John Curl's Blowtorch preamplifier part II

[31697B]

Dick thought about it some more, a Quinn cas-comp input and the 797 second stage would make an interesting amp.

😎🙂😀

Scott; Would you show us how, exactly?
Maybe over at the forum/thread where you put up your line level amp circuit? or?


Thank you,
Dick Marsh

 

[Bonsai]

I had no say so don't know. I brought a very servicable automotive audio power amp from ST into the packaging dept as an example and they said simply, "We don't deal with those vendors". They would have been refering to package sub cons in that case, yes.

Well, that figures on two counts.

😉

 

[scott wurcer]

😎🙂😀

Scott; Would you show us how, exactly?
Maybe over at the forum/thread where you put up your line level amp circuit? or?
Thank you,
Dick Marsh

I'll see if I can sketch something out in LTSPICE, which means I have to do it at home.

 

[scott wurcer]

I'll see if I can sketch something out in LTSPICE, which means I have to do it at home.

Not looking good, too many parts to get it all in as well as not having the ability to area ratio discrete devices.

 

[31697B]

🙁😕

 

[john curl]

Recently this article appeared in an IEEE publication. It closely parallels my experience at Cory hall 1.5 years later. I attribute this part of my education to be most important to be a successful designer.

 

[jneutron]

Recently this article appeared in an IEEE publication. It closely parallels my experience at Cory hall 1.5 years later. I attribute this part of my education to be most important to be a successful designer.

Interesting picture. Brings back memories of a metallurgical scope.

Why are there two uncommitted NPN's and one uncommitted PNP on the die? Were they ever bonded to the outside world?

jn

 

[scott wurcer]

Interesting picture. Brings back memories of a metallurgical scope.

Why are there two uncommitted NPN's and one uncommitted PNP on the die? Were they ever bonded to the outside world?

jn

Test drop-ins probably. BTW the guy from CERN gave a great talk on finding the Higgs bozon at ISSCC they say.

 

[john curl]

That's interesting Scott. How would that subject come up at ISSCC?

 

[scott wurcer]

That's interesting Scott. How would that subject come up at ISSCC?

Invited keynote on instrumentation and computing in the big science community.

 

[jneutron]

Test drop-ins probably. BTW the guy from CERN gave a great talk on finding the Higgs bozon at ISSCC they say.

They were here as well, back about the time they made the announcement. He played to a packed house.

I suspect the talk here was a tad more physics oriented though. Go figure.

jn

 

[ticknpop]

a friend designed the high voltage / high current extremely tight voltage regulation rectfiers used to control the coils at CERN . When rectifiers are the size of 2 door fridges they become interesting.....

 

[jneutron]

Here's a better analysis of the chip.

I see that the schematic is missing some ties.

Q7 emitter ties to the 1.5k and Q8 base.
Q3/6 ties to pad 3
Q10 C/B s/b tied
Q11 C/B should be tied.

Ah, the old days..

edit: oops, forgot the 4 ohm resistor..it is physically between pad 1 and 6..

jn

 

[jneutron]

a friend designed the high voltage / high current extremely tight voltage regulation rectfiers used to control the coils at CERN . When rectifiers are the size of 2 door fridges they become interesting.....

Ah, air cooled compression hockey pucks, my guess would be 100 mm diode wafers.

Bah, room temp diodes, anybody can do those...😉

jn

 

[ticknpop]

actually the CERN rectifiers are water cooled and the size of walk in freezers.
(I didn't want to scare the timid.....)

 

[a.wayne]

Halo JC-1's in the house ...........

 

[jneutron]

actually the CERN rectifiers are water cooled and the size of walk in freezers.
(I didn't want to scare the timid.....)

Ah, interesting. we stuck to air because of the DI water issues.

jn

 

[ticknpop]

DI?

I build power supplies too, but not so big - 100 to 700 amps@120 VDC fan cooled switchmode - for charging lithium ion batteries these days with 300mv ripple at 500 amps.

 

[jneutron]

DI?

I build power supplies too, but not so big - 100 to 700 amps@120 VDC fan cooled switchmode - for charging lithium ion batteries these days with 300mv ripple at 500 amps.

Deionized water. Non conductive.

If the system isn't too big, air is simpler. DI requires more infrastructure, so can get expensive.

jn

 

[31697B]

Would you cite an example ?

Sorry for the slow reply -- Quick attempt with limited supply of devices... not supposed to be compliments but are close (TO18 and TO39).

Thx-RNMarsh