Hello I am looking for a component but I don't know if it exists. I need something that will detect vibration and switch a circuit on but when vibration stops it will switch the circuit off. If anyone can help me I would be grateful.
It depends what you mean by "vibration". For air pressure vibrations at 20-20kHz - sound - you can use a microphone as a sensor. For seismic-type vibration, you could use an accelerometer. Define the frequency range you want to detect.
Once you have something to sense the vibrations, you may need to amplify or condition the signal. For instance a comparator could be used to digitize the sensor output to on or off.
Finally you could use a simple 555 timer IC circuit called a "missing pulse detector". If the sensor fails to send a signal to and and tickle the 555 within a time interval you specify, the 555 will change its output state. Depending on what your circuit is, the 555 may be able to switch it directly. Otherwise you may need a transistor or even a relay to switch the load.
Hi Chris,
I do not think there a single component for your job.
You could use an accellerometer to detect the vibrations.
There are some accelerometers modules on the market that have all the relevant circuitry ready.
All have to do is read the voltage produced at the output and decide what to do with it.
You could connect the accelerometer to an OP Amp witch in turn will turn a switch on and off.
Thanks to all of you for the help I might need to explain myself better.... I have a system set up that includes a 555 timer and a solenoid, the timer controls the solenoid and tells it when to go off, I need to set it up so that the timer switches on when it senses vibration like a motorbike frame and switches off when the vibration stops. I hope I have explained more.