[TangerineSDR] DCC discussion list

[Scotty Cowling]

Hi Tom,

Option C is the easiest and in my opinion, only viable option. A wide 
range input that includes 11-15V allows multiple battery chemistries, 
while enabling common linear and switching bench supplies to be used. 
Ech locale knows best how to get this standard voltage from their local 
mains supply. And while we will do our best to filter the input power 
rail, if the user connects it to a noisy solar system, it beyond our 
scope to mitigate his interference issues.

The typical modern mixed-mode designs do what John A was describing: 
start with a wide-range noisy input, then regulate to a narrow-range 
less noisy but still not quiet enough intermediate voltage, then use 
LDOs and lots of filtering to get analog-quality 3.3V, 2.5V or 1.8V 
supplies. Keep the analog power separate from the digital power. Use 
series inductors and multiple-capacitor filters where necessary (they 
are small and inexpensive at low currents).  If you pick your 
intermediate voltage(s) properly, you can minimize the power dissipation 
of the linear regulators while still gaining the low-noise advantages of 
LDOs.

Every design should have clock tree and and power tree diagrams along 
with its block diagram.

73,
Scotty WA2DFI



On 9/13/2019 11:52 AM, Engelke, Bill via TangerineSDR wrote:
>
> Something to consider on this, for convenience of the user:   the 
> Odroid N2, which we are thinking is the likely SBC in the Tangerine, 
> runs on 12v also (not 5v).
>
>   * 73- Bill, AB4EJ
>
> *From:* TangerineSDR <tangerinesdr-bounces at lists.tapr.org> *On Behalf 
> Of *Tom McDermott via TangerineSDR
> *Sent:* Friday, September 13, 2019 8:29 AM
> *To:* Phil Erickson <phil.erickson at gmail.com>
> *Cc:* Tom McDermott <tom.n5eg at gmail.com>; TAPR TangerineSDR Modular 
> Software Defined Radio <tangerinesdr at lists.tapr.org>
> *Subject:* Re: [TangerineSDR] DCC discussion list
>
> HI Phil - We certainly will need requirements on power & distribution 
> characteristics.
>
> However I think we first may need a plan.
>
> Question 1: do we operate off:
>
> Option A: 120VAC input  (North America)
>
> Option B: 120-240VAC input (Worldwide)
>
> Option C:  + 12VDC input?    [ +12V means in my view  +10.5 to +13.8 
> VDC, allowing a battery to be the power input. ]
>
> In my view Option C is the easiest for project engineering, but 
> requires the user to generate +12V, battery charge, etc.
>
> Given the possible worldwide AC variables, battery type and size 
> variables, etc., it avoids many issues.
>
> If we were to choose Option C then, at the system level then:
>
> Question 2 how do we create needed voltages:
>
> Option 1. Data Engine regulates & distributes all the system voltages 
> from a single +12VDC  (11-13.8V) input.
>
> Option 2: Separate DC supply derives all the needed voltages from 
> +12VDC (11-13.8V) input.
>
> Option 3: Each module derives it's own voltages from a +12VDC 
> (11-13.8V) input.
>
> -- Tom, N5EG
>
> On Thu, Sep 12, 2019 at 7:00 PM Phil Erickson <phil.erickson at gmail.com 
> <mailto:phil.erickson at gmail.com>> wrote:
>
>     Hi Tom,
>
>       It is probably good for item 5 to think about whether
>     cleanliness specs for the power supply are required.  As you know,
>     hash on the DC lines could be a major RFI problem.  (Batteries
>     would tend not to have that issue, hence their mention earlier.)
>
>     73
>
>     Phil
>
>     On Thu, Sep 12, 2019 at 9:58 PM Tom McDermott via TangerineSDR
>     <tangerinesdr at lists.tapr.org <mailto:tangerinesdr at lists.tapr.org>>
>     wrote:
>
>         I've combed the meeting notes and some other thoughts and put
>         together a frist draft of possible DCC discussion topics for
>         HAMSCI / TangerineSDR.
>
>         Please review and send me additions, deletions, changes, etc.
>         by Monday the 16th and I'll iterate once before the conference.
>
>         -- Tom, N5EG
>
>         *HAMSCI project discussion Topics for DCC 2019*
>
>         1.    Need cost estimates for the Clock, DE, RF, and
>         Magnetometer modules.
>         2.    What is the schedule for the modules, testing, prototypes?
>            a.    Data Engine
>            b.    2-chan RF receiver
>            c.    GPS Clock
>            d.    Magnetometer
>            e.    Other ? SBC, Power supply, etc.
>         3.    Each module will have a unique manufacturer serial
>         number based on some PROMs that have this capability. Any
>         issues with the number or format?
>         4.    Do we need to create any videos describing what the
>         project is, what the objectives are, status, or other?
>         5.    No discussion so far on power supplies, other than a
>         request for +12V battery power capable. Do we need a plan?
>         6.    HAMSCI 2020
>            a.    Any more information on the location?
>            b.    Should we plan a demo of TangerineSDR or the
>         completed parts?
>         7.    Receive Antennas. Mike Pappas has acquired a calibrated
>         filed strength meter, we discussed seeing if DX Engineering
>         would let us measure a production lot of antennas (10?) to
>         determine the field strength sensitivity and variance.
>         8.    Do we need a test plan for the system?
>         9.    Upload data compression appears feasible (3:1 ?).  Do we
>         need any study or proposals of how much data we are asking
>         folks to upload? Or is this better to determine experimentally?
>
>         -- 
>         TangerineSDR mailing list
>         TangerineSDR at lists.tapr.org <mailto:TangerineSDR at lists.tapr.org>
>         http://lists.tapr.org/mailman/listinfo/tangerinesdr_lists.tapr.org
>
>
>     -- 
>
>     ----
>     Phil Erickson
>     phil.erickson at gmail.com <mailto:phil.erickson at gmail.com>
>
>

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