watts? Volts? 7331 '7ectronics FAQ

[Martin Naef]

Hi Kai,

On 05.01.2012 01:18, K9 Kai Niggemann wrote:
> with zener diodes, what does the watt number mean?
>
> I have one that is 1.3 W, in the schematics it's listed as a 1W. Is
> this important? they are both 9.1V

In this context, this essentially defines how much energy the diode can 
dissipate before it overheats and dies. So in theory, you can safely 
replace a 1W diode with a 10W one. In reality, they might have slightly 
different characteristics elsewhere that could influence your sound 
(depending on where they are used).


> And:
> With caps, what does the volt number tell me?

Same thing - it's a maximum rating before it blows up.

The one thing to consider is that components with higher ratings tend to 
be physically larger. At some point, they might no longer fit onto the PCB.

> in my book it doesn't even reference the watts of a diode, so I'm
> guessing it's negligible? it says "don't substitute" (because it will
> influence the sound. In the schematics it's a 1N4739A (Jameco part#:
> 178837). I have this
> one:<http://www.reichelt.de/Z-Dioden-1-3W/ZD-9-1/index.html?;ACTION=3;LA=444;GROUP=A422;GROUPID=2994;ARTICLE=23103;START=0;SORT=artnr;OFFSET=500;SID=12Tu6UrH8AAAIAACpKdbU0e58b69190d86ba957598e04aba4f9fa>.
>
>  am I in trouble?

You can be pretty sure that you won't blow up anything. The Reichelt 
page doesn't say much about the details of the part, it's hard to 
compare against the suggested part. So depending on what the function of 
the Zener is in this context, it may influence the sound.

Martin