Miscellaneous
Circuit / Schematic diagram | Description |
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Able to handle nine telephone set at different location using a single telephone line. |
Hold Tone for Telephone | Based on UM66 |
Telephone hold with music | |
Door Phone Intercom | |
Full duplex door phone | |
DTMF Tone Decoder | Displays telephone numbers decoded from tones |
Simple PBX | |
Message waiting flasher | This circuit starts flashing when the phone rings and continues flashing it until the phone is picked up to remind you to check your voice- mail. |
Telephone in use indicator | It will allow users to know if the phone is being used. |
Off line telephone tester | Test telephone equipment without connection to a telephone line |
Single number auto dialer | Always dials a single number when handset is lifted |
Cellular phone base audio mute switch | Mute your audio devices when a phone call is received. |
Cut phone line detector | Detects the discontinuity in telephone line. |
Phone line tester | |
Secrecy for Parallel Telephone | |
Telephone Line Vigilant | Protects the misuse of telephone. |
Four line internal intercom | This Link provides four internal intercom phones with no outside line access. |
The Link telephone Intercom | |
The Link telephone Intercom 2 | DTMF version |
Two phone line link | This is the circuit that sparked off all the other Link Telephone Intercom designs. |
Telephone dial alarm | Microcontroller based. |
Telephone line base audio muting | The circuit would automatically light a bulb on arrival of a phone ring and simultaneously mute the music system/TV audio. |
Telephone based Remote Control | It enables switching ‘on’ and ‘off’ of appliances through telephone lines. |