[volt-nuts] fluke 731b battery pack

[David]

On Wed, 3 Aug 2016 14:30:33 -0700, you wrote:

>On Wed, Aug 3, 2016 at 2:08 PM, David <davidwhess at gmail.com> wrote:
>
>>
>> I looked at the schematic and is seems feasible without excessive
>> effort.  Either the existing simple series preregulator can be
>> modified or replaced allowing it to both charge the battery (through a
>> blocking diode) and power the instrument or a completely separate
>> power charging circuit can be added in parallel.
>
>The existing charging circuit _is_ in parallel with the pre-regulator; they
>are separated by CR5 and CR6 and the pre-regulator/battery outputs are
>combined by CR8 and CR9.  The only problem with the existing circuit is
>with a fresh, strong, fully charged battery pack, charging pulses will leak
>past CR8 with only R1/C1 to filter them.

Ah, I did not see that A1S1A is the same as switch A1S1B; I am used to
seeing a little dashed line connecting all of the elements of a single
switch.  I guess that goes along with the symbol they used for
constant current diode CR10 which I have not seen in a long time.

Anyway, the changes I suggested still apply.  Actually, using a
battery which accepts a constant voltage charge simplifies the
requirements.