[time-nuts] Thunderbolt Supply

[Bruce Griffiths]

Kevin Rosenberg wrote:
> On Feb 11, 2011, at 9:44 PM, Neville Michie wrote:
>    
>> [...]For the minus 12v I used a ICL7662, these are rare, so a cmos gate oscillator and diode pump negative generator could be used. I am told the -12V is quite uncritical.[...]
>>      
> Thanks for the thoughts. I'm thinking about redoing the power supplies for my T-bolts.
> So, your comments are helpful.
>
> May I ask where is the ICL7662 rare? Digikey has over 20K in various forms.
>
> I've also heard that the 5V supply is not noise critical. For your minimum power goal,
> I imagine that's why you used a switcher rather than lose up to 0.4A x 7V (2.8W) using
> a linear 5V regular off the +12V line.
>
> Kevin
>
>
>    
You could look at using a variant of the Cuk switching regulator.
These can have relatively low input and output noise before any 
additional filters that may be added.

Bruce