E255-5D-W15L L1 Activity 1 by Teo Chee Seng (RP) https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0 Q1: Discuss and explain the temperature effects on the forward and reverse characteristics of a diode. Q2. List the different types of diodes and which diode parameters you will need to consider for such applications. en-us 2023-10-19 07:40:49 UTC 2023-10-20 03:56:17 UTC hello@padlet.com Team 1 https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755621603 Q1) Increase temperature, increase thermal activity, decrease diode resistance. Forward diode – If forward current flow greater than its maximum allowable rating, the diode will break down from excessive heat. If there reverse current / leakage current occurs the temperature will increase and cause breakdown and permanent damage to the diode. Some diodes, like Zener diodes and avalanche diodes, are specifically designed to exhibit a controlled breakdown behaviour in the reverse-biased region. Temperature can affect the sharpness and stability of this breakdown voltage. 
 
Q2) Light emitting diode- emits light. Most LEDs requires a forward voltage of 1.2 to 3.5V before any amount of current can flow through it. And it also must be connected in series with a current limiting resistor to limit the current within the desired value of 10-30mA. 
]]> 2023-10-20 03:36:43 UTC https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755621603 Team 3 https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755622346 Q1) As temperature increases, the forward voltage drop (Vf) of a diode typically decreases slightly. This is due to the temperature dependence of the thermal voltage (Vt). The thermal voltage (Vt) is approximately 26 mV at room temperature (around 300 K), but it increases with temperature. Therefore, as the temperature rises, Vt also increases, causing a small decrease in Vf for a given forward current.

Q2)  Light Emitting Diode

Parameters:

·      Forward Voltage (Vf)
·      Forward Current (If)
·      Wavelength (λ)
·      Luminous Intensity (Iv)


]]> 2023-10-20 03:37:24 UTC https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755622346 Team 4 https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755622433 Q1 As the temperature increases on forward bias the forward voltage drop of a diode typically decreases slightly. As the thermal voltage depends on temperature. Thus, as temperature increases thermal voltage also increases causing a small decrease in voltage drop for a given forward current.  
As temperature rises, the reverse leakage current of a diode also increases. This is mainly due to the production of charge carriers within the diode caused by heat, resulting in a greater flow of current in the opposite direction. 
 
Q2  
Light Emitting Diode (LED): 
Parameters: 
  • Forward Voltage (Vf) 
  • Forward Current (If) 
  • Wavelength (λ) 
  • Luminous Intensity (Iv) 
 
Zener Diodes: 
Parameters:  
  • Zener voltage (Vz) 
  • tolerance (±%) 
  • Zener test current (Iz) 
  • maximum power dissipation (Pd) 
  • temperature coefficient 
  • reverse leakage current. 
 
Avalanche Diodes: 
Parameters:  
  • Avalanche breakdown voltage (VBR) 
  • reverse leakage current (Ir) 
  • forward current rating (If) 
  • maximum surge current 
  • junction temperature 
]]> 2023-10-20 03:37:29 UTC https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755622433 Team 5 https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755623913 Q1. For forward characteristics, as the temperature increases, the vf drop of a diode decreases slightly. Because the temperature depends on the Vt. The Vt is approximately 26 mV at room temperature (around 300 K), but it increases with temperature. So, when the temperature rises, Vt also increases, causing a small decrease in Vf for a given forward current.

      For reverse characteristics, Ireverse, the in reverse bias region, the temperature affects the reverse characteristics of a diode. But when at higher temperatures, the Ireverse increases. This is because of the increase in the number of thermally generated charge carriers.

 

Q2. Light Emitting Diode :

Parameters:

·       Forward Voltage (Vf)
·       Forward Current (If)
·       Wavelength (λ)
·       Luminous Intensity (Iv)
 
Zener Diodes:

Parameters: 

·       Zener voltage (Vz)
·       tolerance (±%)
·       Zener test current (Iz)
·       maximum power dissipation (Pd)
·       temperature coefficient
·       reverse leakage current.
 
Avalanche Diodes:

Parameters: 

·       Avalanche breakdown voltage (VBR)
·       reverse leakage current (Ir)
·       forward current rating (If)
·       maximum surge current
·       junction temperature


Activity 2

·       To check if its faulty or shorted diode, the needle will deflect to the left (towards zero or close to zero), it means the diode is shorted and faulty or both. In this case, current flows in both directions.
 

·       2. An analogue multimeter uses a needle that moves along a scale to indicate the value of the measurement whereas a digital multimeter uses a numeric display to show the exact value of the measurement.


]]> 2023-10-20 03:38:37 UTC https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755623913 Team 2 220359231 https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755624403 Q1: Temperature impacts diode characteristics in forward and reverse bias modes, causing thermal runaway and affecting breakdown voltage. Engineers must account for these effects in circuit design for diode reliability.

Q2: Zener diode, photodiode, Tunnel diode, Laser diode, PIN diode]]> 2023-10-20 03:39:03 UTC https://padlet.com/teo_chee_seng1/rqhi5evfpab8rut0/wish/2755624403