LIGO doesn't use discrete opamps. It must be for a good reason.
sorry to be pedantic, but
Not too many 8 legs in LIGO the most important thing was noise especially 1/f in the laser power. Once down to the thermal motion of the atoms at the surface of the mirror the improvement comes elsewhere.
I still have a part of the CD67 pcb(the one with hdam circuits) and they were identical with the much revered CD-63 , basically the whole cd 67 was identical with the cd63 except the power transformer...Unfortunately the laser was dead so i scraped it for parts count
Optical amplifier - Wikipedia
Also very high sensitivity transconductance amplifiers rely only on transistors in the first stage, but in a very tight thermally controlled environment, usually at very cold temperatures.
At some point we need different devices:
Optical transistor - Wikipedia
Last edited:
Someone linked to a very nice write-up on the instrumentation that I can't find where they put all the orders of magnitude in into perspective re the signal levels and they described how the mirrors were suspended on special 3 order gimbal mounts etc.
I guess the mirrors are cooled?
They were tight as hell - I think they prices were 2 or 3% off what you could get on the street.
The Japanese are working on cryo mirrors. The big change here, I think, is the squeezed light which I don't understand at all.
Yeah, I agree not necessarily so (hence my 'typically') and have seen such schematics in ADI's literature.
Of course, it is human nature. The cognitive literature is full of studies showing the effects of preexisting bias on accepting new information. People tend to accept results confirming their biases and preexisting beliefs, and reject results conflicting with their biases and preexisting beliefs. Interesting the reasons they can come up with to justify by argument a feeling that really comes from the gut (so to speak). Sometimes they will even say, "I know its wrong, but I don't know why."
Anyway, no wonder you have so much trouble trying to pin people down on what evidence they will accept. People intuitively know they may need some wiggle room later if a study turns out in way they don't feel comfortable with.
Here it is. SMD only, with thermal pad ---> not "socket compatible" with anything ---> invent your own idiosyncratic and incompatible pinout ---> no impact upon sales
_
Attachments
Thanks. It might just turn out to be worth all the incompatibility to experience that galactic level of PSRR goodness on the +ve rail. Wonder if I can find one locally.....
Ah, good news, someone's done all the donkey work for a pittance, I just need to figure out what they did with the 0V pin....
OPA1622 DIP8 ????? ??????-???
Attachments
Last edited:
Here's one https://dcc.ligo.org/public/0151/T1800133/004/T1800133-instrument-science-white-v4.pdf
See page 18
Squeezed light Squeezed states of light - Wikipedia
See page 18
Squeezed light Squeezed states of light - Wikipedia
Last edited:
Thanks. It might just turn out to be worth all the incompatibility to experience that galactic level of PSRR goodness on the +ve rail. Wonder if I can find one locally.....
Ah, good news, someone's done all the donkey work for a pittance, I just need to figure out what they did with the 0V pin....
OPA1622 DIP8 ????? ??????-???
Impressive. That's nearly 30dB better than an LM4562 at 20kHz on both rails.
Last edited:
It isn't? Do you have a proof of that?
I'm trying to dust up my memory, did you state that you are in audio business?
- Status
- Not open for further replies.