[sdiy] Polyfuse Tripping Current values

[Graham Atkins]

On 10 Jan 2011, at 16:12, Justin Owen wrote:

> Hey all,
>
> Belated Christmas & HNY wishes to everyone - hope you all had good/ 
> fun/safe (or recoverable...) times.
>
> Based on the advice I've had here I'm going to add polyfuses to this  
> power supply breakout module I'm working on.
>
> My Analogue Systems rack has each rail divided into 3 busses - each  
> with a 1A fuse on, my Doepfer rack uses a single 400mA fuse on the  
> mains transformer AFAIK.
>
> So, first up - considering a) that I'd like to build a breakout  
> module for each rack and b) that I've no idea what current draw the  
> prototype circuits that might be powered off it will have - what  
> Tripping Current should I specify for the Polyfuse to be  
> *reasonably* safe?
>
> ...and secondly, is there a rule of thumb for specifying a Tripping  
> Current for a circuit that I *do* know the current draw of?

You build the racks first thern measure the current draw, you can't  
"specify" something unknown.

Graham