kids these days

What we know is that John Larkin wants us to think this.

The graduate he interviewed probably saw it differently.

Probably not. They are no less infested with John Larkin types than we are, and when these creeps get into powerful positions in the Chinese Communist Party they can be unpleasant to any number of people.

Ask the wrong question the wrong way and get answers that confirm your own prejudices.

This does rather ignore the point that Putin doesn't want peace - he wants a large piece of the Ukraine, and is working on getting it in a way that will intimidate all his other neighbours.

Peace envoys aren't fools - the only way to defuse the situation would be replace Putin with somebody less ambitious.

But then again, John Larkin thinks that he "designs" his electronics.

John mentioned a Vb of 0.6V so the 'student' is expected to know it's silicon. And of course, it's a Vbe of 0.6V and that distinction seems to trip up a lot of young folks, it seems. The Vb is 5. Once they get that straight, the rest of it falls into place easily enough. Should take < 30s for someone to figure out - and hopefully <<!

Indeed. But for those of us humans without shells, I'm assured hiding under a school desk is equally effective for any nuclear blasts up to

Yeah, the under 10s are all on Fentanyl and the teenagers have moved on to this stuff called 'duster' I gather. I'm told it's 20 times more addictive than crack cocaine and Wallmart sells it for $2 a can. Kids these days have it all. When I was young, street drugs didn't even exist.

Where's the Microcontroller Programmers Guide?

Joe Gwinn

So many people here prefer snarks to parts.

Probably few actually understand simple circuits.

"Paralysis by analysis."

No, I said that one EE grad claimed that Vb (not Vbe) would be 0.6 volts to ground.

Can anyone here say about what the base and emitter voltages actually are? Collector current?

Extra credit: anything else to say?

We tend to see this as a recent phenomenon, but it really isn't. Go back to Ireland a hundred years ago and you'd see 7 year-old boys running around smoking tobacco in clay pipes and it was not regarded as the least bit unsual!

Seriously? Vb is 5V. Vbe is 0.6V so Ve is 4.4V which gives us an Ie of

Standard ROT circuit from technician school BITD.

Beta of 200ish, roughly 4 mA I_C, so the base pulls 20 uA. With a 5k source, it’ll sag 100 mV, not much.

So V_E will be near 4.3 V, unless it oscillates, which it probably won’t unless it’s built on one of those nasty white nylon slab things.

(Technician school is particularly insistent on the distinction between beta and beta+1 in circuits, even though datasheet limits easily exceed

Cheers

Phil Hobbs

(who’s never taken a circuits course other than “RLCs for physicists”)

"john larkin" snipped-for-privacy@gct.com wrote in message news: snipped-for-privacy@4ax.com...

Why not ask about the essential features of the circuit below. Extra credit: What's it for?

Knowledge of things which were useful decades ago may not be so useful now.

How many students think that knowing how to design circuits like the one below will help them make money?

