purpose of TL081 in this circuit? - LowRippleHVsupply2.jpg (0/1)

A simulation shows capacitance multiplication has died by 200KHz, and there's a big slug at 11KHz as you predicted.

Not a very well thought out circuit... probably pasted together without analysis.

...Jim Thompson

A faster opamp would only push this up modestly, by sqrt f_T.

But it is an excellent "ripple stripper" below ~ 150kHz, able to handle several volts of ripple into the 10k R-C filter (the level is of course greatly attenuated by the time the opamp sees it). We really can't completely badmouth it, after all Charlie Thompson (any relation?) didn't claim it was a "capacitance multiplier."

No relation that I know of, but ALL Thompsons are probably related... we came over on the first boat to Jamestown ;-)

Someone mentioned floating the ground to do ripple reduction... seemed an interesting concept to me.

...Jim Thompson

I thought it was the liberal weenies who love to throw taxpayer dollars at everybody and their uncle.

There's a difference between merely _not banning_ a certain form of research based on religious dogma, versus actually _spending taxpayer money_ on it.

_Allow_ it, yes. _Fund_ it with money stolen out of your hard- earned paycheck, NO!.

Thanks, Rich

Bush is pretty good at throwing piles of dollars where he pleases.

Now that we've established we can do the research in MA, we're considering funding some of the work. Why? It's our money, to use as we in society see fit. We want the research results, and we want to keep as much of this biotech work here as we can. In the past the state has done well on tax income from our reams of successful biotech companies and their employees, so planting some seed funding may actually pay off financially in the end. But we do badly want the medical results as well, and we don't want to have to pay the big bucks to get them from South Korea, either.