[en] The authors describe large-signal klystron simulations using the particle-in-cell code KLSC. This code uses the induced-current model to describe the steady-state cavity modulations and resulting rf fields, and advances the space-charge fields through maxwell's equations. In this paper, an eight-cavity, high-power S-band klystron simulation is used to highlight various aspects of this simulation technique. In particular, there are specific issues associated with modeling the input cavity, the gain circuit, and the large-signal circuit (including the output cavities), that have to be treated carefully