[sdiy] Power distribution board

[Seb Francis]

Laurie Biddulph wrote:
>
> Some systems, like Eurorack, offer the option of a 3rd power rail 
> which is assigned to 5V. This solution minimises heat dissipation 
> through high voltage drops to the 5V rail but does increase the 
> potential (pun!) for voltage drops which are far more critical on 5V 
> circuits. Given the number of modules that actually need a 5V supply I 
> would say that it makes far more sense to do the regulation on board, 
> when and where it is needed. This will increase the loading on the 
> (usually) positive rail but this is a small price to pay.
>

I wouldn't say that "voltage drops are far more critical on 5V 
circuits".  Generally such circuits are digital and likely less 
critical.  Bear in mind also that microprocessor based modules can take 
a lot of 5V current ... perhaps 200mA+ for a fast processor and 
associated components.

If planning to include any microprocessor based modules (for example 
some of the newer MOTM modules) then it's definitely worth considering a 
dedicated 5V supply.

Seb