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 door bell). The push button switch connects to the reset line such that the IC is only active when the button is pressed.

Requires x3 AA batteries and depending upon desired use a speaker, both available separately.