Pulse shaping circuit and output waveform

Pulse shaping circuits are circuits that change the shape of an input waveform (for example clipping, clamping, differentiating, integrating) to produce a desired output waveform such as a pulse or square wave. Diode clippers and clampers and RC circuits are common examples.

Output of the given circuit

Assumptions (values were hard to read): Vin = 15 sin ωt, series resistor Rs = 2 kΩ, load RL = 1 kΩ, ideal diode in series with a 3 V battery in a shunt branch. The diode anode is on the output side, so it conducts when Vo exceeds +3 V.

 Vin o--[2k]--+----------+--o Vo
              |          |
              D         RL 1k
              |          |
             3 V         |
 GND o--------+----------+

Diode OFF (Vo < 3 V): the circuit is a voltage divider: Vo = Vin × RL/(Rs + RL) = Vin × 1/3 = Vin/3

The diode turns ON when Vin/3 = 3 V, that is Vin = 9 V.

Diode ON (Vin > 9 V): Vo is held at 3 V.

Negative half cycle: the diode stays OFF, Vo = Vin/3, so the negative peak is −15/3 = −5 V.

 Vo
 +3 V |    ______           ______    (clipped)
      |   /      \         /      \
   0  +--/--------\-------/--------\--
      |            \_____/
 -5 V |

Result: the positive peak is clipped flat at +3 V; the negative peak reaches −5 V (reduced by the divider).