Motor triggered by a vibration sensor

[pebe]

Your 12V 1A motor will probably take up to 5A when starting up from rest. The contacts of the Panasonic NF2EB are only rated at 2A. They may be adequate but this Omron G2RL-2-12DC is rated at 8A, so would be a better one.

[julienfhd]

One more Thing, what's the purpose of the 1N4148?

[pebe]

When the relay is on and then is suddenly switched off, the energy stored in its inductance generates a high voltage in the reverse direction. So the end of the winding connected to the collector tries to go highly positive.

Without the diode the voltage would be high enough to damage the transistor. But the diode conducts, absorbing the power, and limits the collector voltage to about +12.8V

[julienfhd]

The project was a success, thank you very much...
I did some modification though, like adding an inverter to successfully include the sensor to the circuit; and the motor I used had its polarity controlled by a third wire, so I did some tweaking to the relay's output, but I couldn't have done it without you.
Really Pebe, you were a lifesaver

[pebe]

I'm pleased it all went well for you.