# Quick Answer: What Is The Best Type Of Resistor?

## Does a 12v LED need a resistor?

If this is a “12V” LED, which generally will consist of several LED chips in combination, no resistor is required..

## How do you tell the difference between resistors?

Some resistors have contact plates on the bottom. Read the 3 or 4 numbers on the resistor. The first 2 or 3 represent the significant digits and the last indicates the number of 0s that should follow. For example, a resistor reading 1252 indicates a rating of 12,500 ohms or 1.25 kilo-ohms.

## Can I use a different resistor?

Sometimes you need a resistor with a value you don’t have in your kit. Instead of ordering and wanting for a resistor with a value you need you can change the resistance of a resistor by using another resistor or many. By installing resistors in a parallel or series circuit you can change the value in Ohms.

## How do you know if a resistor is bad?

Pick out a random resistor and set the multimeter to the 20kΩ setting. Then hold the probes against the resistor legs with the same amount of pressure you when pressing a key on a keyboard. The meter will read one of three things, 0.00, 1, or the actual resistor value.

## Do I need a resistor for LED?

The simplest circuit to power an LED is a voltage source with a resistor and an LED in series. … The ballast resistor is used to limit the current through the LED and to prevent that it burns. If the voltage source is equal to the voltage drop of the LED, no resistor is required.

## How do you calculate resistance needed?

Calculate the ohms of resistance (R) you need by using the formula R = V ÷ A, with V equaling the volts you’re stepping down (3) and A equaling the amps in your circuit. Once you know your resistance, you can decide whether you want to use a single resistor or if you want to break it down across multiple resistors.

## What size resistor should I use with an LED?

Basics: Picking Resistors for LEDsPower Supply VoltageLED ColorResistor (rounded)5 VRed, Yellow, or Yellow-Green150 Ω5 VRed, Yellow, or Yellow-Green56 Ω9 VRed, Yellow, or Yellow-Green75 Ω9 VBlue, Green, White, or UV100 Ω4 more rows•Aug 29, 2012

## How do I know what resistor to use with LED?

We’ll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms. To use several LEDs in parallel, sum the current values.

## What is tolerance in a resistor?

The tolerance of a resistor is the maximum difference between its actual value and the required value and is generally expressed as a plus or minus percentage value. For example, a 1kΩ ±20% tolerance resistor may have a maximum and minimum resistive value of: Maximum Resistance Value.

## What type of resistor should I use?

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. Usually, you can just use the cheapest resistor you can find with the correct power rating.

## What are the 4 types of resistors?

Different Types of Resistors – Fixed, Variable, Linear & Non-Linear Resistors & ApplicationsCarbon 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)More items…

## What happens if you don’t use a resistor?

When hooking up an LED, you are always supposed to use a current-limiting resistor to protect the LED from the full voltage. If you hook the LED up directly to the 5 volts without a resistor, the LED will be over-driven, it will be very bright for a while, and then it will burn out.

## What is MFR resistor?

Metal film resistors have a thin metal layer as resistive element on a non-conducting body. … Other film type resistors are carbon film and thick and thin film resistors. In most literature referrals to metal film, usually it is a cylindrical axial resistor.

## Do resistors waste power?

But the energy dissipated by a resistor used in a circuit is almost always “wasted” energy in a sense. A resistor turns valuable electrical energy into heat. Unless this heat is used productively (in a baseboard heater, for example) that heat is normally considered wasted.

## Does it matter if the resistor is before or after the LED?

It doesn’t matter! The resistor can go before – or after – the LED, and it will still protect it. You see.. the current that flows out of a battery is always equal to the current that flows back in to the battery. … The current through the resistor is the same as the current through the LED.

## What is the point of a resistor?

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.

## What do resistors look like?

A resistor is a little package of resistance: wire it into a circuit and you reduce the current by a precise amount. From the outside, all resistors look more or less the same. As you can see in the top photo on this page, a resistor is a short, worm-like component with colored stripes on the side.

## What does a resistor limit?

In short: Resistors limit the flow of electrons, reducing current. Voltage comes about by the potential energy difference across the resistor. The mathematical answer is that a resistor is a two-terminal electric device which obeys, or you could say enforces, Ohm’s law: V=IR.

## Which type of resistors is more reliable and why?

Metal Oxide Film These durable resistors feature a better reliability and stability than metal film resistors. Furthermore the operating temperature is higher. Therefore they are more used in applications requiring a high endurance.

## What are the two main types of resistors?

Basic distinction of resistor typesFixed resistors: Fixed resistors are by far the most widely used type of resistor. … Variable resistors: These resistors consist of a fixed resistor element and a slider which taps onto the main resistor element.

## What does R mean in resistors?

resistance of resistorI = current through resistor in amps (A) R = resistance of resistor in ohms ( ) V = voltage across resistor in volts (V)