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How can you tell which way a led goes in a circuit?
I have three simple ways to remember which way round an LED goes in a circuit. 1, Looking down from the top of the LED there is usually a flattened edge, this identifies the negative pin of the LED. 2, If the LED is new, there will be one lead longer than the other. The long lead is the positive pin and the short lead will be the negative pin.
How can you tell if a led is positive or negative?
1, Looking down from the top of the LED there is usually a flattened edge, this identifies the negative pin of the LED. 2, If the LED is new, there will be one lead longer than the other. The long lead is the positive pin and the short lead will be the negative pin.
What happens to the light intensity of a led?
The light intensity of a LED does diminish gradually with time. This means that a LED has an operational life. This LED specification is of particular importance when a LED or LEDs are to be used for lighting applications. It is not normally as crucial when the LED is used as an indicator – here a catastrophic failure is of greater importance.
What’s the life expectancy of an LED light bulb?
They slowly dim over time. An LED’s rated life is therefore when the lamp is expected to be 30 percent dimmer than it was when brand new. Another key advantage LED’s have over traditional lighting is how long they last. There are LED bulbs that can replace a 4,000-hour halogen lamp and last up to 50,000 hours.
How is the colour of the light emitted by an led determined?
Therefore the colour of the light emitted by an LED is NOT determined by the colouring of the LED’s plastic body although these are slightly coloured to both enhance the light output and to indicate its colour when its not being illuminated by an electrical supply.
What kind of light is a blue light?
The chances are good that what you have observed is a “black light”, which can be either a fluorescent or incandescent bulb, coated to allow only the long-wave UV-A light and some blue and violet visible light pass through, or, an LED Blue Light.