[time-nuts] Thunderbolt Supply

[Neville Michie]

One approach for the Tbolt is to use a low dropout low noise linear  
regulator (I used a LT1764 set to 11.5 volts) for the 12 volt input  
(it is within spec) and a 5V switcher (Recom R-785.0-1.0) for the 5v.  
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.
The whole lot runs across a 12V lead acid accumulator which delivers  
about 300mA to run it when the power fails. The battery is floated at  
14.0 volts with a linear regulator from a mains transformer power  
supply.
A 20 AH battery gives more than 2 days backup. As the 12Volt is the  
sensitive input, the linear regulator should keep the noise down. The  
whole setup is designed to use minimum power.
cheers, Neville Michie



On 11/02/2011, at 10:16 AM, Larry McDavid wrote:

> Greetings! I am a new member of the mail list. I've been using a HP  
> Z3801A GPS-steered standard but have just acquired a Trimble  
> Thunderbolt GPS Disciplined Clock.
>
> I'm seeking a recommendation for a power supply for this  
> Thunderbolt receiver. There is much discussion about noise from  
> some switching supplies and the effect on phase noise of the 10 MHz  
> output. The Thunderbolt manual specifies the following supply and  
> loads:
>
> +12 vdc  750 mA
> + 5 vdc  400 mA
> -12 vdc   10 mA
>
> This combination is somewhat unusual in that the highest current is  
> on the 12 volt output rather than the 5 volt output. I'm asking if  
> list members have a favorite power supply for this unit, why and  
> where I can obtain one.
>
> -- 
> Best wishes,
>
> Larry McDavid W6FUB
> Anaheim, CA  (20 miles southeast of Los Angeles, near Disneyland)
>
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