A portable function signal source designed specifically for teaching, competition, and maintenance workstations, capable of simultaneously outputting sine, square, triangular, sawtooth, pulse, and any waveform within the range of 1 Hz to 5 MHz, and visually demonstrating the impact of signal parameter changes (frequency, amplitude, duty cycle, phase) on circuit behavior. Typical applications: University analog/digital electrical experiments to verify the amplitude frequency characteristics of filters and trigger synchronization of oscilloscopes; In STEM classrooms for primary and secondary schools, use headphones and LEDs to visually observe frequency changes; Quick diagnosis for maintenance, providing standard excitation sources for amplifiers, speakers, and sensors.