cell_phones_circuits

Cell-Phone-Controlled Audio/Video Mute Switch: 

Cellular Phone calling Detector:  Flashes a LED when detecting an incoming call.  Powered by one 1.5V cell

Cordless Phone Backup: 

Dualvoltage Supply Powers SIM Card:  01/20/00 EDN-Design Ideas / PDF contains multiple circuits - scroll to find this circuit.

Mobile Cellphone Charger: 

Tiny Efficient High Power LED Camera Flash Solutions for CellPhone Applications:  Linear Technology Design Note 1009 Passive filter cleans up power line communications: 09/20/2001 EDN - Design Ideas / Many applications require the design of custom analog filters (Reference 1). The application for this design required simple and low-cost I/O filters for PLC (power-line communications), where low power consumption is a crucial factor. Figure.