On Oct 23, 11:28*am, wrote:
I finished making my fox (and cat) scarer using one of those noisy impulse water sprinklers. This is controlled by a PIR which *activates a 12v solenoid valve connected to the garden hose that then connects to the sprinkler.

It works a real treat but the problem is that *solenoid slams shut instantaneously. This sends a shock wave back through the water system. And the result was that the shock waves caused a water leak at a junction of the incoming water supply from the street.

My question is to find out if there's an easy way to overcome the shock wave problem - either by:-
1. Electrical solution to close the solenoid progressively *- whilst still making it open instantly.
or
2. Some mechanical means in a pressure vessel or whatever?

All suggestions are welcome.

http://en.wikipedia.org/wiki/Water_h...ating_measures