What is the formula for power rating?
Calculate power rating in KVA when you know voltage and output resistance. Use the formula: P(KVA) = (V^2/R)/1000 where R is resistance in ohms. For example, if V is 120 volts and R is 50 ohms, P(KVA) = V^2/R/1000 = (14400/50)/1000 = 288/1000 = 0.288 KVA.
How do you calculate the value of a resistor?
Calculating the value of the series resistor
- 6 = 2 + V R.
- V R = 4 V.
- V = I R.
- 4 = 0.01 × R.
- R = 400 Ω
What are the 4 types of resistors?
Different Types of Resistors – Fixed, Variable, Linear and Non-Linear Resistors & Applications
- Carbon Composition Resistors.
- Wire wound Resistors.
- Thin Film Resistors.
- Carbon Film Resistors.
- Metal Film Resistors.
- Thick Film Resistors.
- Metal Oxide Resistors.
- Cermet Oxide Resistors (Network Resistors)
What is resistor power rating?
The power rating of a resistor indicates how much power a resistor can handle before it becomes too hot and burns up. Power is measured in units called watts. The more watts a resistor can handle, the larger and more expensive the resistor is. Most resistors are designed to handle 1/8 W or 1/4 W.
What is resistor value?
Resistors. A resistor is a device that opposes the flow of electrical current. The bigger the value of a resistor the more it opposes the current flow. The value of a resistor is given in ohms and is often referred to as its ‘resistance’.
How do you find the maximum and minimum value of a resistor?
Take the nominal value and multiply it by 1 + your tolerance, which is (1+0.1). Then take the nominal value and multiply it by 1 – tolerance, or (1-0.1). The highest possible value is 517 K.
What are the 2 types of resistance?
Resistors can be broadly of two types. Fixed Resistors and Variable Resistors.
What are the two major categories for resistors?
The two major types of resistors that can be seen are variable and fixed resistors.
Why do resistors have to be rated above 70 °C?
Often, to provide a safety margin, the resistor power rating is chosen above the electric power expected for the application. Typically resistors are rated for a temperature of 70 °C, above this resistor starts to derate. This means that above this temperature the resistor can only safely operate at a reduced power level.
What’s the maximum power a resistor can dissipate?
When a resistor has a power rating of 2W, a maximum of 2W power can be fed to it for all combinations of voltage and currents as long as possible. Some resistors are designed for larger power dissipation. These are called Power Resistors. Resistors with power rating of at least 5W come under power resistors.
Is the power rating of a resistor a key parameter?
For most electronic circuits the power rating is not a key parameter, since those resistors dissipate low amounts of energy of one watt or less. In power electronics however, the power rating is an important characteristic. Generally speaking hereto is referred when power ratings are one watt or higher.
When do you use a power resistor what does it do?
In power electronics however, the power rating is an important characteristic. Generally speaking, a power resistor is referred to when the power ratings are one watt or higher. Typical applications include power supplies, dynamic brakes, power conversion circuits, power amplifiers, and heaters.