Clampers

Electronic devices and circuit theory

1. C lampers Mateen chaudhary

2. clampers

3. clampers A network that shifts a waveform to a different level Does not change the appearance of the applied signal Time constant t=RC

4. Operation of clampers

5. clampers Positive clampers Shifts its input waveform in a positive direction lies above a dc reference voltage Negative clampers shifts its input waveform in a negative direction lies below a dc reference voltage

6. Positive clampers

7. Positive clampers In ideal case

8. clampers Clamping is not perfect since diode drops 0.7V. Negative peak

9. Working of positive clamper Negative half cycle Conduct and act as short circuit and Output v=0 Capacitor is charged to peak value and behave like battery Positive half cycle Does not conduct and act as open circuit Output voltage v o = v m +v m

10. Positive clamper

11. Negative clamper

12. Working of negative clampers Positive half cycle diode conducts and acts like a short circuit Capacitor is charged to peak value and behave like battery Output v=0 Negative half cycle diode is open and output can be found by applying KVL

13. Negative clamping v m - v m - v o =0 V o= - 2v m

14. Clamping networks

15. Application of clampers T est equipment R adar systems Sonar systems Electronic counter measure systems Used in TV receivers as a DC restorer