resetting a filter

One of the only true things I've ever seen you state.

The boards that drove them were, IDIOT! They had TTL front ends at the very least.

It wasn't true, because I meant RJ45. You're wrong even when you're agreeing with me.

--

John Larkin Highland Technology Inc

Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators

Yes, he most certainly IS stupid.

They still do.

While collisions are not usually a problem, they still occur all the time.

A false proposition which you'd haven't advanced a shred of evidence to support.

It certainly wasn't a big deal. He was making money out of going around addressing meetings about Ethernet, and my employers sent me along to one of them. I got to talk to him after the meeting - he was too busy being charismatic to say anything useful.

Which worked, but not all that well, and didn't exactly take over the world.

ds on

Wow. I had to settled for telling our managing director what might work - Ethernet - and what wasn't going to last - Arcnet, amongst others. This was in the UK, where the Cambridge Ring had some adherents.

I got to meet Roger Needham years later, and wasn't impressed. His wife - Karen Spark-Jones -

was well worth talking to.

I never did meet Andy Hopper, who went on to help develop the ARM processor amongst many other interesting bits of work.

I was never taught much electronics, but I learned a great deal about the subject by reading useful books and papers.

You have been posting deluded nonsense here for years, so it isn't exactly surprising that you can't recognise my odd areas of competence, restricted though they may be.

-- Bill Sloman, Nijmegen

On Mon, 13 Aug 2012 15:12:28 -0700, John Larkin wrote:

--- Geez, I guess you missed my contribution to the 555 thread (the one where I posted a link to Hans Camenzind's schematic) and my high side and low side current sources over on seb.

I've spruced them up a little so, FYI, here they are:

Version 4 SHEET 1 952 680 WIRE -112 16 -848 16 WIRE 192 16 96 16 WIRE 336 16 192 16 WIRE 464 16 336 16 WIRE 720 16 464 16 WIRE 192 48 192 16 WIRE 336 48 336 16 WIRE 720 48 720 16 WIRE -112 64 -112 16 WIRE -848 96 -848 16 WIRE -768 96 -848 96 WIRE -624 96 -688 96 WIRE -528 96 -624 96 WIRE -384 96 -528 96 WIRE -528 128 -528 96 WIRE 720 160 720 128 WIRE 720 160 400 160 WIRE -112 192 -112 144 WIRE 720 192 720 160 WIRE -384 208 -384 96 WIRE 464 208 464 16 WIRE -416 224 -448 224 WIRE 400 224 400 160 WIRE 432 224 400 224 WIRE -176 240 -352 240 WIRE 656 240 496 240 WIRE -528 256 -528 208 WIRE -416 256 -528 256 WIRE 192 256 192 128 WIRE 224 256 192 256 WIRE 336 256 336 128 WIRE 336 256 304 256 WIRE 432 256 336 256 WIRE -448 320 -448 224 WIRE -112 320 -112 288 WIRE -112 320 -448 320 WIRE 192 320 192 256 WIRE 464 320 464 272 WIRE 464 320 192 320 WIRE -848 352 -848 96 WIRE -624 352 -624 96 WIRE -528 352 -528 256 WIRE -112 352 -112 320 WIRE 96 352 96 16 WIRE 720 352 720 288 WIRE 192 384 192 320 WIRE -848 480 -848 432 WIRE -624 480 -624 416 WIRE -624 480 -848 480 WIRE -528 480 -528 432 WIRE -528 480 -624 480 WIRE -384 480 -384 272 WIRE -384 480 -528 480 WIRE -112 480 -112 432 WIRE -112 480 -384 480 WIRE 96 480 96 432 WIRE 192 480 192 448 WIRE 192 480 96 480 WIRE 720 480 720 432 WIRE 720 480 192 480 WIRE -848 560 -848 480 WIRE 96 560 96 480 FLAG -848 560 0 FLAG 96 560 0 SYMBOL res -128 48 R0 SYMATTR InstName R1 SYMATTR Value 240k SYMBOL npn -176 192 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res -128 336 R0 SYMATTR InstName R2 SYMATTR Value 20k SYMBOL Opamps\\LT1001 -384 176 R0 SYMATTR InstName U1 SYMBOL res -544 112 R0 SYMATTR InstName R3 SYMATTR Value 28k SYMBOL res -544 336 R0 SYMATTR InstName R4 SYMATTR Value 20k SYMBOL voltage -848 336 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V1 SYMATTR Value 70 SYMBOL res 704 336 R0 SYMATTR InstName R6 SYMATTR Value 240k SYMBOL res 704 32 R0 SYMATTR InstName R7 SYMATTR Value 20k SYMBOL Opamps\\LT1001 464 176 R0 WINDOW 0 -87 97 Left 2 WINDOW 3 -89 122 Left 2 SYMATTR InstName U2 SYMBOL voltage 96 336 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 70 SYMBOL pnp 656 288 M180 SYMATTR InstName Q2 SYMATTR Value 2N3906 SYMBOL zener 208 448 R180 WINDOW 0 -38 33 Left 2 WINDOW 3 -88 -3 Left 2 SYMATTR InstName D1 SYMATTR Value 1N5371B SYMBOL res 176 32 R0 WINDOW 3 36 68 Left 2 SYMATTR Value 1000 SYMATTR InstName R8 SYMBOL res 208 272 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R9 SYMATTR Value 10k SYMBOL res 320 32 R0 SYMATTR InstName R11 SYMATTR Value 10k SYMBOL res -672 80 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R12 SYMATTR Value 10k SYMBOL zener -608 416 R180 WINDOW 0 54 33 Left 2 WINDOW 3 31 -3 Left 2 SYMATTR InstName D2 SYMATTR Value BZX84C12L TEXT -824 512 Left 2 !.tran .01 startup uic

