>
>
> A
> useful part when you are forced by marketing to use 4 cells on a 5 volt
> project ;-)
>

One such got me a (paid) trip to Taiwan (about 2001 I think).
Taiwanese designed cct was causing problems in equipment made for client.
They offered no solution (strangely).

4 x C cells. Exercise equipment.
DC motor drive to move magnetic drag plate.
5V and 3V rails !!!!

SMPS - I used a 74C14 :-) driving a transistor + an LDO.
LDO had a transistor connected with base-emitter across it via resistor -
this was used to control SMPS so held LDO with ~=3D 0.6V headroom.
Worked very well. [74C14 worked in a phase modulated mode. AFAIR I started
expecting it to work in a fairly sharp on/off regulating mode but end
result had very nice sliding mark-space to suit.

Taiwanese factory engineer would not initially believe it would do what was
required.
He got out a LARGE box of variably dead C cells and tried many.
My cct worked happily with all. Motor drive got vvv slow on fully dead (sub
1V loaded) cells but 5V and 3V rails were maintained.
What fun.


        Russell
--=20
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