Re: 556 sstc idea

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <MShock8073-at-aol-dot-com>

In a message dated 2/10/02 12:50:01 PM Eastern Standard Time, tesla-at-pupman-dot-com
writes: 


>
> Since a 556 is a dual osccilator, is it possible to sync it right so it would
>
> turn on one mosfet while the other is off?And then it would go off and the 
> second would turn on? 
>
> How hard would this be?Is it possible? 



Matt, 
There is an article in the August 1997 issue of Electronics Now where they use
a very similar circuit to drive a custom rewound bifilar primary winding on a
B&W flyback to run a "poor-man's plasma globe" which is the name of the
article. The circuit runs 2 IRF540 MOSFETs to drive the bifilar windings and
the chip used is called a regulating pulse width modulator. It is an SG3525A
and has 2 outputs that are 180 degrees apart. This chip, in a plastic, as
opposed to ceramic package, is available as an NTE1721 (I think). The NTE (ECG)
parts are kind of pricey, over 5 bucks at the almost out of business
RadioShack-dot-com store here in Atlanta, but the generic parts were available for
less than a dollar each from Mouser last time I checked. Being a PWM chip, you
can vary the off time of each output and the core frequency. This may not be
exactly what you wanted, but it would be an easy place to start. 

Marc S.