Resistors/Capacitors experience

[Matthew Jacobs]

Hi Joel

As far as volts on capacitors go, you can always go above but never below.

So, let's say the schematic specifies 100V, it's OK to use anything above, like 200V, 400V or 600V, but not anything below like 50V.

The thing to remember is the higher the Volt rating the bigger the capacitor, so you may need to keep that in mind if space, on the PCB for example, is an issue.

J

 

[audiovisceral]

kiwames cost $1-$2

As far as I've heard, Kiwame carbon films are marked up, rebadged KOA Speer's. You can get the same product cheaper buying them directly from Mouser.

http://www.mouser.com/KOA-Speer/Passive-Components/Resistors/Power-Resistors/_/N-2gra1Z1z0zlrr?Keyword=carbon+film

 

[Joelv]

Thanks guys,

Matthew - What about resistors, does the same thing apply, that I can go higher but not lower and I should watch out for the size?


-Joel

 

[lassoharp]

On wattage - correct, safe to go higher - don't underrate.  Usually easy to tell if you've miscalculated - the resistor will fry.

For the cost of common value/usage resistors like 100K, 10K etc,  you can cover your bases well by buying bulk in 1 or 2W ratings.  That way you're covered for higher dissipation apps.  No harm in using a 1 W in 1/4W scenario.  Just stay aware of the physical size considerations - usually not a problem with metal oxides, carbon or metal films but definitely an issue with carbon comps on pcbs. 

Also, if you use a standby switch on the PS,  you should be able to use lower voltage coupling caps if you find some types you really like that aren't rated for the full peak PS voltage

 

[QUEEF BAG]

lassoharp-

so, increasing the wattage of resistors, I do that a lot, except current limiting resistors, or other what
i think of as "saftey" resistors feeding power to a circuit, they burn up and circuit is no longer pulling
current.  And those quarter watt 47 ohm resistors right before the output tanny on a 550a eq?  I think those are there so they burn and the tranny doesn't when a 2520 sh*ts the bed. 

At least that's what i'm thinking at the moment, till someone corrects me (which shouldn't take long). 

 

[lassoharp]

I'm not familiar with the 550a circuit but yeah, if it's in there in a protective capacity of some sort I'd stay on spec or undersize if it meant the possibility of frying a winding.

 

[Adky]

Elnas Silmic II don't have anything higher then 100V not as i know atleast.  if you need that high , try those alumnium nichicon cap, they are in silver color and also really nice up to 450V