Maintaining a Vbe Multiplier's bias value

he vast

=A0-

Thanks Phil I'll try google. Why are there still so many tube amps? You'd think someone could make a solid state amp that sounded 'right'.

George H.

A very comprehensive book, bible lets say is The Crcuits and Filters Handbook by Chen don't get fooled by "Handbook", it's the biggest book I got. :-)) ciao Ban

A lot of transistor amps sound right, but some people prefer to add a bit of

or the reference input. But some power diode antiparallel will take care of that. ciao Ban

Just to be clear, with B+ at the center-tap.

Jon

Cripes. If you walked into the house you'd see walls of polished bookshelves from floor to ceiling covering every spare bit of wall space in my library off the mail hall. I'm already overflowing out of there into another room and my wife isn't exactly happy about it. But what's another book or two? ;) I'll add it to my next order from somewhere.

Jon

The fish/fish rule ?:-) ...Jim Thompson

Close, but no cigar, LM395 = LM317 with some metal rearrangements.

I did this analysis for ICE back in 1980:

Additionally: Amusing myself with the thoughts of complementary- follower-style power amplifiers made from LM317/LM337 pairs, it fails because both, internally, are NPN's pass devices, so the LM337 has GBW and stability issues plus it needs substantial idle load to stay _vaguely_ stable. ...Jim Thompson

What? For playing your favorite atonal pieces by Schoenberg, Berg, Stravinsky, or Webern ?:-)

Back in college, 4 semesters of classical music provided me with "easy A electives", but my wife would come unglued after just a few minutes of those guys ;-) ...Jim Thompson

Build a man a fire, you keep him warm for a night. Set a man afire, you keep him warm for the rest of his life. ;)

Cheers

Phil Hobbs

"fast"

I was thinking 317 but then I decided that the 395 was older than that. I guess not.

Non-LDO three-terminal regulators are so trouble-free that it's easy to confuse them with Newton's laws. ;)

Cheers

Phil Hobbs

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Ahh OK a transformer 'sums' the signals.

Thanks,

George h.

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=A0 =A0 ...Jim Thompson

=A0 =A0| =A0 =A0mens =A0 =A0 |

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=A0|

=A0 =A0 =A0 |

ide quoted text -

Thanks Jim, I always wondered why there wasn't a compliment to the LM395. (And why the negative voltage regulators would 'wig out' if you didn't follow the cap reccomendations.)

George H.

"fast"

LM1117 is an "MDO" regulator. It has an NPN pass transistor but a bit lower dropout voltage than an LM317. Its ideal as a 3.3-to-1.25 volt FPGA core voltage source... no resistors! My purchasing notes say "Do not buy Fairchild per JL" but I can't recall why.

As with all vregs, one has to be careful about the output capacitors.

John

Got snow?

John

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=A0 =A0 =A0...Jim Thompson

ted text -

"> Build a man a fire, you keep him warm for a night. Set a man afire, you

Can't help being reminded of "The Cremation of Sam McGee".

And there sat Sam, looking cool and calm, in the heart of the furnace roar; And he wore a smile you could see a mile, and he said: "Please close that door. It's fine in here, but I greatly fear you'll let in the cold and storm =97 Since I left Plumtree, down in Tennessee, it's the first time I've been warm."

Taken from here, "

George h.

I'm puzzled why the big semiconductor houses don't turn out discrete LDO's on a CMOS process. I do it all the time on complex CMOS ASIC's... like a PLL chip, fundamental power fed from +3.3V, but internal regulators producing +2.5V and +1.8V... at hundreds of mA !!! ...Jim Thompson

Almost. It's more like: I'd like to get to Fresno Flats (aka Oakhurst, near Yosemite) from Portland, but rather than just fly there (okay, so I have to parachute out) I'd like to enjoy the trip this time, too, and detour around a bit to some of the sights along the way.

First off, maybe to the Opal Creek Wilderness area to see some of the 800 year old cedar groves; then maybe south to a short visit at White's Electronics in Sweet Home; then to Crater Lake; maybe then to Oregon Caves; off perhaps to do some panning for gold in Jackson County while also taking a hike in the Siskiyous; then on over to hwy 101 at Brookings to do some whale watching; down to Crescent City to visit the Jedediah Smith and Del Norte parks and see what's left of the redwoods there; ....

Well, might as well make a thing of it this time 'round. Oakhurst won't go away while I'm on the road.

Jon

earlier.

"fast"

quoted text -

There are lots of positive LDOs around these days that have PNP (namely high impedance) outputs. They tend to be very picky about output capacitance ESR and such, with appropriately evasive datasheets. I had one powering an FPGA core, putting a 0.2 volt p-p,

John