> The circuit described in my OP is intended to run on 4 x "AAA" cells. It'=
s
> function is to produce a low intensity, rotational magnetic field via a
> circular array of 6 reed relay coils (500-1K Ohms). Two coils would be
> energized at a time (opposite positions) so a 120 degree phase difference
> is required between each of the three sinewaves. Required output to each
> coil is less than 50ma.

I read that as saying that the coils are activated or deactivated -
that you are activating reed relays when a sine wave signal reaches a
certain amplitude and deactivating it at some other level. (Possibly
the same level but falling amplitude)..

But, if I understand it correctly, NO external sine wave is required -
it need exist only conceptually in the mind of the machine with reeds
being on/off activated as required at the correct times as the
internal software vector rotates.

If my understanding is correct then the hardware design is super
simplified. NO visible sine waves, DACS, ADC's PWM, filters etc.  Just
connections to reed coils.

Am I misunderstanding this?


            Russell

>
> Passively filtering PWM outputs is acceptable since only a approximate
> sinewaves are required. IOW I don't want a discontinuous stepping motor
> type effect. Cost and parts count to be minimal, eg. PIC, LPF passives an=
d
> 3 op amps. Frequency is fixed at around 8Hz and must be stable to 0.1 Hz.
>
> Given this additional information, requested by a few correspondents, any
> further suggestions would be much appreciated. For example, which PIC to
> use, how many LUT's are actually required, and advice regarding the code.
> If I feel the programming is beyond my own current level of expertise, I
> may approach those members who have expressed interest in doing the work
> for a fee.
>
> Peter Nielsen
>
>
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