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If the semiconductor has a few per million atomswith FIVE outermost (valence) electrons ....
... FIVE valence atoms have an “extra” electron in the crystal structure.
The “extra” electron is NEGATIVELY charged.
Semiconductors
This is Called “N-TYPE”
If external voltage is applied:
Junction Diode
NEGATIVE to ANODE; POSITIVE to Cathode
The Depletion (Barrier) Zone is increased,BLOCKING CONDUCTION
Rectifier Filters
Moderate Load ....
Capacitor charges to Peak value as voltage rises,but discharges when voltage drops away.
Single-Phase Full-WaveBridge Rectifier
Back
Conduction DuringNegative ½ Cycle
Three-Phase Waveforms3-phase AC Features
Phase Voltages are 1200 out-of-phase
1200
2400
Three-Phase Half-Wave Rectifier
(Animated)
Three-Phase Half-Wave Rectifier
Maximum value = VPeak Minimum value = VPeakx0.5
VRipple = VPeak – (VPeak x 0.5) = VPeak x 0.5
Three-Phase Full-Wave Rectifier
Maximum value = VPeak Minimum value = VPeakx0.866
VRipple = VPeak – (VPeak x 0.866) = VPeak x 0.134
Voltage Regulator
THREE-TERMINAL REGULATOR(7xxx Series)
7812
Input
Output
Ground
Positive Output
7812
Regulated Voltage (12V)
Voltage Regulator
THREE-TERMINAL REGULATOR(7xxx Series)
7912
Input
OutputGro
und
7912
Regulated Voltage (12V)
Negative Output
Electronic Control Devices (Thyristors)
Silicon Controlled Rectifier (SCR)
Varying R1 varies charging rate of the Capacitor.
Animated
This varies the Trigger Point, controlling the average load current
Trigger Point can be delayed up to nearly 1800
Electronic Control Devices (Thyristors)TRIAC
Waveform across Load Waveform across TRIAC