![]() |
|
|
Thread Tools | Display Modes |
|
![]() |
#1 |
CapXon Be Gone
Join Date: Sep 2011
City & State: Idaho
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hardcore Geek
Posts: 3,216
|
![]() So I disappeared from working on electronics for quite some time. I'm unboxing my ancient projects and want to resume some of them. Unfortunately, my knowledge is a little rusty.
I've always liked to do full recaps on power supplies. My cap supply isn't perfect and I do not have any more 0.47µF 50V caps. I do have some ceramic caps with that value. Can they replace the lytic without issues? If I remember correctly, their max voltage drops rapidly after getting hot. Is that correct? If this isn't a good idea, I doubt the cap will cause any problems. It's by the main controller/exhaust so I doubt it will get hot or fail but I like to be thorough. |
![]() |
![]() |
![]() |
#2 |
Great Sage 齊天大聖
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 26,681
|
![]() most ceramics are 60% tolerance.
i use polyester or polypropylene for 1uf and under. |
![]() |
![]() |
![]() |
#3 |
Super Moderator
Join Date: Jul 2005
City & State: ----
My Country: Sweden
Line Voltage: 230v 50Hz
I'm a: Knowledge Seeker
Posts: 5,138
|
![]() Ceramic capacitors capacitance are also voltage dependent.
So the general answer to this question would be no, you can't.
__________________
"The one who says it cannot be done should never interrupt the one who is doing it." |
![]() |
![]() |
![]() |
#4 |
Badcaps Veteran
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,387
|
![]() If you can get same value/voltage CGO ceramics, you won't have to worry about the temperature or voltage coefficients. If X7R, then the combined tolerance will be, IIRC, +/-20%. Z5U and Y5V are crap, IMO.
That said, the impedance characteristic will be very different from lytics.
__________________
PeteS in CA Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells. **************************** To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it. **************************** Anti-Covid-Vaxxer pig crap claim/prediction, Doctor: Heart Failure from mRNA Jabs "Will Kill Most People" | Principia Scientific Intl. ; Dr. Geert Vanden Bossche Warns COVID-19 Jab Injuries and Deaths Will Soon "Collapse Our Health System" (VIDEO) ; Fully Vaxxed May 2021; Since that time I've done 7 5Ks, 1 8K, 8 10Ks, and 4 half marathons |
![]() |
![]() |
![]() |
#5 |
CapXon Be Gone
Join Date: Sep 2011
City & State: Idaho
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hardcore Geek
Posts: 3,216
|
![]() Thanks for the replies. I couldn't find anything suitable in my parts bin. I think I will just leave the cap where it is. All the other higher value caps will be replaced which should be good enough.
|
![]() |
![]() |
![]() |
#6 |
Badcaps Veteran
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,387
|
![]() Ack! COG, not "CGO".
|
![]() |
![]() |
![]() |
#7 |
Solder Sloth
Join Date: Nov 2012
City & State: CO
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 7,165
|
![]() but it is NP0?
|
![]() |
![]() |
![]() |
#8 |
Badcaps Veteran
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,387
|
![]() "COG" and "NPO" are the same thing, probably nomenclature going back more decades than I do (I think I saw the terms used in late 1950s vintage TV technician magazines).
|
![]() |
![]() |
![]() |
#9 |
Solder Sloth
Join Date: Nov 2012
City & State: CO
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 7,165
|
![]() oh I was jusr being silly with O's and 0's, you know my username...
![]() |
![]() |
![]() |
![]() |
#10 |
Badcaps Veteran
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,387
|
![]() |
![]() |
![]() |
![]() |
#11 |
CapXon Be Gone
Join Date: Sep 2011
City & State: Idaho
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hardcore Geek
Posts: 3,216
|
![]() I needed to order parts for something else so I just ordered some 0.47µF 50V nichicon UPW
![]() |
![]() |
![]() |
![]() |
#12 |
Solder Sloth
Join Date: Nov 2012
City & State: CO
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 7,165
|
![]() 000000k it is
![]() |
![]() |
![]() |
![]() |
#13 |
Badcaps Veteran
Join Date: Jan 2011
City & State: New Jersey
Posts: 449
|
![]() If you want to visualize how capacitance drops with applied DC bias voltage, you can check out Kemet's KSIM web app:
https://ksim3.kemet.com/capacitor-simulation The limitation is fundamentally package size, and more directly, the physical amount of dielectric material contained. Since Class II ceramics are ferroelectric, they "saturate" similar to how an inductor's core might. More material means it saturates less under the same DC bias conditions. Beware of "too good to be true" capacitance values in tiny packages. Sure you can get a 1.0uF/25V 0603 capacitor, but you better not use it above 5V, if you really need a 1.0uF capacitor. |
![]() |
![]() |
![]() |
#14 |
CapXon Be Gone
Join Date: Sep 2011
City & State: Idaho
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hardcore Geek
Posts: 3,216
|
![]() Thanks for the link, that's a pretty useful tool
![]() |
![]() |
![]() |
![]() |
Thread Tools | |
Display Modes | |
|
|