10 sec to 30 min Time Delay circuit with relay transistor | ElecCircuit.com
Alarm for Water Heater – Mohan's electronics blog
Amazon.com: EMDMAK Sand Timer Colorful Hourglass Sandglass Timer 1 min/3 mins/5 mins/10 mins/15 mins/30 mins Sand Clock Timer for Games Classroom Home Office(Pack of 6): Home & Kitchen
Set timer for 30 minutes 👍
1 Minute, 5 Minute, 10 Minute and 15 Minute Timer Circuit Diagram using IC 555