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A metal film resistor is a passive resistor. It uses a thin film of metal alloy deposited around a ceramic cylinder to provide the current path of the resistor. The ceramic cylinder provides mechanical strength to the resistor. The tolerance of the metal film resistor is quite lower than that of the carbon composition resistor … Read more
A carbon film resistor is first made by depositing a thin layer of carbon onto a ceramic (usually alumina) cylindrical substrate through a process called pyrolysis or vacuum deposition. Then, during construction, the carbon film is carefully trimmed or spiraled to achieve the desired resistance value. After that, metal end caps and lead wires are … Read more
What is a Carbon Composition Resistor? A carbon composition resistor is a simple electronic component. Engineers use it to control current flow in circuits. This resistor contains carbon particles mixed with clay material. Construction and Manufacturing Manufacturers follow a simple process to make these resistors. First, they mix fine carbon powder with ceramic clay. The … Read more
What is resistivity? Understand specific resistance, its units (ohm-meter), how material, length, area, and temperature affect conductor resistance. Laws of Resistance The resistance offered by a conductor depends upon four major factors. Length of the Conductor: One factor is the length of the conductor. That means if we increase the length of the conductor without … Read more
Electrical resistance is the opposition to electric current flowing through a conductor. Simply put, it blocks or reduces the movement of electrons through a conductor. When an electric current flows through a conductor, electrons drift from one end to the other end of the conductor. During this drifting, the moving free electrons collide with atoms … Read more
Let us discuss the effect of temperature on resistance. When the temperature of a conductor increases, its resistance also increases. This relation is linear. In other words, the change in resistance is directly proportional to the change in temperature. Mathematical Relationship If R1 is the initial resistance of a particular resistor or conductor at T1 … Read more
German physicist Georg Simon Ohm published his remarkable findings in 1827. This was the relationship between voltage, current, and resistance. We refer to this as Ohm’s Law. What Exactly is Ohm’s Law? Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across the conductor and inversely proportional to … Read more
Not only a power transformer, but all transformers have only two main parts. These are the windings and the core. All other parts associated with the transformer are just there to support the working of the transformer. Actually, the principle of a transformer is based on these two elements — the winding and the transformer … Read more
An Oil Surge Relay, or OSR, is a type of mechanical relay. It operates in response to a sudden oil surge. Need for Separate Diverter Tank Every modern power transformer includes an On-Load Tap Changer (OLTC). During tap-changing operations, some arcing always occurs at the diverter switch contacts. It is desirable to change tap positions … Read more
The Buchholz Relay is a gas-actuated protection relay. It is a mechanical relay. All oil-immersed transformers that have a conservator tank should be equipped with a Buchholz relay. A Buchholz relay can detect both slow-developing faults and major transient faults occurring within the transformer. It provides an early warning (alarm) for slow-developing faults and initiates … Read more