[time-nuts] Anybody want a Thunderbolt power supply
dk4xp at arcor.de
Mon Sep 5 20:33:18 EDT 2016
Am 01.09.2016 um 06:56 schrieb Gerhard Hoffmann:
> Am 01.09.2016 um 05:35 schrieb Charles Steinmetz:
>> The suggestion to use LT3042s is a good one, but note that it has an
>> output current rating of 200mA. The Tbolt needs ~250mA at +5v, and
>> ~700mA at +12v [at startup -- but only ~150mA steady-state, depending
>> on ambient temperature]. LT3042s can be used in parallel, so two of
>> them for the +5v supply and four of them for the +12v supply would be
>> required. That isn't so bad for the +5v supply, but seems excessive
>> for the +12v supply (particularly when three of the four are needed
>> only during warmup from cold).
> I have made a stamp-sized layout for LT3042 + external npn power
> as shown in the data sheet.
> Not fabricated, let alone tested.
fabricated on a rainy Sunday and initially tested.
Output voltage is 5 Volts.
The preliminary noise spectrum is
without appropriate shielding, powered from R&S NGT20 @ 8V.
The faster than 1/f noise rise is caused by the pre-amplifier.
Still quite OK.
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