Oscilloscope

Sweep generator

t

TIME/DIVSweep

Trigger Fault

Trigger Fault

Trigger

Sawtooth

Trigger generation

Trigger

Sawtooth

Positive trigger level

Trigger

Sawtooth

Negative trigger level

Trigger

Sawtooth

Part of the signal: less than one period

Hold-on time

Trigger

Sawtooth

Part of the signal: more than one period

Dual Trace oscilloscope

• Use a single-beam (one electron gun) .• Time-multiplex the inputs.

– Chop mode or Alternate mode.• Chopped mode: during the same sweep

period, alternate between the two input signals. (better for slow sweep, i.e. high period)

• Alternate mode: one sweep period for each signal. ( better for fast sweep, i.e. low period)

X-Y mode

X

Y

Vy =A sin(𝝎 t)Vx =A sin (𝝎 t+θ)