Product description What it does - Uses an IC555 timer as the oscillator core. The circuit generates audible tones whose pitch is set by resistor selections. - Resistors R2–R9 select the oscillation frequency. Together with R1, capacitor C2, and the IC555, the circuit produces eight distinct oscillation frequencies. - The “scale circle” arrangement maps those frequencies to different keys so that pressing different keys yields different musical scales—suitable for simple electronic piano implementations or tone-generating modules. Key benefits — why you need it - Predictable tone selection: Fixed resistor choices (R2–R9 with R1 and C2) produce eight reliable, repeatable frequencies for consistent pitch output. - Simple integration: Based on the widely used IC555 timer architecture, the circuit is straightforward to incorporate into hobby and educational projects that require selectable tones. - Easy to operate: Different keys directly select different resistors/frequencies, enabling intuitive play and quick testing without complex programming or tuning. - Educational value: Demonstrates fundamental electronics principles—oscillation, RC timing, and frequency selection—making it useful for learning and teaching. Important attributes - Function: Tone generation via an IC555 oscillator; eight selectable pitch outputs controlled by R2–R9 in conjunction with R1 and C2. - Compatibility: Designed around the standard IC555 timer concept and intended for use in 555-based tone generator or electronic piano circuits. - Performance: Produces eight distinct oscillation frequencies determined by the resistor network and timing capacitor; performance depends on the chosen resistor and capacitor values and the IC555 configuration. - Operability: Keys or switches select the corresponding resistor to change the oscillator frequency and therefore the emitted tone. Typical applications / use scenarios - DIY electronic piano or keyboard: Implement the scale circle so each key selects a resistor (R2–R9) to play different notes using the IC555 oscillator. - Electronics education and labs: Use the circuit to teach RC timing, oscillator behavior, and how component values affect frequency. - Small sound-effect generators: Integrate the module into hobby projects that need several fixed tones for alerts, chimes, or signaling. What to expect in practice - Eight selectable tones mapped to keys or switches. - Tone frequency determined by the resistor selected (R2–R9) in combination with R1, C2, and the IC555. - Straightforward wiring and predictable behavior consistent with standard 555 timer oscillator circuits. No additional specifications are altered: the described functions and components (IC555, R1, R2–R9, C2) and the eight-frequency operation remain as stated.