CASE #93: Hap Tells His Backyard Varmints to Hit the Road

Tired of torn-up flower beds, Hap took matters into his own hands by combining a sprinkler and wireless driveway alert system. To allow enough time for the sprinkler valve to open, build pressure, and activate the sprinkler head, he constructed a time-delay unit from an old standby 555 timer. It activates the sprinkler valve with ac power from the control for 10 to 12 seconds - allowing plenty of time to open and apply a good H₂O dousing to varmints and wayward mailmen alike. Scroll down to view a video demonstration and the parts list.