Theory
Resistance reading
Resistors (resistor) is the basic equipment needed for electronic circuits have different shapes according to usage.
Types of Resistors Various types of applications: 1. Constant 2. Resistors Resistors variable resistors 3. Special.
1. Resistors constant. By the means of production
1.1 resistor made from carbon.
It uses compressed carbon rod and a mixture of substances that are mixed with a conductor resistance value depending on the mixture of the two. Currently not widely used Due to the resistance to change when the heat and humidity.
1.2 resistor made from coils.
Called Resistors Wire gloss wide (wire wound resistor) is at the core of the coil insulation. The coil is made from a mixture. Therefore, the resistance has to be based on the type of substance. The length of the wire And small or growing resistance of the wire, which is resistant to high power.
1.3 Carbon Film Resistors (Carbon film resistor).
Made of layers of carbon generated on the surface of glass or metal, such as heat-resistant ceramic resistance value is determined by the length and thickness of the carbon layer. The exact resistance value Tolerances and temperature coefficient of less than compressed carbon rods. Can be applied to the coils have the advantage of a low electrical inductance. Used in high frequency circuits as well.
1.4 Resistors Metal or metal film (metal film resistor).
Like carbon film Only use metal film or a film that only carbon fiber instead of metal. The resistance to static The resistance may be changed By changing the type or thickness of the metal lining, metal or resize the advantage of keeping the temperature coefficient is zero. The very high stability May be used in temperatures of 255 degrees Celsius. Very little noise Ideal to be used in circuits with high sensitivity, such as computers, aviation and so on.
1.5 Resistors powder tin (tin oxide resistor).
Tin plate holder attached to the glass. Tin powder happens to be a stiff resistance to scratches well. The expansion of glass designed to fit with the expansion of the tin powder. Can increase the resistance by cutting out some tin powder to a minimum. Drill a spiral around a glass rod with a high chemical stability advantages are there.