Cascode emitter follower

...naturally, one counts capacitors, inductors, resistors, FETs, tubes, transformers, etc.

The only good that has come from them, is the royalties to the inventor.

Of course no white board! Does the copper clad and connectors count as parts?

George H.

Does the 24 include mixing bipolar with fets?

George H.

I meant a total of 7 parts. Everybody gets a sandwich-sized ziploc with the 7 parts inside. Maybe they furnish their own battery.

Why so many parts? One microcontroller with integrated everything, some decoupling...

Cheers

OK then, design us a >100MHz bandwidth,

Actually with a microcontroller running spice, I possibly could _design_ such a thing :-)

Cheers

The objective would be to teach them about electronics - you know, controlling electricity - not how to type some artificial, arbitrary language.

It's absurd how technology is now mostly identified with coding. The giant software companies, aided by paid politicians, want to teach every schoolkid to code. I teach a few kids how to think about and design electronics. I bet my kids do better.

Sure, my guys can code too; anybody can do that.

Dunno. We should see how many we can find. This is what I came up with in ten minutes or so:

1. Darlington
2. Sziklai and other shunt feedback things
3. Cascode
4. Follower with tail current source
5. Collector/drain bootstrap
6. diff pair
7. Cascaded common-emitter stages
8. Common base plus follower
9. Common emitter plus follower
10. Cascaded followers
11. Series connection for higher voltage
12. Parallel connection for higher current
13. Push-pull follower (class B)
14. Push-push doubler
15. Muting switch plus follower
16. Current mirror
17. SCR connection
18. Royer converter
19. Log converter with follower for temperature compensation
20. Two-terminal current limiter

And then maybe some variations:

a. Series-shunt pair b. Schmitt trigger c. Eccles-Jordan flip flop d. White-style follower e. Exponential current source f. PNP level shifter (grounded base) plus follower g. .....

So what did I miss, everybody?

Cheers

Phil Hobbs

...

...

I'd kinda call the 'cascaded followers' a dupe of Darlington. Not sure what a push-push doubler is,,,

This pairing doesn't come up often (but it'd handle sine-to-square converter needs, input capacitor coupled). Don't know how to name it.

| ---+--\ | | V | \ | +--- | ----+--R--+ | | GND (+)bias

The difference is that the two collectors needn't be connected together. One can argue about that, I suppose. A replacement might be

1. Phase splitter plus follower. That gives +/- phases with about the same drive impedance and reduces phase funnies.

A push-push doubler has the bases driven in phase and the collector currents in push-pull (i.e. subtracted using a centre-tapped transformer). The symmetry ideally gets rid of the fundamental and odd harmonics.

Cute. That's sort of the push-push circuit, but run sideways and used like a diode clipper.

Cheers

Phil Hobbs

That can be done all-NPN... I did this...

for a smog controller chip at Philco-Ford, Santa Clara, in 1968 ...Jim Thompson

Two transistors, remember!

Cheers

Phil Hobbs

Just remove Q3, but you won't get a flat baseline. ...Jim Thompson

Now you got me curious. What did that go in ? Were there ECMs in cars in California back then ? I know electronic ignitions existed, and i fact had for about ten years, but were not in common use.

Den torsdag den 21. juli 2016 kl. 18.00.45 UTC+2 skrev John Larkin:

anybody can use a hammer and saw, that doesn't mean you'd want just anybody to build you a house

-Lasse

Well You are going to be much better at that game than me. (most of the time I need an opamp to help me with my transistor circuits. :^)

OK, I'm printing that out and I'll try and draw what I think you mean, (it will be a few days... I've got a workshop thing to run.)

George H.

I'd add

same drive impedance and reduces phase funnies.

1. Two-stage cap multiplier (a fave)

g. NPN/PNP emitter follower to more-or-less get rid of the offset. (Cascaded followers really want to oscillate, though.)

Cheers

Phil Hobbs