Contents
How do I know what wattage resistor to buy?
Generally speaking the larger their physical size the higher its wattage rating. However, it is always better to select a particular size resistor that is capable of dissipating two or more times the calculated power.
What type of resistor is best for high power applications?
For very high-power applications, such as dynamic braking, nichrome wire resistors are ideal, especially when the load is expected to be hundreds or thousands of watts. Nichrome wire resistors can also be used as heating elements. Common types of resistors include: Wirewound resistors.
What name is used for a high power variable resistor?
Potentiometer is used for a high-power variable resistor.
How to choose the best resistor for your circuit?
Because for some circuits the actual type of resistor also matters. These circuits include: Which resistor type to choose for which application is beyond the scope of this article. If you are building any of these types of circuits, see if the schematics specify the resistor type. If not, maybe this article can help you out.
What kind of water do high power resistors use?
Some high power water resistors use in pulsed modes utilize copper sulfate solutions instead of saline. Liquid rheostats, or salt water rheostats, are a type of variable resistors in which the resistance is controlled by submerging the electrodes into a saline solution.
How to calculate the dissipation of a resistor?
Power dissipation in a resistor can be calculated with the formula. where P is power in Watt, V is the voltage drop over the resistor and R is the resistance of the resistor in Ohm. Let us look at an example: In this circuit, we use a LED with a voltage drop of about 2V.
What should the voltage drop be over a resistor?
That means the voltage drop over the resistor will be 9V-2V = 7V. So we need a resistor with a power rating of at least 140 mW. But preferably more. A rule of thumb is to find a resistor with twice the power rating. Here I would choose a 250 mW resistor since those are the most standard ones.