Hi

I want to control a 115V motor with two windings (a ceiling fan motor) to
improve it's efficiency.

Normally, these windings are connected in series to the 230V AC mains with a
capacitor parallel to one of them (windings parallel for 115 V mains). I want
to control this motor with two full H-bridges and two PIC PWM outputs, so I can
match the frequency with the rotational speed. If I include a speed sensor too,
I can even optimise the frequency, voltage and phase angle to achieve maximum
motor efficiency.

Questions:

Are there dedicated IC's to do this? Most designs I saw used a standard DSP.

Where can I buy a 200V 2A full H-bridge that has TTL-compatible inputs?
Is it better or cheaper to buy half-bridges and level shifters?

Can anyone point me to a schematic with a reasonable low component count?

Is there some source for a PWM-output sine function lookup table?

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Ir. E.E. van Andel, Fine Wire Heat Exchanger Technology  www.fiwihex.com
Wierdensestraat 74, NL-7604 BK  Almelo, The Netherlands   eur@fiwihex.nl
phone +31-546-491106  fax +31-546-491107  mobile +31-653-286573

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