Diode Oscilloscope Simulator
Observe how a diode changes an AC sine-wave signal into a half-wave rectified waveform.
1. Diode Circuit
During the positive half-cycle, the diode becomes forward biased and current flows. During the negative half-cycle, the diode is reverse biased and blocks current.
2. Oscilloscope Controls
3. Oscilloscope Display
4. What You Are Seeing
The yellow waveform represents the AC input voltage. It is a normal sine wave containing both positive and negative half-cycles.
The green waveform represents the voltage across the resistor after the diode.
When the input voltage is positive and greater than the diode’s forward voltage, the diode conducts.
When the input becomes negative, the diode switches OFF and approximately zero voltage appears across the resistor.
If Vin > VD:
Vout = Vin − VD
If Vin ≤ VD:
Vout ≈ 0 V
Diode current:
I = Vout / R
5. Example
Suppose the input is a 5 V peak sine wave and we use a
silicon diode with approximately 0.7 V forward voltage.
Maximum output voltage:
Vout = 5 − 0.7 = 4.3 V
With a 1 kΩ resistor:
I = 4.3 / 1000 = 4.3 mA
Therefore, the oscilloscope shows the positive half of the sine
wave while the negative half is blocked.