Tag Archives: resistor

Standard Resistor Values

Resistors and Capacitors are types of passive electronic components. The basic unit of resistance is the ohm (Ω) and capacitance is Farad.

Standard base resistor values are given in the following tables for the most commonly used tolerances (1%, 2%, 5%, 10%), along with typically available resistance ranges.

In 1952 the IEC (International Electrotechnical Commission) decided to define the resistance and tolerance values into a norm, to ease the mass manufacturing of resistors. These are referred to as preferred values or E-series, and they are published in standard IEC 60063:1963. These standard values are also valid for other components like capacitors, inductors and Zener diodes. The preferred values for resistors were established in 1952, but the concept of the geometric series was already introduced by army engineer Renard in the 1870s. Continue reading Standard Resistor Values

Resistor Color Code Calculator

The electronic color code is used to indicate the values or ratings of electronic components, usually for resistors, but also for capacitors, inductors, diodes and others. A separate code, the 25-pair color code, is used to identify wires in some telecommunications cables.

Standard Resistor and Capacitor values with IEC and EIA code is explained in previous post.

This tool is used to decode information for color banded axial lead resistors. Select their colors to determine the value and tolerance of the resistor.

Continue reading Resistor Color Code Calculator

Measurement of Low value resistance (0.1 to 50 Ohm)

The previous voltage divider design is suitable for only measurement of higher values of resistance (50 Ohm to 1 MOhm) to measure very small value resistance we have built this circuit, it consists of constant current source of 100mAmp. Measuring voltage drop across a resistor having constant current gives us resistance value (R = V / I).
V = I x R
R = V / I Continue reading Measurement of Low value resistance (0.1 to 50 Ohm)

DC Current Measurement using Shunt Resistor

Designing of Digital Ammeter is basically a process of converting a voltmeter into Ammeter. We know that V=I x R. From this we can say that Voltage drop across resistor (shunt) is directly proportional to the current (V = I). In ammeter this resistance is called Shunt. Shunt resistance have very small value and it will not affect the load voltage. Most commonly 75mV shunts are available in market. Or you can use low value resistance. Continue reading DC Current Measurement using Shunt Resistor