In the Power Electronics Laboratory at the Department of Electric Machines, Drives and Automation, FCRO4100 firing board to control single-phase and FCOG6100 to control three-phase thyristor rectifiers are used. In this master's thesis, complete documentation is created which explains the principle of firing circuit boards and describes the individual subsystems that relates to the boards. For the purpose of master’s thesis, control devices for thyristor rectifiers have been developed. Created devices control the FCRO4100 and FCOG6100 firing boards. For the purpose of displaying the delay angle, an electronic board was created. Depending on the change in the delay gate signal, this electronic board calculates the delay angle of the thyristor rectifier and using a digital meter displays it on the screen located on the front panel of the thyristor rectifier devices. To enable the display of the delay angle of firing boards, modifications of the electronics of the certain subcircuits have been made on the FCRO4100 firing boards. The devices are built into the laboratory desks. In order to test the correctness of the created devices, measurements were performed in the laboratory using single-phase and three-phase thyristor rectifiers. Prior to the measurement, simulations were made using Plecs software package, which describe the control using the firing circuits boards. Based on simulation and measurement results, a proposal for laboratory exercises that could be carried out from the course Power Electronics at the Faculty of Electrical Engineering and Computing are given.