Kitronik 555 Timer Astable (Tone Generator) Kit Description This kit is perfect for GCSE students needing to use a 555 timer in its astable mode, where it produces a square wave output. The frequency of which is adjustable via the variable resistor. The board has a choice of two outputs. The logic output can be used to drive another IC or a speaker can be connected so the tone is heard (e.g. a https://elecena.pl/product/19046575/555-timer-astable-tone-generator-kit 2021-07-12 https://elecena.pl/product/19046575/555-timer-astable-tone-generator-kit 2025-07-09