Engineering Logbook
Unit 19: Diodes
Hazard: something that can cause harm
Risk: the chance (high/low); that any hazard will actually cause somebody harm
PPE: Personal Protective Equipment
Ohm’s Law states that current (I) is directly proportional to the voltage (V).
Current= Voltage/Resistance
Figure 1
Biased: to show an unreasonable preference based on your own opinion
Semiconductor: A semiconductor is something usually compromised of silicon, which
conducts electricity more than an insulator.
P-N Junction: A p-n junction is a diode that has two terminals/electrodes (cathode and
anode), which allows the electric current to flow in one direction whilst blocking the electric
current in the opposite direction
Forward Bias allows the electric current to flow
Reverse Bias blocks the flow of the electric current
Diode: Diode allows current flow in one direction only (left to right)
Figure 2
Zener Diode: Regulates and stabilises the voltage and they also work in reverse
biased.
, Engineering Logbook
Schottky Diode: Schottky diode is a diode with a low voltage drop
Tunnel Diode: The tunnelling diode has effectively negative resistance
Light Emitting Diode (LED): LED emits light when current flows through
Figure 3
Photodiode: Photodiode allows current flow when exposed to light
Active Components deliver/produce energy or power in the form of a voltage or a current
examples of active components are diodes, transistors, SCR and integrated circuits.
Passive Components utilize/store energy in the form of voltage or current, examples of
passive components are resistors, capacitor and an inductor.
Forward Biased Diode
This forward biased diode is working in this circuit like a closed switch allowing the current
to flow through itself, it also decreases the resistance. The current is allowed to pass
through the pn junction. But one requirement to forward-bias a diode is that the negative
side of the external bias voltage must be connected to the cathode or n region of the diode
and the positive side of the external bias voltage to the anode or the p region.
Figure 4
Unit 19: Diodes
Hazard: something that can cause harm
Risk: the chance (high/low); that any hazard will actually cause somebody harm
PPE: Personal Protective Equipment
Ohm’s Law states that current (I) is directly proportional to the voltage (V).
Current= Voltage/Resistance
Figure 1
Biased: to show an unreasonable preference based on your own opinion
Semiconductor: A semiconductor is something usually compromised of silicon, which
conducts electricity more than an insulator.
P-N Junction: A p-n junction is a diode that has two terminals/electrodes (cathode and
anode), which allows the electric current to flow in one direction whilst blocking the electric
current in the opposite direction
Forward Bias allows the electric current to flow
Reverse Bias blocks the flow of the electric current
Diode: Diode allows current flow in one direction only (left to right)
Figure 2
Zener Diode: Regulates and stabilises the voltage and they also work in reverse
biased.
, Engineering Logbook
Schottky Diode: Schottky diode is a diode with a low voltage drop
Tunnel Diode: The tunnelling diode has effectively negative resistance
Light Emitting Diode (LED): LED emits light when current flows through
Figure 3
Photodiode: Photodiode allows current flow when exposed to light
Active Components deliver/produce energy or power in the form of a voltage or a current
examples of active components are diodes, transistors, SCR and integrated circuits.
Passive Components utilize/store energy in the form of voltage or current, examples of
passive components are resistors, capacitor and an inductor.
Forward Biased Diode
This forward biased diode is working in this circuit like a closed switch allowing the current
to flow through itself, it also decreases the resistance. The current is allowed to pass
through the pn junction. But one requirement to forward-bias a diode is that the negative
side of the external bias voltage must be connected to the cathode or n region of the diode
and the positive side of the external bias voltage to the anode or the p region.
Figure 4
