


I can only get 47uF 400V 105 degree C cap from the local supplier. Is it ok to replace the cap with higher voltage?

Yes it's ok to use higher max voltage value.

Quote:
Originally Posted by Cheungcf /forum/post/16946158


Also I can't get the 75 ohm 3W metal oxide resistor to replace the carbon resistor on the board of LVPS. Can I use 75 ohm 2.5W resistor for the repalcement?

I think it's not good idea to use metal oxide resistor to replace the carbon resistor. Those aren't not so good for circuitry associated with surges, high peak power or high energy.


Use Ohmite ceramic composition resistors for carbon composition resistors replacement.
http://www.ohmite.com/cgi-bin/showpa...t=ox_oy_series


Use two 150 Ohm 2W Ohmite OY resistors in parallel to get 75 ohm and 4W power handling.

 

[nashou66]



Quote:
Originally Posted by Ile /forum/post/16946213


Yes it's ok to use higher max voltage value.


I think it's not good idea to use metal oxide resistor to replace the carbon resistor. Those aren't not so good for circuitry associated with surges, high peak power or high energy.


Use Ohmite ceramic composition resistors for carbon composition resistors replacement.
http://www.ohmite.com/cgi-bin/showpa...t=ox_oy_series


Use two 150 Ohm 2W Ohmite OY resistors in parallel to get 75 ohm and 4W power handling.

Actually on the newer LVPS the carbon comp resistors he talks about are changed with the metal oxide. So far i have not had a problem and they scoped better than the carbons did.

Marquee modifications and Performance enhancement


Athanasios