Identify create electrons and holes. It can also be

Identify the types of diodes.PN Junction DiodeThe one of the simplest semiconductor devices that works as a switch. It has a characteristic of passing current in only one direction only. Applying positive voltage (forward bias), it can supply free electrons and holes that allows current to flow through pn junction that represents close switch. Applying negative voltage(reverse bias) results in free charges being pulled away from junction resulting in depletion layer width increase that prevents current to flow representing an open switch. Zenner DiodeIt usually conduct with reverse current. In forward bias, Zener diode works as a normal diode. In reverse bias and when its reverse current in increase to rayed value, the voltage drop across the diode becomes steady. Light Emitting DiodesIs a P-N junction diode which emits light when turned ON. It is unidirectional and have a forward voltage rating to light it up. PhotodiodeWhen PN junction detects light, it can create electrons and holes. It can also be used to produce electricity. Schottky DiodeIt is formed by metal-semiconductor junction that has a lower forward voltage drop which gives fast switching speed used for dc-dc converter.  Varactor DiodeIts P-N junction capacitance can be altered with an applied reverse voltage. The P and N type region in diode acts as a charged plates and depletion region as dielectric or insulator. It is also known as Varicap/ Variable capacitance diode/ Tuning diode. Step Recovery DiodeIs a type of microwave diode used to generate pulses at very high frequency. PIN DiodeIt has P-type and N-type regions but it has no doping. The region of intrinsic semiconductor has the effect of increasing the area of depletion region use for switching applications. Tunnel DiodeUsed for microwave applications because it is capable for very fast operation made possible by the use of quantum mechanical effect. Backward Diode It is a form of tunnel diode where one sided of the junction is heavily doped than the other.  Discuss, illustrate and derive the related equation of various rectifier circuits. Half -wave RectifierThe power diode passes one half of each complete sine wave of ac supply in order to convert it into pulsating dc supply. During positive region, the diode conducts and allows current to flow to supply the load. During negative region, diode blocks the current that can consider as open circuit.  During positive regionv_i-0.7-v_o=0v_o=v_i-0.7 During negative regionv_o=0 Full-wave Bridge RectifierIt is a single phase rectifier that uses four diodes connected in a closed loop “bridge” that outputs a pulsating dc. During positive region, 2 diode is on while the other 2 is off and those 2 diode allows current to flow to supply the load. During negative region, 2 diode is on and the other 2 is off  and those 2 diode allows current to flow to supply the load. During the positive region  v_i-0.7-v_o-0.7=0v_o=v_i-1.4During the negative cycle  -v_i+0.7+v_o+0.7=0v_o=v_i-1.4Input and output waveforms  Center-tapped Full wave RectifierIt is consist of two power diodes connected to a load. During positive region, diode 1 allows current to flow to supply the load. During negative region, diode 2 allows current to flow to supply the load. During positive region  v_i-0.7-v_o=0v_o=v_i-0.7During negative region  v_i-0.7-v_o=0v_o=v_i-0.7Discuss the block diagram of a power supply. You may illustrate it and the corresponding waveformsBlock diagram of a power supply In the given block diagram above, in a basic power supply, the primary winding is connected to the main supply; while, the secondary winding is used to obtain an AC voltage suitable to drive the circuit. After it, is the rectifier stage. In this stage, it converts AC to DC which flows in one direction. There are three types of rectifier circuits namely half wave, full wave, and bridge rectification. For the half wave rectification, it only conducts on one half cycle of the AC input. As the amplitude of the half cycle for which the diode conducts, it will be reduced by approximately 0.7 V due to the voltage drop across the silicon diode. For full wave rectification, it uses two silicon diodes, each of these outputs is half waved rectified, producing two pulses of current every cycle. The output frequency, therefore, produces twice the input frequency. Lastly, the bridge rectifier, uses four diodes arranged in a bridge circuit. In power supplies, capacitors are placed to filter the pulsating DC output after rectification. In this way, nearly constant DC voltage is supplied in the load connected. The regulator provides a stable DC voltage regardless of the load. This maintains a constant voltage level.State other applications of a diode.(rectifier circuit is an application of diode) Power Conversion Demodulation of Signals Over-Voltage Protections Current Steering Clippers Clampers Voltage Multiplier Protective Configurations Controlled Battery- Powered Backup Polarity Detector Displays(LED) Square- Wave generator AC Regulator