Product: Scale Circle (IC555-based tone generator) Key benefits - Produces clear, selectable musical tones for electronic piano/keyboard projects. - Provides eight distinct frequencies (tones) selectable via resistor network, enabling simple scale/key selection. - Uses a standard IC555 oscillator design for predictable, easy-to-understand operation and straightforward integration. How it solves problems - Replaces complex tone-generation circuitry with a simple resistor-selection approach, reducing design complexity. - Makes it easy to switch between pitches without reconfiguring the oscillator: change the selected resistor (R2–R9) to change pitch. - Supports prototyping, repair, and educational use where reliable, repeatable tone generation is required. How it works (operating principle) - The circuit uses an IC555 configured as an oscillator. The timing network includes resistors R1 and R2–R9 and capacitor C2. - Resistors R2–R9 are the selectable frequency elements; selecting a different resistor changes the total resistance seen by the IC555 timing network and therefore changes the oscillation frequency. - Together, R1, the selected resistor (one of R2–R9), and C2 produce eight discrete oscillation frequencies that correspond to different musical pitches or scale steps. Features and attributes - Function: Eight-step tone generation for electronic piano/keyboard use. - Compatibility: Designed for IC555-based oscillator circuits and for use in electronic piano/keyboard projects, DIY electronics, and educational experiments. - Performance: Eight distinct, selectable oscillation frequencies determined by the resistor network and the IC555 timing components. - Components: Uses resistors R1 and R2–R9, capacitor C2, and IC555 as the core timing/oscillator elements. - Operation: Tone selection is achieved by selecting one of the resistors R2–R9 to change pitch. Practical applications / use scenarios - DIY electronic keyboard: Implement selectable key tones in a hobbyist keyboard or simple electronic piano project. - Educational electronics: Demonstrate oscillator timing, RC networks, and how resistance affects frequency using a hands-on circuit. - Repair or prototyping: Replace or prototype tone-generation sections of small electronic musical instruments that use IC555 oscillators. Notes for users - Tone selection is performed by switching which resistor (R2–R9) is placed into the timing network with R1 and C2. - The module relies on the IC555 oscillator principle; ensure correct IC555 wiring and component connections when integrating. - No additional specifications (voltage, enclosure, pinout) are changed from the described component-level design; follow standard IC555 circuit practices when using this scale circle.