[sdiy] 12VDC to 12VAC converter [OT]

[Seb Francis]

ASSI wrote:
> On Montag 03 September 2007, Seb Francis wrote:
>   
>> I need to produce a 12VAC 20VA 50Hz supply from a 12VDC input.  It's
>> to run a 12VAC motor from a car battery, so the AC voltage doesn't
>> have to be particularly sine-like or regulated.
>>     
>
> Look for a PWM driver for appliance motors, preferrably with an 
> integrated H-bridge and just feed it an unmodulated 50Hz (or whatever 
> is close enough) signal.  Rolling your own is entirely possible at 
> roughly 2A, but then you have to deal by yourself with controlling the 
> dead-time during the switching event and with the reactance from the 
> motor coils.  If you do roll your own controllers, there are ready-made 
> H-bridge or half-bridge IC, both bipolar or MOSFET and with or without 
> the driver circuitry from many companies.  Just the bridge drivers are 
> available seperately, too.  There's a stub entry on Whackypedia that 
> has a few external links that may be helpful:
>
> http://en.wikipedia.org/wiki/H-bridge
>
> Google brings a lot of useful links on that topic as well.
>
>   

Ah that makes a lot of sense .. it's still going to be a square wave 
(not sine) fed to the motor, but it will be effectively 24V peak to peak 
which (being a square wave) should be equivalent to 12VAC RMS.

Looks like it would be a nice simple circuit too.  Thanks!

Seb