Electrical Engineering

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K H

01:47

Pure water is actually not particularly conductive. Only becomes extremely conductive with suitable solutes.

deostroll

this is hard water...

is there some article that would help me understand why "floating" pins happen?

Aiden Grossman

mouser.com/blog/dont-leave-your-pins-floating

Doesn't go into a huge amount of detail but gives a decent explanation.

Also:electronics.stackexchange.com/a/83137

laptop2d

02:06

I wanted to reach 200 rep today, I need 30 more anybody want to help me out?

deostroll

Okay in my experiment, I gave a 2.8V vcc to water, and, a wire from digital pin in input mode (pull-down with 10K resistor) was also inserted in water. The digital pin registered nothing...why would that be so?

Aiden Grossman

How far away was the wire from the digital pin from the wire providing Vcc?

They would need to be pretty close for you to get a reading with 2.8v dc

deostroll

not more than an inch apart anyway

Aiden Grossman

The resistance might still be too high for the digital pin to register. If you can, I would try bumping up the voltage to overcome the resistance.

deostroll

Could be the MCU then...! I thought the logic level of a digital pin in input mode was about 3.3V, so supplying a lower voltage probably will not register a digital read that would give a HIGH value...(I am using an arduino nano)...

Aiden Grossman

02:19

Since you are using an arudino nano, you might be able to use one of its analog pins.

5 hours later…

PlasmaHH

07:11

@Marla could also just be that value when the needle does not move

6 hours later…

Marla

12:47

@PlasmaHH . . And that is the problem ! Describing the meter readout as "nothing" could mean zero or infinity. Ambiguous statement. Not very scientific.

Daniel Tork

13:33

Hi!

I hope I do not bother anyone with this, but I don't understand where did Asmyldof go?

He is not in the room

Marla

@DanielTork He has a real life too ;)

PlasmaHH

14:18

@Marla be careful, these days you can get burned at stake for being scientific

@DanielTork I can assure you he either is alive or has a rather good text message bot

1 hour later…

Nick Alexeev

15:49

Q: Can Fortran 90 be used with Aspen Plus, or only Fortran 77?

I am attempting to write a user model in Fortran that can be connected to the Aspen Plus process simulator. Can Fortran 90 be used, or does Aspen only work with the older Fortran 77? I have checked the Aspen Plus documentation, but can find nothing about which versions of Fortran it is compatible...

When was the last time you've heard Fortran mentioned in a serious question?..

1 hour later…

PlasmaHH

17:17

@NickAlexeev many so questions about it

1 hour later…

Steve T.

18:37

As I understood, voltage / electric field propagates between wires with almost speed of light, hence we can use this feature for 2 purposes.

First, we can transfer electric power wherever we want. E.g. when I plug kettle in outlet, the voltage would force charge flow through the kettle depending on it impedance. In this case actual voltages can be very high.

Second, it can be used for transmission of information with speed of light. Telegraph, coaxial cable, PCB traces etc. Its better to use low voltages here and we give them some meaning, e.g. logic 1 or logic 0.

PlasmaHH

18:57

Not Speed of light, a factor usually about .6 to .8 c

Steve T.

@PlasmaHH Yes, but overall this is correct, right ?

PlasmaHH

19:26

It's vastly oversimplified, so it is correct in certain cases

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