Go Down

### Topic: equations (Read 878 times)previous topic - next topic

#### tinman13kup

##### Dec 13, 2016, 04:44 am
Just looking to see if anyone has a big cheatsheet of electronic equations they are willing to share.
Sure, ohm's law is easy enough, but there are so many more equations out there, and I can only remember so many of them.
Tom
It's not a hobby if you're not having fun doing it. Step back and breathe

#1
##### Dec 13, 2016, 05:27 am
V=IR
V/R = I
V/I = R
P = IV
P = I^2*R
P=V^2/R
PV=nRT
Period = 1/Frequency

What else do you need?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

#### Southpark

#2
##### Dec 13, 2016, 06:06 am
ic approx equal to ie for bipolar junction transistor (under usual operating conditions).
ic approx equal to beta*ib for bipolar junction transistor.

ic is collector current, ib is base current, ie is emitter current

#### tinman13kup

#3
##### Dec 13, 2016, 06:11 am
I see you use "V", where I learned "E" for voltage.

As for what else I need..... I was looking for a whole laundry list beyond ohms law.

transistors, mosfets, capacitors, inductors.....

Just a cheatsheet with the various equations. I've stumbled upon a few that were well laid out and easy to find what you were looking for, some just covering ohms law. I find it somewhat handy when I'm tired from dealing with the crisis of the day and just need to double check myself.
Tom
It's not a hobby if you're not having fun doing it. Step back and breathe

#### larryd

#4
##### Dec 13, 2016, 06:40 am
Welcome tinman13kup.

Quote
I learned "E" for voltage
Electromotive Force?

electronic formulas cheat sheet

No technical PMs.
If you need clarification, ask for help.

#### MarkT

#5
##### Dec 13, 2016, 01:12 pm
ideal capacitor:  C dV = I dt
ideal inductor:   L dI = V dt
resonant LC circuit:  f = 1/(2 pi) sqrt (1 / LC)
conductor in a magnetic field: F = B l I, V = B l v
RC time constant  tc = RC
RL time constant  tc = L/R
resistance of wire  R = rho l / A, rho = bulk resistivity, l = length, A = cross section area
ideal diode:   I  proportional to   e^(qV/kT), q = charge on electron, k = Boltzman's constant, T in kelvin,
or at room temp:  I roughly proportional to e^(39 V), doubles every 18mV or so, x10 every 59mV
[ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]

#### MarkT

#6
##### Dec 13, 2016, 01:17 pm
You can derive:

energy in capacitor:   E = 0.5 C V^2
energy in inductor:    E = 0.5 L I^2
characteristic impedance of transmission line = sqrt (L/C)  - where L and C are inductance and capacitance
per unit length.
[ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]

#### TomGeorge

#7
##### Dec 13, 2016, 01:41 pm
Twinkle Twinkle Little Star Power Equals I square R.

Tom...
Everything runs on smoke, let the smoke out, it stops running....

#### MarkT

#8
##### Dec 13, 2016, 02:27 pm
PV=nRT
You sneaked in the ideal gas law!  Don't think I've needed that for electronics yet
[ I DO NOT respond to personal messages, I WILL delete them unread, use the forum please ]

#### jackrae

#9
##### Dec 13, 2016, 02:35 pm
You sneaked in the ideal gas law!  Don't think I've needed that for electronics yet
Might be useful for calculation of how much magic smoke was released

#### tinman13kup

#10
##### Dec 13, 2016, 10:04 pm
Twinkle Twinkle Little Star Power Equals I square R.

Tom...
NOOOOO!!! Make it stop!!! The voices in my head!!

Tom too
Tom
It's not a hobby if you're not having fun doing it. Step back and breathe

#### terryking228

#11
##### Dec 14, 2016, 03:04 am
And JUST when I thought this was getting really boring, I found the holiday shopping solution for two of my Grandchildren: HERE

Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

#### larryd

#12
##### Dec 14, 2016, 03:11 amLast Edit: Dec 14, 2016, 03:11 am by LarryD
That really looks like someone from way back:

No technical PMs.
If you need clarification, ask for help.

#### tinman13kup

#13
##### Dec 14, 2016, 03:17 am
That really looks like someone from way back:

Wonder how long it would take people to notice that??

Tom
It's not a hobby if you're not having fun doing it. Step back and breathe

Go Up