The application of PLTS to public street lighting (PJU) is to provide lighting for road users at night. The problem with PJUs with PLTS is that if there is a problem with the battery which is the main source of electricity, it is necessary to have a switching system with a backup electricity source such as PLN. The formulation of the problem in the research is how to select the electricity source from the main source to the backup source by looking at the delay or time switch. The aim is to design PLTS as the main electricity source at PJUs with a PLN backup electricity source with automatic transfer switches. The research method used is quantitative, which prioritizes numerical data in the form of quantities that will later be processed. The data sources that will later be taken are in the form of voltage, cultural current on the PLTS and the time of movement seen on the ATS. Data collection techniques consist of conducting observations or testing to obtain data which will later be processed and research conclusions drawn. The research results of the ATS switching delay time are mainly sourced from PLN from the PLN electricity source to PLTS where 10 experiments were carried out and obtained an average time of 240.8 milliseconds and from PLTS to PLN 83.5 milliseconds. When the main source of switching delay is from PLTS, the switching time for PLTS to PLN is found to be an average of 241.2 milliseconds and from PLN to PLTS 83.7 milliseconds. Solar panel measurements obtained an average voltage value of 12.53 V and an average current value of 1.95 A. While battery measurements obtained an average voltage value of 15.52 V, an average current value of 1.84 A during the hours of 08.00 - 16.00