Telephone and Intercom Circuits (01)

Circuit Collection: Telephone, Ring Indicators, Modulators, Incoming call, indicators, Relay Circuit, Audio Interfacing, Caller ID, PBX, PABX, Busy Indicator, FM Telephone Bug, Phone Tap, Recorder, Modem, music on hold, Line in use indicators, Phone Off-Hook Indicators, Line Monitor, Intercom, DTMF decoder, logger, Telephone amplifier, privacy adapter, ringing circuits, automatic dialler, Light Flasher

About Project Links

• Telephone recording circuit
• Infinity Transmitter Schematic and Plans
• Digisound ring modulator
• Incoming call indicator
• Telephone Ring Generator Using 60Hz Power Transformer
• Telephone Ring Generator Using Switching Power Supply
• Telephone In-Use LED Indicator
• Telephone In-Use Relay Circuit
• Telephone Audio Interface
• Telephone interfacing / caller ID using a PIC microcontroller
• Home made PBX / PABX
• Ringing Phone Light Flasher
• Phone Busy Indicator
• FM Telephone Bug
• Cut Phone Line Detector
• Simple Phone Tap
• Telephone Hold Button
• Telephone Recorder
• 300 baud modem circuit schematic
• Telephone music on hold box
• Telephone ring controlled relay
• 1-line telephone status indicator (PDF)
• Line in use indicator (PDF)
• 4-line telephone status indicator (PDF)
• Caller ID decoder
• Telephone in use light
• Detecting a telephone RING
• Phone In-Use Light
• Phone to audio interface
• Phone Off-Hook Indicator
• ‘phone rang’ indicator light
• Phone Line to Audio
• Phone in-use