Telephone

This circuit will allow you to record both sides of your telephone conversations for future reference. For commercial orders placed over the phone such a recording device is invaluable.
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This device connects to the telephone line and can be used to remotely control up to 4 relay outputs using a DTMF (tone dialing) telephone. A number of user settings are available to improve the useability and security of the device. The kit comes complete with a small plastic case with silk-screened front and rear [...]

The DTMF decoder can be directly connected to a Serial port to view the digits in HyperTerminal on a computer. The decoder stores the last 234 received digits in EEPROM. The contents of EEPROM can be viewed on the LCD screen via two scroll buttons. Total power consumption is 12mA. The DTMF decoder has two [...]