9. December 2010
For this prototype we used seven vibrator units each with a diameter of a approx. 8mm. To avoid too much voltage going back into the micro-controller we utilized a diode, a transistor and a 1k Ohm resistor for each vibrator.Front
![](../../../../files/2010/12/vibUnit_prototype01.jpg)
Back
![](../../../../files/2010/12/vibUnit_prototype00.jpg)