Circuits under pressure

Il 29/10/2010 10:00, Rich Grise ha scritto:

Not more than 250 bar = 3,600 psi

Marco

3

For tubes, the first number indicated a power rating. For semiconductors, the first number was the number of leads/contacts minus one.

Optocouplers have 2 leads on the input side, and 3 leads on the output side (if they bring the base from the phototransistor out... I know sometimes they didn't bring it out and they still lumped it under 4N.)

5 leads minus 1, gives a 4. At least that's what I always figured :-)

Tim.

2500 metres immersion (water)?

Marco Trapanese:

Below 1000 meters depth the temperature is around 4 C.

who where:

I believe it's reason why he posed this question.

At that depth his ROV cannot be watertight as his current ones.

Tim Shoppa:

Humm. I'm not convinced.

Do you know of any FET, MOSFET, unijunction or triac with this style of numbering?

The 6N optocouplers have 2 (LED) plus 4 (power, output, enable [or base]) pins.

On the other hand, the 4N29...33 have 5 junctions.

Who knows? And, mainly, who cares anymore? ;-)

Single gate FET (e.g. 2N4416) /MOSFET's (e.g. 2N6784) (3 leads) have

2N numbers; Dual gate MOSFET's (4 leads) have 3N numbers (e.g. 3N211).

I think there may have been some plain old bipolar transistors that had 4 leads... trying to recall their JEDEC numbers. And there were also some dual matched transistors in 6 pin or maybe 8 pin packages. Again I'm drawing a blank on JEDEC part numbers...

Tim.

Tim Shoppa:

Ok, sold. :-)

Screened?

Well, whatever... :-)

You sure?

6SN7 / 6AM6 / 6AU5 / 6J6 - 6.3 volt heater.

12AX7 / 12AU7 /12AT7 - 2 x 6.3 in series = 12.6.

5Z4 - 5 volt

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Yep. In tubes the first number is the approximate filament voltage.

My first audio power amplifier was 5 x 2A3 in parallel ;-) ...Jim Thompson

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               I can see November from my house :-)

You are talking about parts under the RMA 1933 scheme, aka "Committee on Tube Numbering", which I mentioned but which you unceremoniously snipped :-).

I put that in my post, to differentiate the 1933 scheme from the RMA number-letter-numbers scheme adopted in 1943 and which later became EIA and JEDEC schemes used for registered semiconductors, so that Mr. Bertolazzi might get some context.

In the 1943 scheme the numbers-after-the-letter are always bigger than

21, to help avoid confusion with the earlier scheme. I'm not going to claim the earlier scheme never got above 21 but I can't think of any examples.

I was just attempting to point out that the 1N and 2N semiconductor numbers, were a continuation of a vacuum tube numbering scheme.

First registered crystal diode was the 1N21, a 3 GHz silicon radar mixer.

Breakdown of the 1943 scheme as cribbed from Ludwell Sibley:

FIRST NUMBER: HEATER POWER

1: 0 (no filament/heater; cold cathode device, etc.) 2: Up to 10W 3: >10 to 20W 4: >20 to 50W 5: >50 to 100W 6: >100 to 200W 7: >200 to 500W 8: >500 to 1000W 9: >1000W

LETTER: TYPE OF DEVICE A: Single-element (ballasts, vaccum-type resistors) B: Diode (including protective tubes, spark gaps, voltage regulators). C: Triode D: Tetrode E: Pentode F: Hexode G: Heptode H: Octode J: Magnetically controlled (magnetron) K: Electrostatically controlled (klystrons) L: Vacuum capacitors N: Crystal rectifiers (later: solid-state devices) P: Photoemissive Q: Cavities R: Ignitrons S: Vacuum switches T: Storage, radial beam, etc.

SECOND NUMBER: SERIAL Assigned starting with 21 to avoid confusion with the 1933 scheme

3JP1 - 6.3V heater 5ABP7 - 6.3V heater

Spehro, those are RMA numbers for CRT's. Easily identified by having a "P" in them. There could be some exceptions but "P" =3D "CRT" is a pretty good indicator.

First digit: Screen diameter in inches First letters: Sequentially assigned starting from "A", then after Z starting over again with "AA", "AB", etc. THEN THE LETTER P followed by Last digit(s): Phosphor type Sometimes there's an "A", "B", etc. after the last digit to denote some later variant.

For phosphor type, 1 is normal green scope type, 7 is the slow blue phosphor.

Tim.

A little research turned up the 1N35, which was a dual 1N34. There goes my "count the number of leads and subtract one" rule :-). It also violates the "number of semiconductor junctions" rule too.

A little more researched turned up some bridge rectifiers with 3N numbers, e.g. 3N246. These have 4 wires, and 4 junctions, kinda fitting into the "number of wires minus one" rule.

I still don't have any explanation for the 6N optoisolators. They have one more wire than a 4N optoisolator....???

Tim.

Just for historical accuracy, the first number was the filament voltage. :-)

Hope This Helps! Rich

Those are CRTs (you can tell by the P1 or P7 at the end), so the numbers are probably screen diameter or something.

Cheers! Rich

Why not?

A manned vehicle has been at the bottom of the Mariana Trench, at almost 11,000 meters. That was in 1960. Since then, a couple of unmanned submersibles have also been there:

Making a pressure proof capsule to contain the electronics might be easier than trying to certify each and every component for the specific pressure. I'd guess the manufacturers don't even consider pressure when developing and manufacturing their components.

--
RoRo

Il 29/10/2010 15:20, F. Bertolazzi ha scritto:

Did you ever measured the temperature *inside* a POD?

Marco

Il 29/10/2010 14:41, who where ha scritto:

Yes. The box is filled of dielectric oil. It's a common solution, widely used.

Marco