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- 1.Basic knowledge of resistors

**・Resistors**- ・Capacitors
- ・Inductors (coils)

Ohm’s law is applicable to resistors

Possible usage of resistors under Ohm’s law.

**・Deciding voltage****・Deciding current**- ・Measuring current
- ・Consuming power（converting electricity to heat）

V_{out} = R_{2}/(R_{1}+R_{2})

I= Vin/(R_{1}+R_{2})

I= I_{1}= I_{2}

In series, voltage is proportional to the resistance

I= I_{1}+ I_{2}

V_{out}= V_{2} = V_{1} = Vin

R_{1}：R_{2}＝I_{2}： I_{1}

In parallel, voltage is the same on each resistors

Current is negatively proportional to resistance

The resistive value is expressed in 3 or 4 digit numbers following E-series. E-series are geometric progression series and depending on how many numbers used between 1 and 10, they are called E12, E24, and E96 series.

**E12 series is a geometric progression**

^{12}10^{n} Substitute “n”with 0…11, and you get1.0, 1.2, 1.5, … 8.2,

12 values with same ratio.

E24 series adds a number in between each of the E12 series, making them 24 numbers.

^{12}10^{n}

Resistance value is expressed in 3 or 4 digit alpha numeric number on top of the products unless the surface is too small to mark.

⇒Significant figures are expressed in E series.

Chip resistors currently ranges from mΩ（milliohms）to MΩ（mega Ohms). Using the power of 10 and E series, resistance value is expressed as follows. The number of digits changes depending on the size and resistance value(For details, refer to the each product series. E-series are described on page 7 of the catalogue. )

Resistance value range and units

E6, E12, E24 series has 2 significant figures

Last digit is n of 10^{n}

n=1 ⇒10^{1}= 10

n=2 ⇒10^{2}= 100

n=3 ⇒10^{3}= 1000

R means decimal point under 10Ω

3 digit designation

102=> 10 x 100 = 1kΩ

331=> 33 x 10 = 330Ω

3R0=> 3.0 Ω

*Refer to page 7 of the catalogue for 3 digits expression of E96 series

E96 series has 3 significant figures

Last digit is n of 10^{n}

n=1 ⇒10^{1}= 10

n=2 ⇒10^{2}= 100

n=3 ⇒10^{3}= 1000

Under 1Ω, numbers after decimal point is expressed in 3 digits after R

4 digit designation

1002=> 100 x 100 = 10kΩ

4990=> 499 x 1 = 499Ω

3303=> 330 x 1000= 330kΩ

3R00=> 3.0Ω

R220=> 0.22Ω =220mΩ

R005=> 0.005Ω = 5mΩ