Vector graphics phone ring stock illustrations Vibration alert in smartphone line and solid icon, smartphone... Vibration alert in smartphone line and solid icon, smartphone concept, mobile call sign ...

Well, it’s not exactly $250, but a deal on the health-tracking wearable that brings it down to $279.99 ($120 off) at Amazon ...

NOTE This project is somewhat incomplete. The finished product was able to ring a modern electronic telephone, but it wasn't able to drive the physical clapper on an older phone. I didn't pursue it ...

Abstract: A new type of telephone receiver is described, in which the permanent magnet, the pole piece and the armature, which drives a light weight dome, are all ring-shaped parts. This structure ...