Photovoltaic (PV) simulators are fundamental tools for the operational evaluation of PV energy production system components (e.g. battery chargers, DC/AC inverters, etc.), in order to avoid time-consuming and expensive field-testing process. A universal Transistor-based hardware SIMulator of photovoltaic panels or a generator in operation, named TSIM, is presented in this paper. TSIM was developed for accurate reproduction of the electrical behavior of photovoltaic (PV) systems made of various types of panels considering possible uniform or partially illumination, the last one being due or not to shadows. TSIM is dedicated for simulation and to perform various tests of a complete PV installation under various operating and environmental conditions. It is useful for power electronics designers and researchers who need an efficient and straightforward way to model and simulate photovoltaic arrays. In this contribution, software simulation results obtained under OrcCAD environment validate the original transistor-based model of PV panels. TSIM hardware prototype is then described, experimented and tested. For validation and illustration, in the experimental part of this work, TSIM prototype was sized for the hardware simulation of a marketed panel of 175 W-peak power constituted by three strings of cells. TSIM performances and efficiency were validated by comparison of the characterizations of the panel behavior in actual experimental conditions and the simulation results obtained by TSIM under various illumination and input powers. TSIM faithfully reproduces the I–V characteristics of the panel for various configurations of shadowing.