Diodes are two terminal electronic components, which allows the current to flow only through one direction, and blocks the flow from the opposite direction. When the diode allows the current to flow through it, it's called as Forward biased (F/W) and when it blocks the current, its called as reverse biased (R/V).
Types and applications of diodes:
1) In a wire, if we want a current to flow only in a single direction, and block the current from opposite direction, we use diodes.
For example, suppose there is a battery charging circuit. When the battery is being charged ,current flows from charger to the battery, and it gets charged. Now, if the charger is switched off from the external power source, and the battery is kept connected to the charger, current may flow from the battery to the charger and charger may consume some power from the battery. So, if we use a diode in between the wires, connected between the charger and the battery, such that the current flows only from charger to the battery and not from battery to the charger, we can remove the power loss due to reverse flow of current.
Further improvements in the DC output current can be done, by using filters (capacitors), inductors and multiple diode combinations.
3) Zener diodes are special type of diodes, which has its applications, mostly in reverse biased condition. When connected in forward bias, zener diode acts as a normal diode and current flows through it, but when its connected in reverse bias mode, it does not allow the current to flow, up to a certain value of voltage called "breakdown voltage". Zener diodes are available with a specified breakdown voltage.When the breakdown voltage is reached, zener diode starts flowing even in reverse biased condition.This property of the zener diodes can be used as a voltage regulator.
For example, suppose there is a device with working voltage of 5 Volts. We connect a 5 Volt power source to the device. Now , we connect a zener diode with 5-Volt specification, in parallel to the device. Now, the zener diode will block the current through it, up to 5 volts and let the device work. Now, If the voltage increases to more than 5 volts, zener diode will start flowing all the current (short-circuit) ,as it will cross the breakdown voltage. In this way, all the current flows through the zener diode, and the device is not damaged.
4) Light Emitting Diodes (LEDs) are special type of diodes, which emits light when a small current flows through it. It emits light only when connected in forward bias. Led consumes very less power, and hence they are used widely.
1) In a wire, if we want a current to flow only in a single direction, and block the current from opposite direction, we use diodes.
For example, suppose there is a battery charging circuit. When the battery is being charged ,current flows from charger to the battery, and it gets charged. Now, if the charger is switched off from the external power source, and the battery is kept connected to the charger, current may flow from the battery to the charger and charger may consume some power from the battery. So, if we use a diode in between the wires, connected between the charger and the battery, such that the current flows only from charger to the battery and not from battery to the charger, we can remove the power loss due to reverse flow of current.
2) Diodes can be used as a rectifier, which converts an alternating current to a DC current
3) Zener diodes are special type of diodes, which has its applications, mostly in reverse biased condition. When connected in forward bias, zener diode acts as a normal diode and current flows through it, but when its connected in reverse bias mode, it does not allow the current to flow, up to a certain value of voltage called "breakdown voltage". Zener diodes are available with a specified breakdown voltage.When the breakdown voltage is reached, zener diode starts flowing even in reverse biased condition.This property of the zener diodes can be used as a voltage regulator.
For example, suppose there is a device with working voltage of 5 Volts. We connect a 5 Volt power source to the device. Now , we connect a zener diode with 5-Volt specification, in parallel to the device. Now, the zener diode will block the current through it, up to 5 volts and let the device work. Now, If the voltage increases to more than 5 volts, zener diode will start flowing all the current (short-circuit) ,as it will cross the breakdown voltage. In this way, all the current flows through the zener diode, and the device is not damaged.
4) Light Emitting Diodes (LEDs) are special type of diodes, which emits light when a small current flows through it. It emits light only when connected in forward bias. Led consumes very less power, and hence they are used widely.
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