Did you know ? LED stands for light-emitting diodes !
LEDs stands for light-emitting diodes.
LEDs convert electrical energy into visible light.
This is an electronic symbol for a light-emitting diode:
Watch out – LEDs are polarized!
Light-emitting diodes (LEDs) are polarized. This means that they only allow current to flow in one direction.
Because of this, you need to pay attention to how you are going to place your LED in the electronic circuit.
The tiny metal legs of every LED are not the same length. They mark polarity!
The positive leg is longer (we call this one the anode), and the shorter one is negative (this one has a funny name – cathode).
Electrical energy flows from the anode to the cathode and not in the opposite direction.
If you put the LED in the wrong way, it won’t light up because the electrical energy will not be able to flow through it.
Resistors and LEDs make a great team!
LEDs can be damaged if they receive too much energy.
But don’t worry, we sent resistors to the rescue!
Resistors will limit the amount of electrical energy flowing through the circuit and
save your LEDs from getting damaged.
Historical fun facts:
A Russian inventor Oleg Vladimirovich Losev made the first LED in 1927.
Oleg Vladimirovich Losev (10 May 1903 – 22 January 1942) was a Russian scientist and inventor who made significant discoveries in the field of semiconductor junctions and the light emitting diode (LED).
Although he was never able to complete a formal education and never held a research position, Losev conducted some of the earliest research into semiconductors, publishing 43 papers and receiving 16 “author’s certificates” (the Soviet version of patents) for his discoveries.He observed light emission from carborundum point-contact junctions, constructing a light-emitting diode (LED), did the first research on them, proposed the first correct theory of how they worked, and used them in practical applications such as electroluminescence. He explored negative resistance in semiconductor junctions, and was first to use them practically for amplification, building the first solid-state amplifiers, electronic oscillators, and superheterodyne radio receivers, 25 years before the invention of the transistor. However his achievements were overlooked, and languished unknown for half a century before being recognized in the late 20th and early 21st century.
LEDs have many advantages over incandescent light sources, including lower power consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. In exchange for these generally favorable attributes, disadvantages of LEDs include electrical limitations to low voltage and generally to DC (not AC) power, inability to provide steady illumination from a pulsing DC or an AC electrical supply source, and lesser maximum operating temperature and storage temperature. In contrast to LEDs, incandescent lamps can be made to intrinsically run at virtually any supply voltage, can utilize either AC or DC current interchangeably, and will provide steady illumination when powered by AC or pulsing DC even at a frequency as low as 50 Hz. LEDs usually need electronic support components to function, while an incandescent bulb can and usually does operate directly from an unregulated DC or AC power source.
Did you know?
LED lightbulbs are the most efficient type of lightbulbs.
Unlike “regular” “old” bulbs (we call these incandescent lightbulbs), which release 90% of their energy as heat, LEDs use energy far more efficiently with very little wasted heat.