ultrasonic sensor with relay

Using Arduino Sensors
1

hi,
I am new to Arduino . i was trying to make ultrasonic sensor to work with relay , when object reaches at certain distance the sensor trigger relay . Is it possible to make it ?
Thanks

2

Yes, but usually you'll need a transistor to drive the relay

3

Could you tell us what kind of ultrasonic sensor you are using?
That way we can give better advise.

Regards
Jak24

4

Thanks for the reply , I am using hc-sr04 sensor .

5

A very little googling found this:
http://iteadstudio.com/application-note/arduino-ultrasonic-ranging-with-hc-sr04/