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

By: 
November 06, 2006

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 H 2O dousing to varmints and wayward mailmen alike. Scroll down to view a video demonstration and the parts list .

Timer Delay Circuit for Motion Detection System
Amt Part Description Allied Part #
1 555 Timer IC 263-0133
2 1N4004 Diodes 266-0004
1 Green LED 670-1199
1 Yellow LED 670-1066
1 SPST Mini Switch 642-1136
1 5V dc DPST Relay 886-2529
1 25K potentiometer 754-1257
1 470 ufd Capacitor 852-6566
1 5 ufd Capacitor 507-1056
1 10 ohm Resistor 296-6400
2 100 ohm Resistor 296-5644
2 1 Kohm Resistor 296-5562
1 15 Kohm Resistor 296-5720
1 Terminal Strip 607-7058
Additional parts required: Reporter Wireless Alert System with (1) Transmitter and (1) Receiver; Optima Sprinkler Control Panel
Download Hap's instructions . (PDF)

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