Version 4 SHEET 1 960 1280 WIRE -272 -144 -400 -144 WIRE 112 -144 -272 -144 WIRE 352 -144 112 -144 WIRE 544 -144 352 -144 WIRE -272 -96 -272 -144 WIRE 112 -96 112 -144 WIRE 352 -96 352 -144 WIRE 544 -16 544 -144 WIRE -272 16 -272 -32 WIRE 112 16 112 -16 WIRE 192 16 112 16 WIRE 352 32 352 -16 WIRE 480 32 352 32 WIRE 112 64 112 16 WIRE 192 112 192 80 WIRE 64 128 16 128 WIRE 112 192 112 160 WIRE 240 208 208 208 WIRE 544 208 544 80 WIRE 544 208 304 208 WIRE -400 256 -400 -144 WIRE 352 272 352 32 WIRE 16 304 16 128 WIRE 112 304 112 272 WIRE 112 304 16 304 WIRE 112 320 112 304 WIRE 208 320 208 208 WIRE 208 320 112 320 WIRE 288 320 208 320 WIRE 112 352 112 320 WIRE -288 400 -576 400 WIRE -240 400 -288 400 WIRE -224 400 -240 400 WIRE -128 400 -160 400 WIRE -16 400 -48 400 WIRE 48 400 -16 400 WIRE 352 400 352 368 WIRE 544 480 544 208 WIRE 592 480 544 480 WIRE 688 480 656 480 WIRE 832 480 768 480 WIRE 880 480 832 480 WIRE -16 496 -16 400 WIRE 16 496 -16 496 WIRE 112 496 112 448 WIRE 112 496 80 496 WIRE 112 512 112 496 WIRE 224 512 112 512 WIRE 352 512 352 480 WIRE 432 512 352 512 WIRE -240 528 -240 400 WIRE -16 528 -16 496 WIRE 112 528 112 512 WIRE 352 528 352 512 WIRE -576 608 -576 400 WIRE 832 608 832 480 WIRE -16 656 -16 608 WIRE 352 656 352 608 WIRE 352 656 -16 656 WIRE 544 672 544 480 WIRE 688 672 544 672 WIRE 112 688 112 608 WIRE 112 688 -16 688 WIRE 112 704 112 688 WIRE 352 704 352 656 WIRE 544 704 544 672 WIRE -16 720 -16 688 WIRE 432 720 432 512 WIRE 688 720 688 672 WIRE -576 832 -576 688 WIRE -400 832 -400 336 WIRE -400 832 -576 832 WIRE -240 832 -240 608 WIRE -240 832 -400 832 WIRE -16 832 -16 784 WIRE -16 832 -240 832 WIRE 112 832 112 784 WIRE 112 832 -16 832 WIRE 352 832 352 784 WIRE 352 832 112 832 WIRE 432 832 432 784 WIRE 432 832 352 832 WIRE 544 832 544 784 WIRE 544 832 432 832 WIRE 832 832 832 688 WIRE 832 832 544 832 WIRE -576 880 -576 832 WIRE 224 896 224 512 WIRE 256 896 224 896 WIRE 496 896 336 896 WIRE 544 896 496 896 WIRE 688 896 688 784 WIRE 688 896 624 896 WIRE 224 1024 224 896 WIRE 256 1024 224 1024 WIRE 368 1024 336 1024 WIRE 400 1024 368 1024 WIRE 496 1024 496 896 WIRE 496 1024 464 1024 WIRE 224 1136 224 1024 WIRE 256 1136 224 1136 WIRE 368 1136 368 1024 WIRE 368 1136 320 1136 FLAG -576 880 0 FLAG 192 112 0 FLAG -288 400 input FLAG -272 16 0 FLAG 832 480 output SYMBOL pjf 64 64 R0 WINDOW 0 -32 -1 Left 2 WINDOW 3 -87 35 Left 2 SYMATTR InstName J1 SYMATTR Value 2N4302 SYMBOL res 96 -112 R0 SYMATTR InstName R1 SYMATTR Value 150k SYMBOL voltage -400 240 R0 WINDOW 123 0 0 Left 0 WINDOW 39 -151 71 Left 2 WINDOW 3 -79 36 Left 2 SYMATTR SpiceLine Rser=0.1 SYMATTR Value 24 SYMATTR InstName V1 SYMBOL npn 48 352 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904 SYMBOL res 96 176 R0 SYMATTR InstName R2 SYMATTR Value 27k SYMBOL npn 480 -16 R0 SYMATTR InstName Q2 SYMATTR Value 2N3904 SYMBOL res 336 -112 R0 SYMATTR InstName R3 SYMATTR Value 22k SYMBOL npn 288 272 R0 SYMATTR InstName Q3 SYMATTR Value 2N3904 SYMBOL polcap 176 16 R0 SYMATTR InstName C2 SYMATTR Value 47µ SYMBOL res 96 512 R0 SYMATTR InstName R4 SYMATTR Value 470 SYMBOL res 96 688 R0 SYMATTR InstName