Photovoltaic panels are widely used energy converters. The direct conversion of solar radiation into electricity is an important contribution to the energy transition. In simple terms, a commercial solar system consists of solar modules, an inverter, cables, and, if necessary, a storage unit. A photovoltaic system cannot be operated without an inverter. In this work, the variable load to the panel in whole range between idling and short circuit is performed by a specially designed circuit. A central point of the inverter is to find the operating point, which depends on both the irradiance and the panel temperature, at which the highest power can be drawn from the panel, by forming the current/voltage characteristic curve. Due to the external parameters, this is constantly changing. With the designed circuit, it is possible to specify the changing current by means of a triangle generator and to automatically display the characteristic curve with the given influences. The values of the triangular oscillation of the current and the voltage following the current are transferred to the software, ¿Dewesoft7¿, in the microsecond range via the data acquisition device NI USB-6009 connected to the computer. By means of the data, a direct on-line graphical representation of the current and voltage curves as well as the characteristic curve is possible. The resulting power and the maximum power point can be read out directly. Furthermore, the temperatures of the ambient air and the panel are measured and displayed.