1. Semiconductors
If the semiconductor has a few per million atoms with FIVE outermost (valence) electrons ....
The “extra” electron is NEGATIVELY charged.
... FIVE valence atoms have an “extra” electron in the crystal structure.
This is Called “N-TYPE”

2. Junction Diode If external voltage is applied:
NEGATIVE to ANODE; POSITIVE to Cathode
The Depletion (Barrier) Zone is increased, BLOCKING CONDUCTION

3. Rectifier Filters Moderate Load ....
Capacitor charges to Peak value as voltage rises, but discharges when voltage drops away.

4. Single-Phase Full-Wave Bridge Rectifier
Conduction During
Negative ½ Cycle
Back

5. Three-Phase Waveforms
3-phase AC Features
2400
1200
Phase Voltages are 1200 out-of-phase

6. Three-Phase Half-Wave Rectifier
(Animated)

7. Three-Phase Half-Wave Rectifier
VRipple = VPeak – (VPeak x 0.5) = VPeak x 0.5
Maximum value = VPeak
Minimum value = VPeakx0.5

8. Three-Phase Full-Wave Rectifier
VRipple = VPeak – (VPeak x 0.866) = VPeak x 0.134
Maximum value = VPeak
Minimum value = VPeakx0.866

9. THREE-TERMINAL REGULATOR
Voltage Regulator
THREE-TERMINAL REGULATOR
(7xxx Series)
Positive Output
7812
7812
Input
Output
Ground
Regulated Voltage (12V)

10. THREE-TERMINAL REGULATOR
Voltage Regulator
THREE-TERMINAL REGULATOR
(7xxx Series)
Negative Output
7912
7912
Ground
Regulated Voltage (12V)
Input
Output

11. Electronic Control Devices (Thyristors)
Silicon Controlled Rectifier (SCR)
Varying R1 varies charging rate of the Capacitor.
This varies the Trigger Point, controlling the average load current
Trigger Point can be delayed up to nearly 1800
Animated

12. Electronic Control Devices (Thyristors)
TRIAC
Waveform across Load
Waveform across TRIAC