Limit Current Using Resistor

March 19, 2018

So you know that you need a 200 ohm resistor. Since the voltage across it is proportional to the current this voltage can be used to control the current flow through the pass.

Switch Mode Power Supply Current Sensing Part 1 The Basics

13 8v 20a Power Supply Looking To Add Adjustable Current

Led Calculator For Single Leds

Choosing the right resistor.

Limit current using resistor. Lets say you are using the led above with a supply voltage of 12v an led forward voltage of 39v. So its easy to see now how any voltage can be obtained with a resistor voltage divider circuit. Some components such as light emitting diodes are very sensitive to current.

As we know a voltage of about 18v leds like the most proper light not heat and power consumption of approximately 10ma to 20ma only. Current limiting is the practice in electrical or electronic circuits of imposing an upper limit on the current that may be delivered to a load with the purpose of protecting the circuit generating or transmitting the current from harmful effects due to a short circuit or similar problem in the load. Current limiting resistor for led and load.

You need to be sure the wattage power rating for your resistor is sufficient for the power being used. A few milliamps of current is enough to make an led glow. To check calculations for voltage dividers see the voltage divider calculator.

Today my son learn to use the led for the 3v battery. The current sensor itself can be a simple low value resistor. Well the only thing you need to be aware of is the wattage rating of the component.

A few hundred milliamps is enough to destroy the led. One of the most common uses for resistors is to limit the current flowing through an electronic component. How to use it with 3v or more voltage power supply.

So the necessary value for the current limiting resistor is 200 ohms. So we can use a 25kw resistor as our r2 resistor with the r1 resistor being 10kw. The equation for power is.

But when you look for components you find that there are several different types of resistors. The resistors purpose is to limit current and thus uses some amount of power.