[time-nuts] Anybody want a Thunderbolt power supply?

[Jeff AC0C]

I bought a module off ebay for a project recently.  It has a LM317/LM337 
pair, small heat sinks, regulator, bypass caps, rectifiers and filtering 
caps all on one board for about $10 delivered.  To this you add a small 
transformer and piggy-back a 7805T/heat sink and that would give the 3 
voltages required by this unit.

Of course it's linear so it's got the linear heat dissipation issue but by 
the right pick of transformer that could be as low as about 3W (around 2KWH 
per month).  Then again, it's also got the linear noise "problems" which are 
pretty much zero.

73/jeff/ac0c
www.ac0c.com
alpha-charlie-zero-charlie

-----Original Message----- 
From: Bob kb8tq
Sent: Wednesday, August 31, 2016 7:49 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Anybody want a Thunderbolt power supply?

Hi

It is not that hard to do. Use a linear rather than a switching approach. 
Run the +12 and +5 supplies off of LT1764 regulators. The -12 is very low 
current, run it off of a low noise op amp. There are lots of toroidal line 
transformers that will drive something like this.

Bob

> On Aug 31, 2016, at 6:20 PM, Cube Central <cubecentral at gmail.com> wrote:
>
> Wow, given all the responses about the cleanliness of the power into a 
> Thunderbolt, I would be even more interested in a power supply that did 
> *not* leave the "last mile" up to me.  I would be more interested in a 
> "pretty clean" power supply that I could just plug in and go.  Any 
> thoughts of me actually wiring the last bit of it make me break out in a 
> cold sweat and come face to face with my (established, and sadly 
> slow-to-expand) limitations.
>
> Maybe I'm the only one that would be interested in such a solution?  I 
> hope not, but I can see that there is a lot to consider about such a 
> thing.
>
> Cheers!
>
>    -Randal
>        (at CubeCentral)
>
> -----Original Message-----
> From: time-nuts [mailto:time-nuts-bounces at febo.com] On Behalf Of Bob 
> Stewart
> Sent: Wednesday, 31 August, 2016 15:29
> To: Discussion of precise time and frequency measurement 
> <time-nuts at febo.com>
> Subject: Re: [time-nuts] Anybody want a Thunderbolt power supply?
>
> OTOH, how many time-nuts have any interest in paying for a power supply 
> that's up to time-nuts standards?  It's really not easy to bring a small 
> product to market at a small price.  Even if you completely discount the 
> personal effort of design, construction, and marketing, there's the issue 
> of packaging.  Without a package, it's just an amateur effort not worth 
> considering.  With a package, such as a Hammond box, the price moves into 
> new territory and nobody's interested.
>
> Bob
>
>
>      From: Charles Steinmetz <csteinmetz at yandex.com>
> To: time-nuts at febo.com
> Sent: Wednesday, August 31, 2016 4:24 PM
> Subject: Re: [time-nuts] Anybody want a Thunderbolt power supply?
>
> Mark wrote:
>
>> Some times a full linear supply is not a viable option due to power 
>> dissipation/size issues or the utter convenience of using a switching 
>> wall wart.
>
> In the context of the present discussion -- powering a Tbolt for time-nuts 
> use -- the first consideration would just be laughable and the second 
> would be nothing but terminal laziness.
>
> Best regards,
>
> Charles
>
>
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