Maximum output current: 15 mA at a 5 V power supply (VPP > 50%), and at least 35 mA with a 12 V power supply (VPP > 50%). LED indication: The output includes an LED indicator. When the output is low, the LED is on; when the output is , the LED is off. At low frequency, the LED will flash. Duty cycle: The duty cycle can be finetuned. Duty cycle and frequency are not independently adjustable; changing the duty cycle will change the frequency. Output amplitude: 4.2 Vpp to 11.4 Vpp. The output amplitude depends on input voltage (4.2 Vpp with 5 V input, up to 11.4 Vpp with 12 V input). Main chip: N5555. Input DC 515 V. Output amplitude ranges from 4.2 Vpp (5 V input) to 11.4 Vpp (12 V input). Output frequency spans four selectable bands: 1 Hz50 Hz, 50 Hz1 kHz, 1 kHz10 kHz, and 10 kHz200 kHz. Applications: Electronics lab testing: generate controlled test signals for opamps, ADCs, and microcontroller timing experiments. Signal and driver testing: drive small signals into optocouplers, LEDs, or lowcurrent load demonstrations to verify response and timing. Education and prototyping: demonstrate how duty cycle affects frequency and explore different frequency bands for timing studies and signal experiments.