A great example is this simple wireless AC current detector ... which lights an LED. The whole circuit is built on top of a battery clip so it can be run straight from the top of a standard ...

setting off our alarm! Practise drawing the following series circuits using symbols: A simple circuit with a bulb and battery. A series circuit where the bulb doesn't light up. A circuit with ...

Ionization smoke alarms use a battery and two metal plates, called electrodes, to create an electrical circuit ... or wireless smoke alarm systems.” Simple wireless smoke detectors, like ...