Key benefits Flexible signal source for testing and small driving tasks: four selectable frequency bands and a wide input range let you use the module in 5 V and 12 V systems without extra converters. Predictable output amplitude and current that scale with supply voltage, so you can choose the supply that meets your load requirements. Visual output status via builtin LED makes troubleshooting and monitoring simple. Main specifications Main chip: N5555. Input: DC 5–15 V. Output amplitude (varies with supply): about 4.2 V V‑PP at 5 V input up to about 11.4 V V‑PP at 12 V input. Output frequency: four selectable ranges — 1 Hz–50 Hz, 50 Hz–1 kHz, 1 kHz–10 kHz, 10 kHz–200 kHz. Output current: approximately 15 mA with a 5 V supply; approximately 35 mA with a 12 V supply. (With V‑PP > 50% the module provides ≈15 mA at 5 V and ≥35 mA at 12 V; actual current depends on supply and load.) LED indicator behavior: LED is ON when output is low, OFF when output is ; at low frequencies the LED flashes. Performance and compatibility Works with common DC systems from 5 V to 15 V. Output amplitude and available current increase with higher supply voltage (examples given for 5 V and 12 V). Four frequency bands cover slow timing signals up to frequency test signals (up to 200 kHz). Suitable for driving small loads within the listed current limits; verify load current requirements against the module's output current at your chosen supply voltage. Practical use scenarios Signal generator for bench testing: produce adjustable squarewave signals across a wide frequency range to verify circuit response, trigger inputs, or test filters. Tone or alarm driver for small devices: generate audible tones or pulse patterns when used with appropriate transducers that stay within the module's current limits. Educational electronics and prototyping: quick source of selectablefrequency pulses for breadboard experiments, microcontroller input testing, and timing demonstrations. Notes and precautions Output amplitude and current depend on the input voltage; use a suitable power supply for your intended load. Confirm your driven device's current draw does not exceed the module's output capability at the supply voltage you choose. The LED provides a simple visual indication of output state and frequency behavior; it is not a substitute for a measurement instrument when precise waveform analysis is required.