A pilot demystifies the "ding" sound heard on airplanes. It's not an alarm, but a signal for the crew. One ding signifies takeoff clearance, another at 10,000 feet allows cabin service to begin, and ...

This is a simple and very useful article on building a circuit that produces “ding dong” sound using 555 timer. We observe different types of door bells in different houses. They produce different ...

This simple and cost-effective ding dong electronic doorbell circuit is based on IC 8021-2. The IC has an in-built circuitry to produce ding dong sound each time its pin 3 is pulled low. The sound is ...