Diodes

Meaning of Diodes

Diode is a device which only allows current to flow in one direction. A diode is a specialized electronic component with two electrodes called the anode and the cathode. Most diodes are made with semiconductor materials such as silicon, germanium, or selenium.

Types of diode

1.Fixed Diode

Fixed diode is a two-terminal electronic component that conducts primarily in one direction. The diode can be modeled as an ideal diode in series with a fixed resistor. In a small silicon diode operating at its rated currents emitting.

2.LED

Light Emitting Diode A transducer which converts electrical energy to light energy. A light-emitting diode (LED) is a two-lead semiconductor light source. It is a p–n junction diode, which emits light when activated. When a suitable voltage is applied to the leads, electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electro-luminescence, and the color of the light (corresponding to the energy of the photon) is determined by the energy band gap of the semiconductor.

3. Zener Diode

Normal diodes will also break down with a reverse voltage but the voltage and sharpness of the knee are not as well defined as for a Zener diode. Also normal diodes are not designed to operate in the breakdown region, but Zener diodes can reliably operate in this region.

4. Potodiode (LDR)

Photodiode is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the photodiode. A small amount of current is also produced when no light is present. Photodiodes may contain optical filters, built-in lenses, and may have large or small surface areas. Photodiodes usually have a slower response time as their surface area increases. The common, traditional solar cell used to generate electric solar power is a large area photodiode.

Diode symbols

Diode Symbols

Diode color code

Diode unit is voltage V