The cause of the change in the resistance values ​​of resistors

The cause of the change in the resistance values ​​of resistors

This time I will discuss the causes of the change in the resistance value of the resistor. In the long time use resistors must be physically changed, the characters and the atomic structure of the material.

This can be affected due to excessive temperature ever experienced by the resistor, the resistor will physically expand and even though sometimes scorch resistance value has not run too far from the value in the set and the system is still able to function.

The cause of the change in the resistance values ​​of resistors

Within certain limits the circuit system will still run normally, but the circuit is more sensitive to porsentase value detainees will have problems, mainly in digital circuits.

Changes in the atomic structure of materials for the course will berubaha resistor when the resistor never experienced conditions of temperature / temperature exceeds the maximum temperature determination could be received by the fabric resistor.

Materials classified as a type of conductor on the basis of the resistor material resistivity tends to increase when exposed to excessive temperatures. it depends on the material of the resistor wrapping itself in its ability to withstand and dissipate heat in the resistor body. Insulation materials commonly in use at the resistor for example; glass, plastics etc.

Reasons for the change in the resistance value at resistordapat explain the flow and material flow calculations. Basically the current flow is the movement of electrons from one atom to another continuously under the influence of an electric field.

Electrons are negatively charged very little will be rejected by the negative electric charge and on appeal by the positive charge. Therefore, if the electric potential is applied to the conductor (positive on one side and negative on the other) then the electrons will move from atom to atom to the positive leg.

But only a few electrons are free to move and the rest are still bound to any particular atom and the magnetic field will not affect it. This means that the current flowing in the resistor material is the movement of free electrons, while the number of free electrons in a resistor affects in comparison with atoms bound is the value of the material quality manufacture, so it is a good conductor that has many free electrons and is a good insulator that almost no free electrons.

The cause of the change in the resistance values ​​of resistors

Vibration that occurs during use of the resistor is the effect of heat on the resistor body and this can affect the atomic structure of the material resistor makers. At higher temperatures the vibrations that occur in the resistor will be higher as well.

In section conductor resistor that has free electrons and high flows which cause atomic vibrations that cause collisions between free electrons with the electrons bound, at each collision energy of free electrons needed and this is the basis of a prisoner.

Increasingly squeezed atom insistence on the material, the higher the collision occurred between the atoms and the higher the resistance value of the resistor.

However , sometimes the situation of a resistor material that has little time and almost no electrons freely so that almost no current flow because the electrons in an atom bonded to. with relatively little heat on the resistor body vibrates to shake a few electron atoms and electrons that had been made ​​would bound off and become free electrons and the current will flow between the resistor terminals.

The conclusion was that the high temperature resistance of a resistor value will fall this depends on the type of conductor material and material isolatornya back ( as mentioned above ).

In the material that has increased resistance due to temperature or elevated temperatures referred to as material having a positive temperature coefficient, and vice versa if the material has a resistance value decreases as temperature / temperature increase in called as a material that has a negative temperature coefficient.

In general, the conductor is having a positive temperature coefficient, while the insulator has a negative temperature coefficient.

Material or a different material on the basis of the value of the coefficient selection of materials in the manufacture of resistors , which most likely is a material that has a very low temperature coefficient as the base material , because it will suppress the resistance value changes in extreme temperature conditions ( at the recommended limits ).

So the value of resistance remain in the range that is expected porsentase tolerance.

Type of material, temperature / temperature at the time of use is the cause of the change in the resistance values ​​of resistors.