# How many volts can a white LED take?

## How many volts can a white LED take?

The typical forward voltage of a white LED is in the range of 3V to 5V. Since the best choice to power white LEDs is a constant current source and the input voltage range of a Li-Ion battery is below or equal to the LED forward voltage a new power supply solution is required.

What is the white wire on LED lights?

The white will normally be the ground(-) and the black will be the positive(+). LED Lights with 3 wires will be a multi-function light. They can (most times) be used in whatever configuration is right for your application.

### What resistor do I need for a white LED?

Basics: Picking Resistors for LEDs

Power Supply Voltage LED Color Resistor (calculated)
3 V Red, Yellow, or Yellow-Green 48 Ω
4.5 V Red, Yellow, or Yellow-Green 36 Ω
4.5 V Blue, Green, White, or UV 48 Ω
5 V Blue, Green, White, or UV 68 Ω

What is the circuit diagram symbol for an LED?

The LED symbol is the standard symbol for a diode with the addition of two small arrows denoting emission (of light). Hence the name, light emitting diode (LED). The “A” indicates the anode, or plus (+) connection, and the “C” the cathode, or minus (-) connection.

## How much current does a white LED draw?

The minimum current required by most white LED types at the above voltage is 10 mA, 20 mA being the optimal range, however these devices are able to operate even with 40 mA of current, producing dazzling brightness, almost at eye blinding levels.

What is white wire in 12v?

It is standard in 12v DC automotive type wiring setups that red is positive and black is negative. It is standard in a residential AC wiring system that black is hot and white is neutral with some exceptions like when using white as a traveler for a three way switch.

### Is red positive or negative on LED lights?

For LEDs, the red wire should be positive and the black wire negative. That’s it.

How do you identify LED terminals?

Sometimes it’s easiest to just use a multimeter to test for polarity. Turn the multimeter to the diode setting (usually indicated by a diode symbol), and touch each probe to one of the LED terminals. If the LED lights up, the positive probe is touching the anode, and the negative probe is touching the cathode.

## Which pin is positive on LED?

ANODE (+)
LEDs are diodes and diodes can only allow electrical current to flow in one direction, therefore LEDs are polarised. The positive pin is the ANODE (+) and the negative pin is the CATHODE (-). It is very important that LEDs are connected to a circuit in the right direction.