Electronics and Embedded Programming V2 - Developers

U and E are technically valid and more common when you start talking about electric fields. You'll generally want to stick to V though to avoid confusion.

It largely depends on the context. Many physics texts are going to use a script 'E'.

V is the unit (Volt), U ist the letter for it. A mechanical analogy: Velocity "Meters per Second" is a unit, v is the letter for velocity.

Actually, I think the different symbols actually have different meanings. 'V' is generally relative to some ground level (or difference across some component/network), whereas script-E is absolute. I'm not sure I've ever seen 'U' used, but it's usually the symbol for potential energy, which I guess you could measure electric potential in, as the potential energy of an electron in that field, in eV. Maybe it varies by country, too? Physics notation is pretty standard, but I think some of the EE notation varies by region?

Just asked around, friends from the Netherlands, Germany and Slovakia all said they learned to use U to denote voltage, with Volt as the unit.

Yeah, in the US we usually use V for constant voltages, v(t) for time-varying, V[sub]CC[/sub]/V[sub]DD[/sub]/V+ for positive supply, V[sub]EE[/sub]/V[sub]SS[/sub]/V- for negative supply, etc. So I guess it varies.

[QUOTE=ROBO_DONUT;34432243]Yeah, in the US we usually use V for constant voltages, v(t) for time-varying, V[sub]CC[/sub]/V[sub]DD[/sub]/V+ for positive supply, V[sub]EE[/sub]/V[sub]SS[/sub]/V- for negative supply, etc. So I guess it varies.[/QUOTE] As I said, U ist the quantity while V is the unit of the quanitity. If you're talking about a specific voltage (like 5V or V[sub]CC[/sub] or V[sub]EE[/sub]), you use volts, but in a formula you will use U. For example, the energy stored in a capacitor is E = 1/2 * C * U²

So far in school all of the material has used U, maybe it's a european thing.

[QUOTE=DrLuke;34432562]As I said, U ist the quantity while V is the unit of the quanitity. If you're talking about a specific voltage (like 5V or V[sub]CC[/sub] or V[sub]EE[/sub]), you use volts, but in a formula you will use U. For example, the energy stored in a capacitor is E = 1/2 * C * U²[/QUOTE] I got that. V is used for [i]both[/i] the unit [i]and[/i] the variable here. So you could write something like I[sub]R[/sub] = V[sub]R[/sub]/R for the current through a resistor, V[sub]CC[/sub]=5V to specify supply voltage, and energy stored in a capacitor would be written as U=1/2*C*V[sup]2[/sup]. We use U for potential energy. E is total energy, and, occasionally, electric potential in media where script-E would be difficult to typeset. So we are, in fact, using different conventions. Surely you guys have come across this notation before, though? All the datasheets I've ever looked at (most online) have used the US convention, with the exception of a datasheet for a vaccuum tube that was manufactured in eastern Europe, which used 'U' for voltage, like you guys are saying. I just vaguely remember that, now, I didn't think much of it at the time because I read it as 'potential energy' and it still made sense since ℰ(in V)=U(in eV) when q=e.

We use E for electric fields and an E with a ~ on top of it for Energy.

Did a bit of research, U stands for Unterschied (difference), and it is forbidden in SI to use the same symbol for the quantity (voltage) and unit (Volt), that's why we use U. (Just think about it, V = 6V looks really confusing)

[QUOTE=VistaPOWA;34433631]Did a bit of research, U stands for Unterschied (difference), and it is forbidden in SI to use the same symbol for the quantity (voltage) and unit (Volt), that's why we use U. (Just think about it, V = 6V looks really confusing)[/QUOTE] That actually makes perfect sense.

anyone here ever used the internal temperature sensor?

[QUOTE=SubbyV-2;34440565]anyone here ever used the internal temperature sensor?[/QUOTE] Of what?

Just found out that sure-electronics sell some nice indicator tubes, [url]http://www.ebay.nl/itm/Magic-Eye-6E2-EM87-Electron-Tube-with-Caromic-Socke-/250975479106?pt=LH_DefaultDomain_0&hash=item3a6f4de542#ht_2471wt_1163[/url].

[QUOTE=DrLuke;34443420]Of what?[/QUOTE] The arduino/atmega328

[QUOTE=SubbyV-2;34440565]anyone here ever used the internal temperature sensor?[/QUOTE] Maybe you should read the datasheet which has all the info on using it ?

[QUOTE=Chryseus;34445293]Maybe you should read the datasheet which has all the info on using it ?[/QUOTE] I don't remember ever asking how to use it? i was asking if anyone had used it, wasn't i?

[QUOTE=DrLuke;34433161]We use E for electric fields and an E with a ~ on top of it for Energy.[/QUOTE] E stands for Electricity-ness.

[QUOTE=Nikita;34448882]E stands for Electricity-ness.[/QUOTE] E stands for electromotive force. We -here in the Europa's- use it to denote the voltage over a power source. We use U for the voltage over an individual component (such as a resistor, a diode or your nipples).

We also use square resistor symbols in England, much easier to draw I think. [img]http://www.bbc.co.uk/scotland/learning/bitesize/higher/physics/images/test_bite2a.gif[/img]

It was a joke.

[QUOTE=Chryseus;34449985]We also use square resistor symbols in England, much easier to draw I think. [img]http://www.bbc.co.uk/scotland/learning/bitesize/higher/physics/images/test_bite2a.gif[/img][/QUOTE] I prefer squiggly lines

Does anyone still use Schematic jumps? [IMG]http://www.kpsec.freeuk.com/symbols/wirenj.gif[/IMG] I find them useful in relatively large schematics when wires are almost all clustered together into a rats nest..

The guy in the local electronics shop gave me 5 7-segment displays. After not being able to do shit with them, I checked the datasheet once more. They run on 12V. I specifically asked for 5V ones. Retard.

[QUOTE=VistaPOWA;34454017]The guy in the local electronics shop gave me 5 7-segment displays. After not being able to do shit with them, I checked the datasheet once more. They run on 12V. I specifically asked for 5V ones. Retard.[/QUOTE] Are they LEDs only? Because then the voltage isn't really important as long as the current requirements are met. Link to datasheet please.

Turns out I read the spreadsheet bad. And my wiring wasn't perfect. Works now, although it displays everything that it shouldn't.

[QUOTE=ddrl46;34443915]Just found out that sure-electronics sell some nice indicator tubes, [url]http://www.ebay.nl/itm/Magic-Eye-6E2-EM87-Electron-Tube-with-Caromic-Socke-/250975479106?pt=LH_DefaultDomain_0&hash=item3a6f4de542#ht_2471wt_1163[/url].[/QUOTE] Would someone be able to answer whether these take +-10V for the grid or something else?

[QUOTE=SubbyV-2;34458914]Would someone be able to answer whether these take +-10V for the grid or something else?[/QUOTE] 0v - -10v.

[QUOTE=ddrl46;34459088]0v - -10v.[/QUOTE] how do i get 12V to -10v?