Uk hookup chatbox
The core moves back, contact is made once again and the process starts all over again.The core is usually connected to a sounding board (in better buzzers) to produce the noise, or in cheaper buzzers they just let the core movement produce the noise.The upside of the buzzer is you just apply volts and it works.The downside is that you have a COIL which is being switched on/off by it's own integral interruptor.Hi Koossa, I always use a GP transistor to drive either a buzzer or piezo.I think the differences are 1) the sound they make and 2) buzzers are more mechanical and a piezo is not.
I have some small 6volt buzzers that I bought from Jameco and a 2n2222a is just fine for driving it. When you apply a voltage, the coil energises, mechanically moves a core (usually soft iron) which in turn breaks a contact.
I was hoping someone else would jump on your question before me but since that didn't happen I thought I would take a shot at it.
I think the buzzer issue also has to take into consideration what size buzzer you are using and how much current does it draw.
A piezo sounder is a piece of crystal which changes shape (moves) when you apply a voltage across it (kinda like when you get strapped into old sparky).
The movement is constant depending on the mechanical properties of the crystal.
The upside of the piezo sounder is (a) low power, they have an impedance of meghoms therefore require next to no current to drive them, (b) they DO require a voltage to excite the piezo material but it can be as low as 1.5v, (c) they make a hell of a noise when you hit their resonant frequency.