R5 SYMATTR Value 39k SYMBOL res -32 512 R0 WINDOW 0 -41 40 Left 2 WINDOW 3 -63 76 Left 2 SYMATTR InstName R6 SYMATTR Value 270k SYMBOL cap 80 480 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 470p SYMBOL polcap -32 720 R0 SYMATTR InstName C3 SYMATTR Value 47µ SYMBOL res -32 384 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 1k SYMBOL polcap -160 384 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 1µ SYMBOL res -256 512 R0 WINDOW 0 40 38 Left 2 WINDOW 3 36 74 Left 2 SYMATTR InstName R8 SYMATTR Value 68k SYMBOL res 528 688 R0 SYMATTR InstName R9 SYMATTR Value 3k3 SYMBOL cap 304 192 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 10p SYMBOL res 336 512 R0 WINDOW 0 -52 35 Left 2 WINDOW 3 -58 72 Left 2 SYMATTR InstName R10 SYMATTR Value 5.6k SYMBOL res 336 688 R0 WINDOW 0 -53 28 Left 2 WINDOW 3 -47 61 Left 2 SYMATTR InstName R11 SYMATTR Value 10k SYMBOL res 336 384 R0 WINDOW 0 -59 36 Left 2 WINDOW 3 -61 76 Left 2 SYMATTR InstName R12 SYMATTR Value 2.2k SYMBOL res 352 880 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R13 SYMATTR Value 680k SYMBOL res 640 880 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R14 SYMATTR Value 1.5k SYMBOL res 352 1008 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R15 SYMATTR Value 24k SYMBOL cap 320 1120 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C6 SYMATTR Value 3.3n SYMBOL cap 464 1008 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C7 SYMATTR Value 10n SYMBOL polcap 672 720 R0 SYMATTR InstName C8 SYMATTR Value 1µ SYMBOL polcap 416 720 R0 SYMATTR InstName C9 SYMATTR Value 100µ SYMBOL polcap -288 -96 R0 SYMATTR InstName C10 SYMATTR Value 220µ SYMBOL polcap 592 496 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C11 SYMATTR Value 1µ SYMBOL res 784 464 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R16 SYMATTR Value 100 SYMBOL res 816 592 R0 SYMATTR InstName R17 SYMATTR Value 1000k SYMBOL voltage -576 592 R0 WINDOW 3 -283 51 Left 2 WINDOW 123 -283 79 Left 2 WINDOW 39 -283 107 Left 2 SYMATTR Value SINE(0 0.1 1000) SYMATTR Value2 AC 0.1 0 SYMATTR SpiceLine Rser=0 SYMATTR InstName V2 TEXT -864 808 Left 2 ;.ac oct 20 5 3000000 TEXT -416 1264 Left 2 !.MODEL 2N4302 njf VTO=-1.17 BETA=519u LAMBDA=7.72m CGD=2.30p CGS=2.30p PB=12.5 IS=14.9f MFG=InterFET TEXT -864 880 Left 2 !.tran 100m

You aren't interviewing many young EE grads!

Sure, people hang out in various parts of the abstraction stack, but real circuit design seems to be a fading art.

If they get the DC part about right, I ask them for any other comments. All sorts of things could be mentioned.

With the base looking at 5K, it's unlikley to oscillate. It would be a miracle if any kid even mentioned emitter follower oscillation. Or noise, or tempcos, or anything else.

R8 and C10 are interesting.

Think a resistor of 1K times hFE in parallel to the lower base divider resistor and recalculate for a better approximation. Or estimate Ib from Ie/hFE and use the Thevenin of the base resistors to correct the base drive voltage. Or use LTspice...

Arie

Looks like an audio pre-amp with RIAA equalization for a moving coil pickup.