-- JF

From AlwaysWrong, that's a compliment. It would be a bigger compliment if there was any evidence that he ever knew what he was talking about.

All that "stupid" means in this context is that I've disagreed with him, which is pretty much inevitable and universal, since he is AlwaysWrong.

-- Bill Sloman, Nijmegen

That's all they had, The drivers ran at 9V

Base resistors would help. The transistors will want to oscillate at

Maybe. I presume the output is at the collectors, so the emitter nodes should be low capacitance, so not a likely "sing". The only way to know for sure is to run loop gain and phase. You ran that before you commented, didn't you John Larkin?

Adding said "base resistors" might actually aggravate the phase and _cause_ oscillation.

There was a post here much earlier this year...

From: Bob Engelhardt Newsgroups: sci.electronics.basics Subject: A couple of simple questions about a simple op amp circuit Date: Sun, 01 Apr 2012 11:34:26 -0400 Organization: NewsGuy - Unlimited Usenet $19.95 Lines: 16 Message-ID:

that shows the proper way to _guarantee_ stability independent of loop or load. ...Jim Thompson

Show some official schematics. ...Jim Thompson

-- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at

What an idiot. How is "loop gain and phase" going to matter when the opamp GBW is 800 KHz, and the transistor oscillates at 100 MHz?

It's not a loop oscillation hazard, you senile moron. The opamp is involved, but you don't know why. Why can't you leave me killfiled?

It doth seem that it is you, John Larkin, that is the senile moron. Go back and re-read what you posted.

(Actually, John Larkin is a _manic-depressive_ moron... with a heavy dose of MORON.)

Killfile you? I only killfile your Slowman-related rants... I so much enjoy watching you post idiotic circuits. You've gone round-and-round on this "delay", aka "resetting a filter", aka "fast ramp follies". Why haven't you got it right already ?:-) ...Jim Thompson

Both circuits, in two quite different products, are right. I've got two other, different, fast current sources in recent designs, one closed-loop and one bootstrap. You bragged about having something good, but as usual is was an empty boast.

You really don't understand why JFs circuit might oscillate. You actually think an 800 KHz opamp will participate in a 100 MHz loop oscillation. Explain that "loop gain and phase" to us.

You're so eager to be an asshole that you quit thinking.

As usual, nothing substantive, just invective. ...Jim Thompson

page 25

-Lasse

I post actual circuits for discussion, fairly often. JF posted a working circuit that I commented on. You have said nothing substantive, just senile whining. You haven't explained your comment about "loop gain and phase", namely how an 800 KHz opamp can participate in a 100 MHz oscillation. So be substantive and explain it.

You don't understand this stuff. You can't manage a killfile, either.