Waveforms generated in UJT relaxation oscillator circuit due to additional involvement of external resistances in series
What kind of waveforms are generated in UJT relaxation oscillator circuit due to additional involvement of external resistances in series configuration with the provision of corresponding base terminals ?
a. Square waveforms
b. Triangular waveforms
c. Saw-tooth waveforms
d. Spike waveforms
Correct Answer: d. Spike waveforms
Relaxation oscillator basically comprises UJT and a capacitor that gets charged through resistance by switching ON VBB .
UJT fires when capacitor voltage reaches to the value of peak voltage in time 'ts' & immediately discharges till the voltage value decreases to lowermost value (Vv),
As a result, the device gets turned off and the capacitor begins to charge again and hence it leads to the repetition of cycle ceaselessly by generating sawtooth waveform across the capacitor.
In addition to this, the involvement of external resistances connected serially in the circuit results in the generation of spike waveforms despite of sawtooth, square or triangular ones.