logo

Formulas

inch
to
millimeters
X 25.4
inch
to
centimeters
X 2.54
inch
to
Meters
X .0254
inch
to
feet
X .0833
millimeters
to
centimeters
X .100
millimeters
to
feet
X .00328
millimeters
to
inch
X .03937
millimeters
to
meters
X .00100
centimeters
to
millimeters
X 10.0
centimeters
to
feet
X .0328
centimeters
to
inch
X .3937
centimeters
to
meters
X .0100
feet
to
centimeters
X 30.48
feet
to
inch
X 12.0
feet
to
meters
X .3048
feet
to
millimeters
X 304.8
meters
to
centimeters
X 100
meters
to
inch
X 39.37
meters
to
feet
X 3.28
meters
to
millimeters
X 1000

Area
inch^2 to centimeters^2 X 6.452
inch^2 to feet^2 X .006944
inch^2 to millimeter^2 X 645.2
inch^2 to meter^2 X .0006452
centimeter^2 to inch^2 X .1550
centimeter^2 to feet^2 X .001076
centimeter^2 to millimeter^2 X 100
centimeter^2 to meter^2 X .0001
millimeter^2 to inch^2 X .001550
millimeter^2 to centimeters^2 X .0100
millimeter^2 to feet^2 X .00001076
millimeter^2 to meter^2 X .000001
meter^2 to inch^2 X 1550
meter^2 to centimeters^2 X 10000
meter^2 to feet^2 X 10.76
meter^2 to millimeter^2 X 1000000
feet^2 to millimeter^2 X .000929
feet^2 to centimeter^2 X 929.0
feet^2 to inch^2 X 144.0
feet^2 to meter^2 X .0929

 

Volume
inch^3 to feet^3 X .0005787
inch^3 to centimeters^3 X 16.39
inch^3 to meters^3 X .00001639
inch^3 to liters X .01639
feet^3 to centimeters^3 X 28320
feet^3 to inch^3 X 1728
feet^3 to meters^3 X .02832
feet^3 to liters X 28.32
centiimeters^3 to inch^3 X .06102
centiimeters^3 to feet^3 X .00003531
centiimeters^3 to meters^3 X .000001
centiimeters^3 to liters X .001
liters to centimeters^3 X 1000
liters to inch^3 X 61.02
liters to feet^3 X .03531
liters to meters^3 X .001

 

Electronics
In many electrical circuits, the values of components are specified in units with prefixes. This makes the numbers easier to handle without long strings of zeros.
mega = X 10^6
kilo = X 10^3
milli = X 10^-3
micro = X 10^-6
nano = X 10^-9
pico = X 10^-12

E = Potential

Difference (volts)

I = Current

(amperes)

R = Resistance

(ohms)

P = Power

(watts)

 

Potential Difference (volts)

I X R

SQRT( P X R )

P / I

Current (amperes)

E / R

P / E

SQRT ( P / R )

Resistance (ohms)

E / I

E^2 / P

P / I^2

Power (watts)

E X I

I^2 X R

E^2 / R

Resistances in series

RT = R1 + R2 + R3 …. + Rn

Resistances in parallel

1/RT = 1/R1 + 1/R2 + 1/R3… + 1/Rn

Resistances in parallel

(2 components)

RT = (R1 X R2) / (R1 + R2)

Capacitances in series

1/CT = 1/C1 + 1/C2 + 1/C3… + 1/Cn

Capacitances in parallel

CT = C1 + C2 + C3 …. + Cn

6dB High Pass

Series Cap = .159 / ( Impedance X Frequency )

6dB Low Pass

Series Inductor = Impedance / (6.28 X Frequency )

12dB Butterworth (high and low pass)

Capacitor = .1125 / ( Impedance X Frequency )

Inductor = ( .2251 X Impedance ) / Frequency

Attenuation Circuit

Attenuation Circuit

 

Attenuation

in dB

2 Ohms
4 Ohms
8 Ohms
R1
R2
R1
R2
R1
R2
1 .25 16 .5 33 1 60
2 .5 7.5 .8 15 1.6 31
3 .66 5 1.2 10 2.5 20
4 .75 3.4 1.5 6.2 3 13
5 .83 2.5 1.7 5 3.4 10
6 1 2 2 4 4 8
7 1.1 1.8 2.2 3.4 4.3 6.6
8 1.2 1.4 2.5 2.75 5 5.2
9 1.3 1.2 2.5 2.2 5.2 4.3
10 1.4 .83 2.75 1.87 5.5 3.75

 

Zobel Network

Zobel Network

Resistor = 1.25 X Re

Capacitor = Inductance / Resistor2

Series Notch Filter

Series Notch Filter

Capacitor = .1592 / ( Re X Qes X Fs )

Inductor = (.1592 X ( Qes X Re ) ) / Fs

Resistor = Re + ( ( Qes X Re ) / Qms )

Series Notch Filter

Leave a comment