glossary of electronic math terms.

[Groover]

I find a stumbling block for me, when trying to understand electronic formulae, is the use of terms* in equations the definitions of which are assumed to be understood. By this I infer that these terms must be somewhat standardized.

Does anyone have a link to a list of these terms and the definitions of same?

*examples would be Ra, Rk, Va, Vs, Vg - I know what these terms mean, they are just examples of what I mean by the term "terms"

Thanks

[Old Tele man]

...there ain't no absolutes!

...for instance, tube plate resistance (rp) = tube anode resistance (ra)

...sort of a 'toe-mah-toe" or "toe-may-toe" situation depending upon *how/where* you learned your electronics, ie: tube (USA) = valve (europe), etc.

[defaced]

That makes two of us. I've yet to find a glossary of terms/abbreviations.

Here's a thread I started on the same topic a while ago, maybe you can get something from it. http://music-electronics-forum.com/t10427/

[Enzo]

But there are typical uses.

The first letter generally refers to whatever the heck it is, while the second letter specifies a subset. For example R almost always refers to "resistor." Rp = Ra = resistor for plate/anode. The plate resistor. Rg might be a grid resistor, and Rk a cathode resistor. They usually use k for cathode, C is already mostly used for capacitor. There is nothing special about the resistor itself, it just defines its use. A 100k plate resistor and a 100k cathode resistor and a 100k grid resistor would be identical resistors, just used different ways. C means capacitor, so Ck would be the cathode resistor.

In a schematic we usually number each part, so all the resistors get a number. R101, R102, R103. Or R1, R2, R3. Some schematics just number all the resistors in sequence. Other schematics use the 100s series to separate sections of the amp. For example all the preamp resistors would be in the R100 series, and al the power amp resistors in the R200 series, and the power supply resistors in the R300 series, and the draft resistors in the R-U-in-Canada series. (sorry, 1960s reference)

Those R numbers identify which part in the schematic, but not the function. Rk tells its function but not which one. If we talk about a one tube circuit to discuss some electronic concept, we use Rp, Rk. But in a typical amplifier, there are a bunch of Rks scattered through the amp, so we stick to R101. Mostly.

R - resistor
C - capacitor
L - inductor - also called choke or coil
Q - transistor, though some drawers like to use T or TR for transistor.
U - integrated circuit. SOme drawers just use IC.
D - diode
CR - diode (from Crystal Rectifier)
K - relay, though some use RL or RY
Y - we don;t see it much here, but it means a crystal, used in high frequency oscillators.

Pots = potentiometers = controls Your basic volume or tone control. SOme drawings just call them another resistor, R101. SOme call them out with their own designation like VR for variable resistor.

ANd "V." V is interesting. It means Valve or Tube. SO V1 V2 etc are your tubes. But V also means voltage. WHich points out that context matters. V1 might mean my preamp tube, but I could have a solid state amp that has not tubes and still find "V1" where it might refer to a power supply voltage. SO from your examples, we might find Vp for plate voltage, Vs for screen grid voltage. (We often just call screen grids just screens) Vg for grid voltage. it should be clear from the context whether the particular V refers to a part (the tube) or a voltage.

Current is measured in amperes = amps, so we might have a current of 10A, meaning 10 amps. However when we refer to a particular instance of current in an amp, we use "I" for it. SO the plate current through a tube would be Ip. And if Ip, I always wash my hands. SO A for current means amps, an amount, whereas I means where it is. Ik = cathode current.

Again, context matters. Transistors have typically three terminals - emitter, base, and collector - EBC. I hate to say this, but they correspond roughly with a tube cathode, grid, and plate. We use lower case in the second letter spot. So Ic means collector current, not the same as IC which means integrated circuit. (IC also can refer to a brand of capacitor - Illinois Capacitor. But you would never see that written on a schematic.)

There are tons of designations and references. Those are a few common ones. ANy basic electronic text will cover this.

[Groover]

by the way I don't have any trouble with the schematics, only with the formulae.

What does ^ mean as in 10^2 ? Does this symbolize an exponent?

[defaced]

What does ^ mean as in 10^2 ? Does this symbolize an exponent?

Yes, ^ = exponent. This is pretty universal, for example, the TI-83 uses ^ for exponent, as does Excel.

[Bruce / Mission Amps]

Yes, ^ = exponent. This is pretty universal, for example, the TI-83 uses ^ for exponent, as does Excel.

And in plain English, 10^2 means 10 squared, or 10x10 = 100

[Old Tele man]

...today, it is 10^2 = 10 x 10 = 100 (from BASIC syntax)

...or it could be 10**2 = 10 x 10 = 100 (from FORTRAN syntax)

[Merlinb]

To add to what Enzo said, it is also worth knowing that upper-case letters are usually used to denote fixed or DC things, which lower-case letters are used for AC things.

Examples:

Ra = anode resistor (it's a resistor. That's it)
ra = anode resistance (the internal resistance which only applies for signal currents, but not DC)

Va = anode voltage
va = signal voltage at the anode (ignoring the DC bit).

Older books also tend to use E or e instead of V or v for voltages (the E stands for EMF). This has largely gone out of fashion now though.

It has always surprised me that there is no standard symbol for "gain". Most people use 'A', but some also use G, M, or any other random letter. (I have started using A for the gain of an active circuit, and B for the gain of a passive circuit, which is actually a loss)

[tubeswell]

...R almost always refers to "resistor."

They usually use k for cathode

C means capacitor

So Ck would be the cathode resistor.

Oops! (Don't ya mean "cathode (bypass) capacitor"?)

[Enzo]

Well yes, now that you mention it, that WAS what I intended to say.

Sorry.

I'll just pretend it was an April Fool's Day joke.