The amusing circuit of electronic candle was designed to react by blowing or giving a puff to a microphone, causing the bulb or LED to turn OFF like a normal candle.

This simple circuit aims to provide an indication of an appliance if it is ON or OFF with the use of green and red LEDs.

The circuit will provide a beeping sound to alarm the household that the refrigerator door has been opened for more than 20 seconds.

The circuit has been designed for loudspeakers to provide a monitoring scheme of audio power being supplied which will determine that any setup will not be required without the presence of a power supply.

The circuit was designed similarly with door bell units as it generates an audio of bells ringing with dual tones.

The circuit provides a means of repetitively alerting an individual jogger for a fixed amount of time that employs beeping as the indicator.

A temperature change is what this circuit is designed to detect to as it performs the function of a comparator.