To good to be true?

[Ouroboros]

I'm not saying my regulator is the same. It's just a simple two-transistor LDO that works well. (Just as a comparison)

[Elso Kwak]

Hi, I can imagine two possibilities:
1. Darlington connected,
2. Sziklai (complementary Darlington).
Both with a reference or zener at the base. To call the Sziklai positive feedback I am not sure.....

[jan.didden]

Originally posted by slowhands
I am always skeptical of radical claims in this field.

Bongiorno is a genius, technically and as a huckster. I fear this one is more marketing blarney than technical breakthrough.

Also note that he puts "positive" between quotes. I wouldn't hold my breath for that breakthrough.

Jan Didden

[Steven]

I have no idea how it works, but a combined positive and negative regulator looks like the right hand side of this photo. Just not big enough to see the details.

Steven

[boholm]

Does this qualify for a two transistor PSU?



P.S.: Don't get too hooked on the values. This was just a test to see if it could work - and it can.

[Ouroboros]

Yes, but it really needs a zener to provide a reference voltage in series with the emitter lead of the lower transistor.

[lumanauw]

Hi, Steven,

I like this very much.

The Analog Art shows no sign of yielding to the Dodo's fate. The emergence and maturation of monolithic processing finesse has perhaps lagged a bit behind the growth of the Binary Business. But whereas digital precision is forever bounded by bits, there is no limit excepting Universal Hiss to the ultimate accuracy and functional variety of simple analog circuits. - Barry Gilbert, 1973

I also think analog is kind of "Art" while digitals are "Exact science"

[jan.didden]

Originally posted by lumanauw
Hi, Steven,

I like this very much.

I also think analog is kind of "Art" while digitals are "Exact science"

The way I see it, successfull design, whether analog or digital, is the art of optimum choice in trade-offs and compromises. It's all art in the end.

Jan Didden

[djk]

"Yes, but it really needs a zener to provide a reference voltage in series with the emitter lead of the lower transistor."

Why?

NAD use this type of regulator without a zener.

[Ouroboros]

Originally posted by djk
"Yes, but it really needs a zener to provide a reference voltage in series with the emitter lead of the lower transistor."

Why?

NAD use this type of regulator without a zener.

Sure it'll work as a bodge job, but the temperature stability of the output is atrocious if you only use the Vbe of the sense transistor as the voltage reference. (just Spice it and look at the temperature plots)