Re: Off Line - DRSSTC (OL-DRSSTC) - 3

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi DC,

With 440uF and 5mH and 120VAC in I am getting 262 VDC firing voltage.

http://hot-streamer.com/temp/OL-DRSSTC-04a.gif

The AC voltage is in blue and the cap voltage is in red in the chart.

Cheers,

        Terry


At 07:03 AM 9/29/2005, you wrote:

> What is the DC output of the resonant charger with the values you 
> have for design# 3?   5 mH & 440 uF?
>
>
> Dr. Resonance
>
> > I have dropped the voltage and played with power so 40  22uF 200V 
> > caps will now work.  The caps completely charge and discharge 60 
> > times a second so the ripple current is rather enormous!
> >
> >
> > > Have you some up with any general design for the primary, sec, and 
> > > topload requirements?  I was thinking of an 8 inch dia. PVC 
> > > coilform, 14 x 5 load, 2,500 turns on the sec coil, aspect ratio of 5.5:1.
> >
> > Any coil should work that is say 150kHz or less.  The primary cap 
> > and all needs to be made so the peak primary current is within the 
> > range of the IGBTs.
> > > This is an exciting concept and I look forward to building one asap.
> >
> > Ok, but it has never been done so no guarantees ;-)  The circuit 
> > design changes all the time.
> >
> > Cheers,
> >
> >         Terry
> >
> >
> >
> > > Dr. Resonance
> > >
> > >
> > > > Hi All,
> > > >
> > > > I have been running a lot of models and now have this for the OL 
> > > > -DRSSTC concept schematic:
> > > >
> > > > http://hot-streamer.com/temp/OL-DRSSTC-03.gif
> > > >
> > > > I had to go to 60BPS instead of 120 BPS.  I use the dead 1/2 
> > > > cycle to fire the coil so there is no incoming current to quickly 
> > > > recharge the buss cap. Otherwise, once the coil is started, in 
> > > > never turns off!!  The waveforms look like this:
> > > >
> > > > http://hot-streamer.com/temp/OL-DRSSTC-03a.gif
> > > >
> > > > It should put out nice 60BPS bursts with 200kV peaks.  Very long 
> > > > 2mS duration.  Power to the streamer is roughly 1080 watts.  The 
> > > > resonant charger gets the cap up to about 520VDC firing voltage 
> > > > with the line and resistive losses (note that the inductor is 
> > > > 19mH now for 60Hz).  It is a stunning 25 joules per bang!!!
> > > >
> > > > The primary current is only 200 amps and everything else seems 
> > > > generally easy without massive over loads.  The 50 ohm resistors 
> > > > across the gates reduce the gate voltage and act a bit like a 
> > > > dead zone for the IGBT crossover.
> > > >
> > > > The trigger circuit is pretty much out of the SIDAC data sheet...
> > > >
> > > > The only concern is the 185uF buss cap.  It will see about 22A 
> > > > RMS!  That would kill most single electrolytics so I will have to 
> > > > look into that more.
> > > >
> > > > By changing the SIDAC value, it should work off 120VAC or a 
> > > > variac at lower test  voltages too.  Everything can be "fiddled 
> > > > with" as needed to make adjustments or to get it to work.
> > > >
> > > > So it is looking pretty good on paper and by computer.  I think I 
> > > > will order some parts...
> > > >
> > > > Cheers,
> > > >
> > > > Terry